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Stargazer Columns 2004


Dec. 18, 2004: Huygens at Titan
Dec. 04, 2004: The Moon Occults Jupiter
Nov. 20, 2004: Are There Any Planets Beyond Pluto?
Nov. 06, 2004: Buying a Telescope?
Oct. 23, 2004: Venus-Jupiter Conjunction
Oct. 09, 2004: Total Eclipse of the Moon Oct. 27
Sep. 25, 2004: Shine On Harvest Moon
Sep. 11, 2004: Do Stargazers Really Stargaze?
Aug. 28, 2004: My Journey to the Stars Began 50 Years Ago
Aug. 14, 2004: Voyager 2 Encountered Neptune 15 Years Ago This Month
Jul. 31, 2004: This Year's Perseid Meteor Shower Better than Average?
Jul. 17, 2004: Shoemaker-Levy 9 Crashed into Jupiter 10 Years Ago
Jul. 03, 2004: Early Evening Shows Feature Two Planets and a Star Cluster
Jun. 19, 2004: Cassini-Huygens Mission to Saturn: Part II
Jun. 05, 2004: Cassini-Huygens Mission to Saturn
May 22, 2004: Circumpolar Region: Where the Stars Never Rise or Set
May 08, 2004: Updates on Comets NEAT and LINEAR
Apr. 24, 2004: Comets NEAT and LINEAR
Apr. 10, 2004: Planets in the Evening Sky
Mar. 27, 2004: Nature's Game
Mar. 13, 2004: Moon's Guided Tour of the Planets
Feb. 28, 2004: Leap Day and Nature's Imperfections
Feb. 14, 2004: Copernicus, the Scientific Revolutionary
Jan. 31, 2004: What We See in the Night Sky
Jan. 17, 2004: Seeing Mercury in the Morning
Jan. 03, 2004: Night Sky Highlights for 2004


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December 18, 2004

Huygens at Titan

It's nearly time for the Huygens probe to visit Saturn's largest moon, Titan. The Cassini spacecraft, on which the probe is riding piggy-back, left Earth in 1997, and after its nearly 7 year journey, reached the ringed planet last summer.

Now in orbit around Saturn, Cassini's 12 scientific instruments are returning dazzling images and a wealth of information about the planet, its famed rings and several of its nearly three dozen moons. It should continue doing do so for another 4-8 years.

But in one of the most exciting components of the entire Cassini-Huygens mission, we should soon discover some of the secrets of the solar system's most intriguing moon, Titan.

On Dec. 25 the Huygens probe will separate from Cassini, coast in space for 20 days, then reach Titan Jan. 14. High above the moon's surface, a parachute system will slow the probe. During its 2+ hour descent to the surface, a camera will take over 1,100 images while 5 other scientific instruments gather data. Should the probe survive the landing, it will continue returning images and valuable scientific information for a few more minutes. All data will be sent to the Cassini which will relay it to Earth.

For a moon, Titan is huge, second only to Jupiter's Ganymede. It's larger than Mercury and Pluto and not much smaller than Mars. But what makes it unique is its atmosphere--no other moon has one. And its atmosphere has remarkable similarities to our's--both are composed mostly of nitrogen, and Titan's is just a bit more dense. It seems more Earth-like than Venus or Mars.

Yet with no atmospheric oxygen and extremely cold temperatures, it's not a place we'd be comfortable. While not ruling out the possibility, scientists don't expect to find evidence of past or present life on Titan. But they do think it might resemble "prebiotic" Earth before life evolved. So, in learning about Titan, we just could learn more about us and our origins.

  • Next Two Weeks: Average sunrise: 7:26 a.m.; average sunset: 5:32 p.m. (for Waco, TX)
    * Today (Dec. 18) the Moon is at 1st quarter.
    * Tomorrow (Dec. 19) is Saturnalia, the ancient Roman festival honoring the god Saturn, father of Jupiter.
    * Tuesday (Dec. 21) is the winter solstice, the Northern Hemisphere's shortest day and longest night of the year, and the first day of winter.
    * The Dec. 26 full Moon is called the Long Night Moon and the Moon Before Yule. (Since Yule, a pagan winter festival co-opted by early Christians, now refers to Christmas, this full Moon should be called Moon After Yule.)
    * The morning of Dec. 28 the Moon is above Saturn.
    * The last few mornings of December and first few mornings of January Venus and Mercury pass within two moonwidths of each other low in the east shortly before sunrise.

  • Naked-eye Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Saturn rises an hour after dark, is up all night, and is low in the west by morning. 45 minutes before sunrise, Mercury, Venus and Mars are aligned in the southeast with Mercury near the horizon, brilliant Venus a little to the upper right and reddish Mars further to the upper right. Brighter than any star, Jupiter looks down on the others from half way up. (Mercury is at its best Dec. 29.)

  • Astronomy Class: The Stargazer's 4-session "Learning the Night Sky" class is Jan. 3-6 from 7-9 p.m. The cost is $25 per person with family discounts and scholarships available. Call or email for information or to register.


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December 4, 2004

The Moon Occults Jupiter

Since the planets in our solar system orbit the Sun on nearly the same plane, the Sun and planets travel across our sky along a common path called the ecliptic. The ecliptic is like a sky highway with the Sun's path as the center stripe. The planets travel along the highway but not exactly on the center stripe. And as the Moon orbits Earth it also follows this path.

Since the Moon and planets move at different speeds, the faster ones frequently pass the slower ones. These passings often produce close alignments called conjunctions, like when Venus passed Jupiter in early November. Occasionally an object, usually the Moon, passes directly in front of another object and briefly hides it in what is called an occultation.

The early morning hours of Dec. 7 a crescent Moon occults Jupiter and its moons. In a telescope the largest four moons look like tiny stars aligned on either side of the planet, so not only will we see Jupiter disappear and then reappear from behind the Moon, we'll get to watch three of the moons do the same.

A viewing location with a clear view of the eastern horizon will be essential for seeing the nearly two hour show. The occultation of Jupiter can be seen with naked eyes or binoculars, however, a telescope--even a small one at low power--will be needed to watch the moons disappear and reappear.

The Moon rises at 2:22 followed by Jupiter at 2:25. (All times are a.m. and approximate, depending upon one's viewing location.)

With the Moon low above the horizon, the objects disappear from the illuminated edge of the Moon's crescent near the lower horn. First Callisto disappears at 2:52 followed by Ganymede at 2:57, then Jupiter at 3:00 and Europa at 3:02.

The objects emerge from the shadowed side of the Moon and will be easier to see. First is Callisto at 3:21 followed a minute later by a faint star. Ganymede emerges at 3:32 with Jupiter reappearing at 3:35 and Europa at 3:38.

But keep watching Jupiter. As a final treat, the fourth moon Io, which has been hiding behind Jupiter the entire time, emerges from behind the planet at 4:07. After the show you'd better go to bed and try to get some sleep before you have to get back up!

  • Next Two Weeks: Average sunrise: 7:18 a.m.; average sunset: 5:26 p.m. (for Waco, TX)
    * The Moon is at 3rd quarter today (Dec. 4).
    * Tomorrow and Monday mornings (Dec. 5 & 6) Venus and Mars are two moonwidths apart low in the east before dawn.
    * Wednesday morning (Dec. 8) the crescent Moon is below Virgo's brightest star, Spica, in the east.
    * Thursday morning (Dec. 9) the crescent Moon is above Mars, which is just above Venus, low in the southeast an hour before sunrise.
    * The Moon is new Dec. 11.
    * The Geminid meteor shower which peaks the night of Dec. 13/14 promises to be a good show: the Geminids are one of the best of the annual showers, the constellation Gemini from which the meteors seem to come is up most of the night, and the Moon will not interfere this year.

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Saturn rises around 8:30 p.m. and is high in the west by morning. An hour before sunrise Venus and Mars are low in the east southeast with Jupiter midway up in the southeast.

  • Astro Milestones: Dec. 14 is the 458th anniversary of the birth of Danish astronomer Tycho Brahe (1546-1601).


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November 20, 2004

Are There Any Planets Beyond Pluto?

In a recent email Richard Zowie asked: "Do you think there are any planets beyond Pluto?" His question is a good one that cannot answered with a simple yes or no.

One answer is yes, and probably billions of them--orbiting other stars. Using indirection observations, astronomers have, since the first discovery in 1995, found some 140 "extrasolar" planets, and the number is growing. University of Texas astronomers recently discovered a distant planet with McDonald Observatory's Hobby-Eberly Telescope in Ft. Davis, TX.

But, of course, Richard, meant other planets in our solar system. The answer to that depends largely on one's definition of a planet, and surprisingly, there is no precise, agreed-upon definition among professional astronomers. In addition to the 9 officially recognized major planets, there are many smaller minor planets (also called asteroids and planetoids). Both major and minor planets are nonluminous objects that orbit the Sun and shine by reflecting sunlight.

The problem arises in distinguishing between major and minor. Some suggest that since Pluto is smaller than several solar system moons (including ours), it is not a major planet. But even Mercury is smaller than Jupiter's moon Ganymede and Saturn's Titan, so should it be demoted as well?

Since 1993 astronomers have discovered some 1,000 objects in the Kuiper Belt, the realm of the solar system beyond Neptune (somewhat akin to the Asteroid Belt between Mars and Jupiter). The discovery earlier this year of the largest known Kuiper Belt object (KBO), given the name Sedna, has led some to suggest that perhaps Pluto is just a large KBO. Orbiting far beyond Pluto, Sedna is larger than any known asteroid and not much smaller than Pluto, so should it be considered the 10th major planet?

The International Astronomical Union, founded in 1919, has the final say, and it says yes to Pluto and no to Sedna. So back to Richard's question, are there any major planets beyond Pluto? Probably not. Are there more Sedna-like minor planets? Probably.

  • Next Two Weeks: Average sunrise: 7:07 a.m.; average sunset: 5:25 p.m. (for Waco, TX)
    * Friday's (Nov. 26) full Moon of November is called the Frosty Moon and Beaver Moon.
    * The evening of Nov. 30 Saturn and a bright gibbous Moon rise together in the east around 9 p.m. and are high in the west the next morning.
    * The morning of Dec. 3 Mars is a less than a moonwidth from Libra's brightest star, Zubenelgenubi. With a name that sounds like it came from "Star Wars," this star has a faint companion star which is easily seen in binoculars. Venus is just above Mars, so the two planets and the double star can all be seen in the same binocular (or telescope at very low power) field of view.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Mercury is hovering near the southwestern horizon 45 minutes after sunset, and Saturn rises in the east northeast a little after 9 p.m. Morning: Mars, Venus and Jupiter are aligned above the east southeastern horizon. Highest is Jupiter which rises at 3:20 a.m., then Venus which comes up at 4:30 a.m. and nearest the horizon is Mars rising at 5:15 a.m.

  • Astro Milestones: Today is the 115th anniversary of the birth of American astronomer Edwin Hubble (1889-1953) for whom the Hubble Space Telescope is named.


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November 6, 2004

Buying a Telescope?

The gift-giving season is nearly here, and if you or a loved one has a new fascination with the night sky, you might be considering a new telescope. While a telescope can enhance one's enjoyment, it's not something to buy at the last minute.

The wrong choice can do more to dampen than enhance one's interest. The following might help in your considerations.

Cost. Prices range from less than $100 to thousands of dollars. While the least expensive models are generally not recommended, few can afford the costlier ones. A few hundred dollars, spent wisely, can purchase a satisfying scope.

Binoculars. If you can't spend that much right now, $100 can purchase a decent pair of binoculars. Virtually all stargazers, even those with large scopes, own and use binoculars.

Power. A telescope's power is not fixed but is set by the size of the eyepiece which is quickly changeable, thus power depends upon the size of eyepiece being used at the moment. Most scopes come with two or three eyepieces yielding different powers, and additional ones can be purchased.

Size. The more relevant consideration is a telescope's aperture (diameter). The larger the aperture, the more light the scope will gather. Thus one can see fainter objects, and the scope can be "pushed" to higher powers before the image becomes too fuzzy.

Types. There are different types of telescopes, such as refractors, reflectors and Cassegrains. And there are different types of mounts which hold and help you aim your telescope, such as equatorials, forks, altazimuths and Dobsonians. Since no type of scope or mount is inherently better than another, your choice should be based on your intended uses and preferences.

Using. Telescopes have a learning curve--some more than others. If possible get with an experienced user for some pointers to help jump-start your learning. Many local astronomy clubs offer free hands-on "how to use" sessions after the holidays, so watch for announcements.

If you live reasonably near Austin, TX, I recommend you visit a small store named Austin Astronomy. While I've yet to meet these folks, I've heard only good reports. They take time to talk with you, they don't pressure you to make a purchase, and since they are also stargazers, they know about telescopes. Find out more about them at: austinastronomy.com or 512-250-1252.

Sky Publishing's 6-page "Choosing Your First Telescope" is helpful. For a free copy send me your name and address.

  • Next Two Weeks: Average sunrise: 6:55 a.m.; average sunset: 5:31 p.m. (for Waco, TX)
    * Nov. 9 Tue. morning: the crescent Moon is above Jupiter low in the east.
    * Nov. 10 Wed morning: This morning will be even better with a lineup of 5 objects in the east an hour before sunrise -- nearest the horizon is Mars; next up is Virgo's brightest star, Spica; then a thin crescent Moon, above which is Venus and then Jupiter.
    * Nov. 12 Fri.: The Moon is new.
    * Nov. 16/17 Tue. evening/Wed. morning: The Leonid meteor shower peaks.
    * Nov. 17 Wed.: Venus is to the left of Virgo's brightest star, Spica.
    * Nov. 18 thu.: The Moon is at 1st quarter.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Mercury is near the western horizon 1/2 hour after sunset. Morning: An hour before sunrise look for Mars just above the eastern horizon with brilliant Venus and Jupiter a little further up. Saturn is high in the south.


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October 23, 2004

Venus-Jupiter Conjunction

The two brightest planets, Venus and Jupiter, will pass breathtakingly close to one another the mornings of Nov. 4 and 5. Called a planetary conjunction by astronomers, this is a celestial event you won't want to miss.

If you're a morning person, you can watch the drama develop. Venus rises 3 hours before the Sun with Jupiter coming up an hour after Venus. Currently separated by 12 degrees, they move 1 degree closer each morning. (Held at arm's length, the width of your fist is 10 degrees and the width of your index finger is 1 degree. The width of a full Moon is 1/2 degree.)

Other than the Moon, Venus is the brightest object in our night sky, and like the Moon and other planets, it only reflects sunlight. It is so bright because it comes closer to us than any other planet, it's nearer the light source (the Sun), and being shrouded in thick clouds, it's more reflective than any other planet. It bounces back 65% of the sunlight striking its cloud cover (compared with our rocky Moon's reflectivity of only 7%).

Named after the ancient Greek goddess of love and beauty, Venus is the "morning star" or the "evening star." Some once believed it to be a tropical paradise harboring life, but space probes have shown it to be anything but a paradise, with 900-degree temperatures, crushing air pressure and clouds of sulfuric acid.

Jupiter, although far more distant than Venus, is the second brightest planet, partly because it is 10 times larger than Venus. And being a gas planet, it nearly matches Venus' reflectivity, returning 52% of the sunlight striking it.

Named after the king of the gods, Jupiter is not a planet astronauts will explore like they did the Moon in 1969-71. Gas planets have no surface on which to land or walk.

The planets will be only 1/2 degree apart at 7 p.m. Nov. 4, but that's several hours before they rise. So when we will see them Nov. 4 & 5 they will be separated by 3/4 degree--still quite close. Rising in the east 3 hours before the Sun, they will be 20 degrees above the horizon an hour before sunrise with Venus to Jupiter's upper left Nov. 4 and its lower left the next morning.

As this will be an event not to miss, even this incorrigible nightowl plans to get up for it.

  • Lunar Eclipse: Don't forget Wednesday's total eclipse of the Moon. Partial eclipse begins at 8:14 p.m. and ends at 11:54 p.m. with total eclipse lasting from 9:23 to 10:45 p.m.

  • Next Two Weeks: Average sunrise: 7:43 a.m.; average sunset: 6:41 p.m. (for Waco, TX; times will be an hour earlier after the Oct. 31 time change.) Oct. 31 is Halloween, a traditional cross-quarter day celebrating the middle of fall. The morning of Nov. 3 the Moon is to the lower right of Gemini's brightest star, Pollux, and to the upper right of Saturn high in the south. The Moon is at 3rd quarter Nov. 4.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Mercury is too near the evening Sun for easy viewing. The other naked-eye planets are visible in the morning. At 6 a.m. Saturn, which rises after midnight, is high in the southeast and Mars rises an hour before the Sun. (Venus and Jupiter were discussed above.)

  • Time Change: Before retiring Oct. 30, set your clocks back ("fall back") one hour to Standard Time.


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October 9, 2004

Total Eclipse of the Moon Oct. 27

The October 27 full Moon will feature a total eclipse of the Moon, and for most of the Americas, the timing couldn't be better. An evening event concluding before midnight, we'll get to follow the entire eclipse at a convenient hour.

Partial eclipse begins at 8:14 p.m. when shadowing appears at the edge of the Moon. The shadow then creeps across the the Moon until it becomes totally eclipsed at 9:23. The total eclipse lasts until 10:45 when sunlight then begins moving back across the Moon's surface. Partial eclipse ends at 11:54.

Depending upon the Earth's atmospheric conditions, the totally eclipsed Moon may appear anywhere from a deep coppery orange to almost invisible gray. When our atmosphere is reasonably free of clouds, dust and smoke, more redder rays of sunlight are bent into Earth's shadow, bathing the Moon with a beautiful, but eerie color. But when our atmosphere is less clear, little sunlight is bent into the shadow, leaving the Moon looking darker.

The Moon orbits Earth every 29 1/2 days (each "moonth") on nearly the same plane as Earth orbits the Sun. During new Moon, the Moon passes between the Earth and Sun, and is hidden in the Sun's glare. During full Moon, Earth passes between the Moon and Sun, and we see the Moon fully illuminated.

Since the plane of the Moon's orbit around Earth is not exactly the same as Earth's plane around the Sun, most alignments are not exact, but when they are we have an eclipse. During those new Moons when the Moon passes exactly between Earth and Sun, it blocks out sunlight for a few minutes, producing a solar eclipse. During those full Moons when the Moon passes directly through Earth's shadow, as it will Oct. 27, we have a lunar eclipse.

If you're observing this eclipse from a non-light polluted area notice that as the Moon darkens more stars pop out, and even the Milky Way should be visible during totality. (But don't look for any naked-eye planets during the eclipse -- they're now in the morning sky.)

We won't see another total eclipse of the Moon until Feb. 2008, so mark your calendar now. And after last November's clouded out lunar eclipse, let's hope for better luck this year.

  • Next Two Weeks: Average sunrise: 7:32 a.m.; average sunset: 6:55 p.m. (for Waco, Tx)
    * Tomorrow (Oct. 10) morning brilliant Venus, the crescent Moon and Leo's brightest star, Regulus, form a triangle in the east.
    * Tues. (Oct 12) morning the thin crescent Moon is above Jupiter near the eastern horizon 45 minutes before sunrise.
    * The Moon is new Wed. (Oct 13), producing a partial eclipse of the Sun which won't be visible from the U.S.
    * The evening of Oct 16, the crescent Moon is to the lower right of Scorpius' brightest star, Antares, low in the west, then the next night is to the star's upper left.
    * The Moon is at 1st quarter Oct. 20.
    * The night of Oct.20/21, the Orionid meteor shower peaks with the best viewing expected from midnight, when the Moon sets and Orion is well up, until dawn.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) With Mars and Mercury now too near the Sun for viewing, the remaining naked-eye planets are seen in the morning in the east. Highest is Saturn which rises at 1 a.m. The brightest starlike object, "morning star" Venus, comes up 3 hours before sunrise. Jupiter, rising only an hour before the Sun, is seen near the horizon as dawn breaks.


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September 25, 2004

Shine On Harvest Moon

The September 28 full Moon is this year's Harvest Moon. But in spite of some popular misconceptions, don't expect it to look larger, brighter or more orange than other full Moons.

Full Moons occur when the Moon is on the opposite side of Earth from the Sun, and the entire side facing us is illuminated by sunlight. At this phase, the Moon rises at sunset, is in the sky all night, and sets at sunrise.

While some full Moons are larger and brighter than average (and some smaller and less bright), it has nothing to do with seasons. Owing to the Moon's slightly elliptical orbit around Earth, once during each orbit it is nearer to us (called perigee) and once farther away (called apogee). At perigee it does appear slightly larger and brighter, but any month's full Moon is equally likely to coincide with perigee (or apogee)--not just the Harvest Moon.

The Moon appears orange when seen near the horizon soon after it rises and before it sets, but the color comes from Earth's atmosphere. When the Moon is nearer the horizon, we see it through more atmosphere than when it's higher in the sky, so all full Moons appear orange shortly after moonrise.

But Harvest Moons are different from other full Moons. Each night, on average, the Moon rises 50 minutes later than it did the previous night, however near the fall equinox, moonrise comes only 30 minutes later than the night before. So for several nights in a row the Harvest Moon comes up around the time the Sun is setting, and, it is said, illuminated fields so farmers (before tractors had lights) could more easily harvest crops by moonlight--hence the name, Harvest Moon. Also during this time, the Moon's trajectory is less steep, keeping it nearer the horizon longer. So while it's not more orange, it does stay orange a little longer.

The Harvest Moon is the full Moon nearest the Sept. 22 (this year) fall equinox. While most Harvest Moons come in September, some fall in October. The origins of full Moon names is not certain. Some come from English traditions, some from Native Americans, and some were likely made up by early almanac writers. None, however, have official standing in professional astronomy.

  • Next Two Weeks: Average sunrise: 7:23 a.m.; average sunset: 7:12 p.m. (for Waco, Tx)
    * The morning of Oct. 3 Venus is less than a moonwidth to the upper right of the star, Regulus, in the east. Although Regulus is the 21th brightest star in the night sky, it pales in comparison to Venus' brilliance.
    * The Moon is at 3rd quarter Oct. 6.
    * The morning of Oct. 7 the Moon is to the left of Saturn in the east with the Gemini twins, Pollux and Castor, above them.
    * The night of Oct. 7 the Draconid meteor shower peaks. The constellation Draco from which the meteors seem to come is highest in the early evening, so the best viewing window is from dark until moonrise at 2 a.m.
    * The morning of Oct. 8 the Moon passes to the left of the Beehive star cluster, but seeing the cluster will require binoculars because of the Moon's glare.

  • Planets: All the naked-eye planets are in the morning sky although Mercury, Mars and Jupiter are hiding near the Sun. Saturn rises at 2 a.m. and Venus comes up 2 hours later.

  • Astronomy Class: The Stargazer's 4-session "Learning the Night Sky" class is Oct. 4-7 from 8-9:30 p.m. The cost is $25 per person with family discounts and scholarships available.

  • Astro Milestones: Oct. 4 marks the 47th anniversary of Russia's 1957 launch of Sputnik I, Earth's first artificial satellite, and the beginning of the space age.


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September 11,2004

Do Stargazers Really Stargaze?

Do stargazers really gaze at stars? Actually, no--and yes. People attending star parties for the first time often ask to see a bright star in a telescope, but ironically, viewing a solitary star is pretty boring. Stars, even bright ones, are so distant that in telescopes they just appear as bright points of light-- not too exciting. So we just don't do it much.

(Of course, individual stars are of interest to professional astronomers who learn much studying them, and some stargazers observe stars whose brightness varies, called variable stars.)

Of more interest to many stargazers are solar system objects like planets, moons, meteors and comets. While they orbit a star (our Sun), they are not stars themselves. (The Sun is sometimes viewed by those knowing how to do so safely with solar filters.)

So, no, stargazers don't spend much time looking at SINGLE stars. Yet, beyond the solar system, in what we call the deep sky, virtually all we see are stars in one form or another.

With naked eyes we look at arrangements of stars in imaginary patterns we call constellations. And we view stars with visible companions, called double, binary and multiple stars, which are especially dazzling when they are of contrasting colors.

We view stars in groups called star clusters. The relatively nearby ones, called open clusters, are composed of dozens to hundreds of stars, while much further away we see larger globular clusters containing many thousands of stars.

We observe stars beginning their lives in star-forming nebulae and ending their lives as planetary nebulae and supernova remnants. Finally we look at huge groupings of billions of stars called galaxies, the largest, most distant objects in our cosmos.

So while we spend little time looking at single stars, nearly all that stargazers gaze at beyond the solar system are stars.

  • Next Two Weeks: Average sunrise: 7:14 a.m.; average sunset: 7:29 p.m. (for Waco, TX)
    * Tomorrow morning (Sep. 11), shortly before dawn, the thin crescent Moon is above the star Regulus and the brighter planet Mercury low in the east.
    * Monday morning (Sep 12) Venus is to the right of the Beehive star cluster in the east; Venus is so bright that binoculars may be needed to see the large but much fainter Beehive.
    * Tuesday (Sep. 14) the Moon is new--between Earth and Sun.
    * Mars is in conjunction with (aligned behind) the Sun Wednesday (Sep. 15).
    * Thursday evening (Sep. 16) the crescent Moon is to the upper right of Virgo's brightest star, Spica, low in the southwest.
    * The evening of Sep. 19 the Moon is to the right of Scorpius' brightest star, Antares, in the southwest.
    * Sep. 21 the Moon is at 1st quarter, and Jupiter is in conjunction with the Sun.
    * Fall (autumn) equinox occurs Sep. 22, when night and day are of equal length.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) There being no evening sky naked-eye planets with Mars and Jupiter now in the Sun, all the action is in the morning. Saturn rises more than 4 hours before the Sun with "morning star" Venus coming up an hour or so later. Mercury can still be seen low in the east before sunrise.

  • Astronomy Class: The Stargazer's 4-session "Learning the Night Sky" class will be held Oct. 4-7 from 8-9:30 p.m. The cost is $25 per person with family discounts and scholarships available. Call or email for information or to register.


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August 28, 2004

My Journey to the Stars Began 50 Years Ago

Many who love the night sky can recall the origins of their love affair with the heavens, a story I call one's personal journey to the stars. My journey began 50 years ago this month at my boyhood home on Galveston Bay, and my unlikely tour guide was an octogenarian named Margaret Willits.

My mother's high school art teacher 20 years earlier, Ms. Willits lived in a Houston retirement home. Still active at 81, she spent time with us in 1954 to do Bay paintings. Some nights she would take me outside and dazzle me with her enthusiasm and familiarity with the stars, constellations and planets.

My 14-year-old ears really perked up as she told me of seeing Halley's Comet in 1910, and when she said someday I would get to see it, my personal journey to the stars was underway. Although interrupted for three decades by school, family, career and other interests, my journey resumed in earnest in the 1980s as Halley's return loomed nearer.

Born in 1872, Margaret Willits grew up in Indiana, and after college and marriage, she and her husband moved to Webster, TX, in 1906 where he farmed and she taught art and music. In a 1971 letter to my mother, when Ms. Willits was 98 and growing infirm, she wrote: "I keep my spirits up and am always on the hunt for something I can do to brighten the world for those near me."

While I never learned how she became interested in astronomy, I suspect Comet Halley played a role for her as it did for me. And although she missed its 1986 return, she came closer than either of us would have ever imagined. She died in 1974 at age 101.

The constellation Cassiopeia the Queen has become for me a reminder of Ms. Willits. Its five brightest stars form the letter M (when they are above Polaris) and W (when below it)--the initials of Margaret Willits. (Surely this coincidence occurred to her, although I never heard her mention it.)

Cassiopeia, circumpolar from our latitudes, is nearly always above the horizon and visible any time of night, any night of the year. Since I can almost always see Cassiopeia, I think of Ms. Willits and never feel alone under the stars. I'm always in the company of my first stargazing companion, that wonderful woman who opened my young eyes to the grandeur of the night sky, and who, 30 years after her death, still brightens my world.

  • Next Two Weeks: Average sunrise: 7:06 a.m.; average sunset: 7:47 p.m. (for Waco, TX)
    * Tomorrow (Aug. 29) night's full Moon is called the Green Corn Moon and Grain Moon.
    * Tuesday (Aug. 31) morning Venus and Saturn pass near each other with the much brighter Venus to the right.
    * The Moon is at 3rd quarter Sep. 6.
    * The morning of Sep. 10 the crescent Moon, Saturn and Venus form a triangle in the east with Venus at the bottom. Just below them look for Mercury very near Leo's brightest star, Regulus. Just above the eastern horizon 45 minutes before sunrise, the brighter planet will be less than the width of a full Moon below the star. While it should be visible to naked eyes, binoculars will enhance the view.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: The evening planetary shows of recent months are all but over. Mars is slipping into to the setting Sun and Jupiter is barely visible low in the west at dusk. Morning: Venus and Saturn rise more than 3 hours before the Sun. Mercury, seen low in the east just before sunrise, is at its best Sep. 9.


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August 14, 2004

Voyager 2 Encountered Neptune 15 Years Ago This Month

August marks the 15th anniversary of Voyager 2's flyby of Neptune, the only spacecraft to visit and return closeup images of the 8th most distant planet.

In 1977 NASA launched the Voyager mission--twin spacecraft, Voyager 1 and 2. Voyager 1, after encountering Jupiter (in 1979) and Saturn (in 1980), was put on a path that sent it away from the Sun in the direction the Sun is traveling in our Milky Way galaxy. Voyager 2, after also flying by Jupiter (in 1979) and Saturn (in 1981), was sent on to encounters with Uranus (in 1986) and Neptune (in 1989). (Pluto wasn't in position for a visit.)

Orbiting nearly 3 billion miles from the Sun, Neptune is 30 times further from the Sun than we are, and takes 165 Earth-years to circle the Sun. It was discovered 158 years ago in 1846, less than one Neptune-year ago.

Like Jupiter, Saturn and Uranus, Neptune is a giant gas planet with no solid surface astronauts could ever land or walk on. One-third the diameter of Jupiter, Neptune is virtually the same size as Uranus, both of which are four times Earth's diameter.

It's huge size notwithstanding, Neptune's great distance makes it impossible to see without optical aids, and even then it's not much to see through most Earth-based telescopes. It looks like a tiny, bluish, featureless disk that resembles a star more than a planet. (The bluish color comes from methane gas in Neptune's atmosphere.)

Neptune was at opposition early this month, making this the best time of year to see it. A planet at opposition is on the opposite side of Earth from the Sun, is in the sky all night, and is as close to us as it ever gets--which still isn't very close.

Back to the Voyagers. Remarkably both 1 and 2, now more than 25 years old, are still operational and returning valuable data from far beyond the realm of the planets. They are now engaged in what NASA calls the Voyager Interstellar Mission, searching for the outer limits of the Sun's sphere of influence. Both have sufficient fuel and electrical power to continue their mission for another 20 years, by which time they may have reached true interstellar (between the stars) space--a first for humankind.

  • Next Two Weeks: Average sunrise: 6:57 a.m.; average sunset: 8:05 p.m. (for Waco, TX)
    * The Moon is new tomorrow (Aug 15) meaning good moonless stargazing all night.
    * Tuesday evening (Aug. 17) a thin crescent Moon is to the right of Jupiter low in the west.
    * Friday evening (Aug 20) a larger crescent Moon is above Virgo's brightest star, Spica.
    * The evening of Aug. 23 the 1st quarter Moon is very near Scorpius' brightest star, Antares.

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Mercury and Mars are too near the setting Sun for practice viewing. Jupiter is just a bit higher, setting at 9:30 p.m. Morning: The brilliant "morning star" in east is Venus rising more than three hours before the Sun with Saturn coming up an hour later.

  • Public Star Party. Today is the 5th Annual Lake Whitney State Park Star Party featuring daytime activities and evening programs and night sky viewing. Other than the nominal park entrance fee, the star party is free and open to the public. For activity schedules and other information see the Central Texas Astronomical Society website at www.centexastronomy.org.


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July 31, 2004

This Year's Perseid Meteor Shower Better than Average?

The annual Perseid meteor shower, usually one of the year's best, peaks the night of Aug. 11/12, and this year could be better than average. Unlike last year's shower which was washed out by bright moonlight, there will be only a thin crescent Moon and it doesn't rise until 3:30 a.m. Some are predicting an extra abundance of meteors owing to a possible new strand of cometary debris which produce meteors.

As the grandson of a carpenter, I helped clean up around new houses, picking up leftover wood, roofing, bricks and the like. Star formation is like housebuilding in that most, but not all, star-building material goes into the star with the leftover debris becoming planets, moons, asteroids and comets.

Comets, most of which orbit far beyond the planets, are "dirty snowballs" of ice imbedded with sand- to gravel-sized pieces of rocky material. Some, however, wander into the inner solar system where heat from the Sun melts away their outer layers, releasing pieces of debris along the comet's path.

By chance the paths of some comets intersect Earth's orbital path. As Earth, traveling 67,000 miles per hours in its annual trip around the Sun, passes through a comet's path, pieces of cometary debris, also traveling thousands of miles per hour, enter our atmosphere at incredible speeds. Friction makes them burn up, producing those brief but brilliant streaks of light called meteors, also known as shooting stars and falling stars.

Each year this time, Earth passes through the path of Comet Swift-Tuttle, producing the Perseid meteor shower, so named for the constellation Perseus from which the meteors seem to come.

Viewing meteors is so easy and relaxing that staying awake can be a challenge. Find a comfortable place, lay back on a blanket or reclining lawnchair and pan the skies. Perseus rises in the northeast around midnight, but you might start watching around 10 p.m., and the darker your skies, the more meteors you'll see.

  • Next Two Weeks: Average sunrise: 6:49 a.m.; average sunset: 8:20 p.m. (for Waco, TX)
    * Tonight's second full Moon of the month, called a Blue Moon, looks no different than other full Moons.
    * Monday morning the Moon is between Taurus' Pleiades star cluster and brightest star, Aldebaran, in the east.
    * The Moon is at 3rd quarter Aug. 7.
    * The morning of Aug. 11 the crescent Moon is to the upper left of Venus, then to its lower left the next morning.
    * The crescent Moon is to the lower left of Saturn the morning of Aug. 13 (another Friday the 13th to worry the superstitious).

  • Planets: Evening: Mars now sets in the west less than an hour after the Sun while brighter Mercury, to Mars' upper left, sets just over an hour after sunset. "Evening star" Jupiter sets before 10:30 p.m. Morning: Venus, the brilliant "morning star," rises 3 hours before the Sun, and Saturn is up an hour and a half before sunrise.

  • Astronomy Class: The Stargazer's four-session Learning the Night Sky class will be Aug. 2-5, 8-10 p.m. The cost is $25 per person with family discounts and scholarships available. Call or email for information or to register.

  • Astro Milestones: July 31 is the 40th anniversary of the 1964 planned crash of Ranger 7 onto the surface of the Moon. As it approached the Moon, the doomed spacecraft transmitted over 4,000 images, providing the first close-up views of the lunar surface just five years before the first manned landing.


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July 17, 2004

Shoemaker-Levy 9 Crashed into Jupiter 10 Years Ago

July 16-22 marks the 10th anniversary of Comet Shoemaker-Levy 9's piecemeal crash into Jupiter. Over seven days the 21 pieces of the fragmented comet crashed, one by one, into Jupiter's dense atmosphere and vaporized, leaving smudges on the planet that lasted for months and were visible through amateur telescopes.

While such cosmic crashes have undoubtedly happened countless times, this is the only one humans have observed. And this 10th anniversary brings to mind my meeting of one of the comet's codiscoverers.

In 1993 my wife and I were privileged to visit Clyde Tombaugh, and his wife Patsy. (Tombaugh, who died in 1997, discovered the planet Pluto in 1930.) It was with great anticipation that I awaited the visit. At the appointed time, and my heart racing with excitement, we arrived at their residence in Las Cruces, NM.

As Tombaugh welcomed us into his living room, he introduced us to a man who was leaving. Absorbed with my upcoming visit I paid scant attention to the man, politely shook his hand, and gladly saw him leave so we could have the Tombaughs to ourselves.

Even at 87 and in declining health, Tombaugh was a delightful conversationalist. At one point he excitedly said, "You know they just discovered a comet that's going to crash into Jupiter next year, and David was one of the discoverers." To which I replied, "You mean David Levy?" "Of course," he said, a bit perplexed at my question, "the man you just met as he was leaving!" Flabbergasted, I realized that I had met, but didn't recognize, David H. Levy, one of the world's foremost comet discoverers and astronomy authors, soon after he and Gene and Carolyn Shoemaker had discovered their famous comet.

So this 10th anniversary of Comet Shoemaker-Levy 9's crash reminds me, not only of the awesome forces at work in nature, but of my memorable meeting of two of my astronomical heroes.

  • Next Two Weeks: Average sunrise: 6:40 a.m.; average sunset: 8:30 p.m. (for Waco, TX)
    * The Moon is new tonight (July 17).
    * Tomorrow (July 18) evening a thin crescent Moon is to the right of Mars and Mercury near the western horizon 45 minutes after sundown.
    * Early Monday (July 19) evening the crescent Moon is to the right of the star, Regulus, and above Mercury low in the west.
    * Tuesday (July 20) evening the crescent Moon is to the right of Jupiter, then the next night to the planet's upper left.
    * Friday (July 23) evening the Moon is right of the star, Spica.
    * The evening of July 24 the Moon is at 1st quarter, and Mercury passes below fainter Regulus low in the west.
    * The Delta Aquarid meteor shower peaks the morning of July 27 with the best viewing between 2 a.m. (after the Moon sets) and dawn.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Mars is falling lower each evening, now setting an hour after the Sun. Brighter Mercury to Mars' upper left gets higher each evening until July 26. Jupiter, the brightest starlike object in the west, sets at 11 p.m. Morning: "Morning star" Venus rises nearly 3 hours before the Sun.

  • Astronomy Class: The Stargazer's four-session "Learning the Night Sky" class will be Aug. 2-5, 8-10 p.m. The cost is $25 per person with family discounts and scholarships available. Call or email for information or to register.

  • Astro Milestones: July 20 is the 35th anniversary of astronauts Neal Armstrong and Buzz Aldrin's 1969 lunar landing.


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July 3, 2004

Early Evening Shows Feature Two Planets and a Star Cluster

This week Mars, Mercury and the Beehive star cluster will put on great shows shortly after sunset. Each planet will pass through the cluster, then they will pass very close to one another.

Mars is not the brilliant red jewel it was this time last year when it was unusually near Earth and outshone all the stars. Now it shines only as brightly as Polaris, the North Star.

Mercury does outshine all but the brightest stars, yet most folks have never seen it. Since it orbits nearest the Sun, it never appears far from the Sun and is often too near the Sun to be seen. When it is visible it is seen only low in the east shortly before sunrise or low in the west shortly after sunset.

The Beehive star cluster is a beautiful swarm of 200 stars in the constellation Cancer the Crab and located 515 light years away. This distance, vast in Earth terms, is close cosmically-speaking, making the Beehive a nearby neighbor in our Milky Way galaxy.

Stars form in clusters before eventually drifting apart, so these are young stars--400 million years old, compared to our 5 billion-year-old Sun--still grouped with their birthmates. Under dark skies naked eyes see the Beehive (also called M44 and Praesepe) as a soft, fuzzy patch of light about the size of a full Moon. However binoculars--even small ones--show dozens of individual stars.

Tomorrow and Monday Mars passes through the Beehive, looking like a bright reddish cluster member. By Wednesday Mars will have moved to the cluster's upper left while Mercury will be to its lower right, all appearing in the same binocular field of view. Then Thursday, it will be Mercury's turn to pass through the cluster with Mars further to their upper left.

Seeing these shows will require good timing and a location with a view down to the western horizon. Using binoculars, begin looking less than 10 degrees above the western horizon 40-45 minutes after sunset (about 9:20 in Central Texas). (The width of your fist held at arm's length is 10 degrees.)

If you watch over several days, you'll notice the two planets closing in on each other. July 10 they will pass within 1/6 of a degree (1/3 the width of a full Moon) with brighter Mercury above Mars. The Beehive will be less than 4 degrees to their lower right. The show should be great in binoculars and telescopes.

  • Next Two Weeks: Average sunrise: 6:31 a.m.; average sunset: 8:36 p.m. (for Waco,TX)
    * Monday morning (July 5) Venus passes near Taurus' brightest star, Aldebaran, and appears to be a bright member of the Hyades star cluster.
    * Monday (July 5) Earth reaches aphelion, the point in its elliptical orbit where it is farthest (94.4 million miles) from the Sun.
    * The Moon is at 3rd quarter Friday (July 9).
    * The morning of July 12 a crescent Moon will be to the left of the Pleiades star cluster, and the next morning to the upper left of Venus and Aldebaran low in the east.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Mercury and Mars set a little more than an hour after the Sun while Jupiter, the brightest starlike object higher in the west, sets at midnight. Morning: Venus rises 2 hours before the Sun and is the beautiful "morning star" the rest of 2004. Saturn, now too near the Sun to be seen, soon moves into the morning sky.


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June 19, 2004

Cassini-Huygens Mission to Saturn: Part II

The Cassini-Huygens mission, launched in October 1997, is nearing its destination, the planet Saturn. As its name suggests, it is actually two spacecraft with separate missions. The larger Cassini will orbit Saturn while the smaller Huygens, now riding piggy-back on Cassini, will separate and land on Saturn's moon Titan.

Each spacecraft has cameras to provide us with breathtakingly closeup pictures of Saturn, its rings and many of its moons. And both are loaded with scientific instruments--12 on Cassini and 6 on Huygens--to carry out the scientific work of measuring things and sending back numbers for scientists to analyze. (That's what scientists do--measure things, analyze the results and come up with explanations of how our cosmos and the things in it work.)

The Cassini mission is scheduled to last at least 4 years, and NASA hopes to extend the mission up to another 4 years if the equipment and power sources hold out. While orbiting Saturn its instruments will yield data about Saturn's composition and structure, its magnetosphere, its moons and fascinating rings. With this information, scientists expect to gain a better understanding of the formation and evolution of our 5 billion-year-old solar system. And in so doing, perhaps they will learn more about the development of other solar systems in our galaxy and in the countless other galaxies throughout the cosmos.

Of Cassini-Huygens' many scientific endeavors, none holds more promise of yielding dramatic new knowledge than the Huygens mission. After separating from Cassini on Dec. 24, Huygens will land on Saturn's largest moon Titan in mid January 2005, returning images and data about this strange world.

Although much colder than Earth, Titan--which is larger than the planets Pluto and Mercury--has an atmosphere curiously similar to ours. If it is found to resemble a prebiotic Earth, it could offer more clues toward solving one of the most intriguing and profound mysteries--how life developed on Earth, and perhaps beyond.

  • Next Two Weeks. Average sunrise: 6:25 a.m.; average sunset: 8:37 p.m. (Waco, TX)
    * Early this evening the crescent Moon is to the lower left of Gemini's brightest star, Pollux, and to the right of fainter Mars.
    * Tomorrow is the Northern Hemisphere's summer solstice, the first day of summer and the year's longest day.
    * Tomorrow evening the crescent Moon is above Mars and to the right of the Beehive star cluster.
    * Tuesday evening the Moon is to the upper right of Leo's brightest star, Regulus, and the next evening to Jupiter's upper right.
    * The Moon is at 1st quarter Friday.
    * The evening of June 26 the Moon is above Virgo's brightest star, Spica.
    * The evening of June 29 the Moon is to the upper right of Scorpius' brightest star, Antares.
    * July 2, 1 a.m. CDT is the midpoint of 2004.
    * The July 2 full Moon is called the Thunder Moon and Hay Moon.

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Saturn, very low in the west northwest, sets an hour after the Sun with much fainter Mars setting an hour later. Jupiter, the brightest starlike object in the southwest, sets soon after midnight. Morning: After many months as the beautiful "evening star," Venus is about to become the "morning star" for the rest of 2004.


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June 5, 2004

Cassini-Huygens Mission to Saturn

Do you have an acquaintance you've known all your life yet who, in one relatively short period of time, you got to know much better than you ever imagined?

If things go as planned, that's about to happen with Saturn, the ringed planet we've known all our lives. The Cassini-Huygens spacecraft, launched in 1997, is due to arrive at Saturn July 1 and begin an up-close multiyear study of the planet, its famous rings and several of its 31 (at present count) moons.

Our ancestors knew of Saturn before recorded history, although they considered it a "wandering star" along with Mercury, Venus, Mars and Jupiter. Eventually they realized these wanderers were different from and nearer than the "fixed" stars, and began calling them planets.

With the newly invented telescope Galileo Galilei (1564-1642) discovered that Saturn seemed to have "handles." A few decades later and working with better telescopes, Christiaan Huygens (1629-1695) correctly hypothesized that the handles were rings. His contemporary, Jean-Dominique Cassini (1625-1712), suggested that the rings were composed of countless small particles, and he also discovered the large, seemingly empty gap in the rings, now known as the Cassini Division.

Since the advent of the Space Age in the last half-century we have come to know Saturn better, especially from images and data returned by the 1979-81 Voyager 1 and 2 flybys. But at nearly a billion miles away, Saturn remains a stranger in many ways. Within the next few weeks, we should start getting to know Saturn and its satellites like never before.

While the main show begins July 1, we'll get a sneak preview June 11 when Cassini-Huygens passes 1,240 miles from Saturn's tiny moon Phoebe. Watch the news for great images to whet your appetite for more to come. More on Cassini-Huygens next time.

  • Next Two Weeks. Average sunrise: 6:23 a.m.; average sunset: 8:34 p.m. (Waco, TX)
    * Tuesday morning Venus transits (passes across the face of) the Sun, but unfortunately for us all but the last few minutes of the 6-hour event occur before sunrise. (Venus transits are rare, the next one being in 2012, so watch for tv coverage.)
    * The Moon is at 3rd quarter Wednesday.
    * Friday Pluto is at opposition, making this the best time of year to look for the extremely faint, farthest and smallest planet. However at 14th magnitude. Pluto won't show in most amateur scopes. (Even though its discoverer Clyde Tombaugh is one of my heroes, I've never seen the planet he discovered.)
    * The early evening of June 12 Mars is to the left of Gemini's twin stars, Pollux and Castor, looking like the twins have a fainter brother.
    * The crescent Moon is to the lower right of the Pleiades star cluster low in the east the morning of June 15.
    * The Moon is new June 17.

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Saturn is low in the west and sets 2 hours after the Sun. Fainter Mars is to Saturn's upper left, setting 30 minutes later. Jupiter, the brightest starlike object high in the southwest, sets after midnight. Morning: Mercury can barely be seen near the east northeastern horizon as dawn breaks but is sinking nearer the Sun each morning. Venus, which has been the lovely "evening star" for the past several months, is in the Sun but will soon emerge as the "morning star" for the rest of 2004.


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May 22, 2004

Circumpolar Region: Where the Stars Never Rise or Set

There's a place in the sky where the stars never rise or set, an area called the Circumpolar Region. Here the same stars are up all night, every night of the year, although their positions do change throughout the night and year.

The Circumpolar Region is created by the daily rotation of Earth on its axis, making it look like the night sky revolves around one point every 24 hours. Called the celestial north pole, that point is straight above Earth's rotational north pole.

By chance a reasonably bright star happens to be very near the celestial north pole. That star, Polaris (also named the North Star), is fixed and never moves in our sky. (Actually Polaris is slightly off true north and moves just a tad, but for most purposes we can think of Polaris as fixed and unmoving.)

As Earth rotates west-to-east, it makes the stars seem to move counterclockwise around Polaris, like hands of a clock moving backwards. While stars farther from Polaris spend part of the time below the horizon, those nearer the pole star simply circle it, never dipping below the horizon.

Ignoring the slight deviation, Polaris' distance above the horizon always equals the latitude from which it is viewed, so the size of the Circumpolar Region depends upon the viewer's latitude. For example, from a location at latitude 31 degrees North, Polaris is always 31 degrees above the horizon, and at the center of a Circumpolar Region 62 degrees in diameter.

The extreme situation exists at the North Pole (latitude 90 degrees North) where Polaris is always straight up, 90 degrees above the horizon. There the Circumpolar Region includes the entire sky with no star ever dipping below the horizon.

From most of Texas all or part of six constellations are within the Circumpolar Region: Ursa Major the Big Bear, Ursa Minor the Little Bear, Queen Cassiopeia, King Cepheus, Draco the Dragon and Camelopardalis the Giraffe. Ursa Major includes the well known Big Dipper, so every night of the year at least part of this familiar pattern can be seen. When at its lowest point below Polaris, some Big Dipper stars slip below the northern horizon for a few hours, but parts of the Dipper never leave our sky.

  • Next Two Weeks: Average sunrise: 6:25 a.m.; average sunset: 8:27 p.m. (for Waco, TX) * Early this evening look in the west for the crescent Moon above Mars and Saturn with brilliant Venus beneath them. * Monday evening Mars passes nearest and to the upper right of brighter Saturn. * Thursday evening the 1st quarter Moon is above Jupiter. * The June 2 full Moon, called the Rose Moon, Flower Moon and Strawberry Moon, is to the left of Scorpius' brightest star, Antares. (Seems like the full Moon of June should be called the Honey Moon!)

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Morning: Mercury, rising just an hour before the Sun, is very low in the east as dawn breaks. Evening: Nearing the end of its stint as this year's "evening star," Venus will be low in the west soon after sunset for another week or so. Mars and nearby Saturn set shortly after 11 p.m. with Jupiter up until 2:30 a.m.

  • Comets Update. Comet LINEAR is now joining Comet NEAT in the evening sky. LINEAR is low in the west southwest soon after dark while NEAR is up most of the evening high in the west. Seeing both requires binoculars.


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May 8, 2004

Updates on Comets NEAT and LINEAR

The awaited Comets NEAT and LINEAR are here, and while neither is a show stopper, they are still worth a look.

A week ago Comet LINEAR was binocular-visible low in the east as dawn was breaking, but is now too near the Sun for viewing. It comes nearest Earth and will be at it brightest May 19, but unfortunately will still out of our view.

It will re-emerge in the evening in late May, by which time it will have dimmed notably. It should again be visible in binoculars low in the west southwest as the skies darken.

Comet NEAT promises a better show. Now at its brightest in the evening sky, it is visible for two hours after dark, and should be visible with naked eyes, perhaps from within cities, but certainly from darker rural skies.

It is now passing near the bright star, Procyon, which at 9:45 p.m. is 30 degrees above the western horizon. (The width of your fist held at arm's length is 10 degrees, and don't confuse Procyon with the brighter planets Venus and Saturn further west.)

Tonight NEAT is 12 degrees to Procyon's lower left. Climbing higher each night, it is 8 degrees to the star's left tomorrow, 6 degrees to its upper left Monday, and 9 degrees above it Tuesday.

The evenings of May 14 and 15 Comet NEAT passes the lovely Beehive star cluster. It is 2+ degrees below the Beehive May 14, then a mere 1 degree (2 moonwidths) to its upper right the next night. An hour and a half after sunset the Beehive is 45 degrees above the western horizon. Under dark skies it appears to naked eyes as a soft, faint patch of light the size of a full Moon, but binoculars show it to be a beautiful swarm of dozens of stars. The comet will be smaller than the cluster, but about the same overall brightness. They should be especially dazzling in binoculars with both in the same field of view.

For the next several weeks Comet NEAT will climb higher and grow fainter each night. From the end of May through the end of July it is likely to be visible only in binoculars, and after that only in telescopes.

  • Next Two Weeks: Average sunrise: 6:31 a.m.; average sunset: 8:18 p.m. (for Waco, TX) For the next several nights Mars is quite close to M35, a binocular open star cluster in Gemini. Monday evening Venus, Mars and Saturn are evenly spaced on a diagonal low in the west with brightest Venus to the lower right, least-bright Mars in the middle and Saturn to the upper left. The Moon is at 3rd quarter Tuesday. The morning of May 16 the crescent Moon is to the upper right of Mercury low in the east just before dawn. The Moon is new May 18. The evening of May 20 the crescent Moon is below the "evening star," Venus, then the next night above the beautiful planet.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Venus is still the blazing "evening star" in the west but begins rapidly receding toward the Sun and is nearly gone from the evening sky by month's end. Much fainter Mars, also in the west, sets a little before midnight. Just to Mars' upper left is brighter Saturn which is also down by midnight. Jupiter, the brightest starlike object in the southwest, sets around 2 a.m. Morning: Mercury, rising an hour before the Sun, is low in the east as dawn begins to break.


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April 24, 2004

Comets NEAT and LINEAR

Two comets are coming our way, and one or both could get interesting. Comets NEAT and LINEAR were discovered by automated sky-survey programs that look for and track near-Earth asteroids.

In 2001 the Near-Earth Asteroid Tracking program with telescopes in California and Hawaii found Comet C/2001 Q4 (Comet NEAT), and in 2002 the Lincoln Near-Earth Asteroid Research program using two New Mexico telescopes discovered Comet C/2002 T7 (Comet LINEAR).

Astronomers predict that both will be naked-eye comets (but not like Comet Hyakutake in 1996 or Hale-Bopp in 1997). Comet LINEAR might become the brighter of the two, but Comet NEAT is better positioned for Northern Hemisphere viewing.

Comet LINEAR is now visible in the morning low above the eastern horizon just before dawn. Using binoculars, look for a fuzzy starlike object with a wisp of a tail pointing upward away from the rising Sun. Reaching its highest (but still quite low) around May 1, LINEAR will then sink toward the Sun. It comes closest to Earth and should be at its brightest May 19, but unfortunately will then be out of our view. We'll see it again when it appears in our evening sky in late May, but by then it will have dimmed notably.

Comet NEAT promises a better show and all in the evening. The first few days of May it will appear above the southwestern horizon after dusk, climbing northward and eventually passing through the Big Dipper in mid summer. It will be at its brightest around May 5-10 when it passes nearest Earth.

NEAT will be in the constellation Canis Major May 4-6, passing left of the night sky's brightest star, Sirius, May 5. May 6 and 7 it can be seen within the same binocular view with two star clusters (M46 and M47). On May 9 and 10, it will pass to the left of another bright star, Procyon.

NEAT's dust tail will be pointed to the upper left away from the Sun. Although the comet should be visible to naked eyes, it might be easier to find it first with binoculars.

  • Next Two Weeks. Average sunrise: 6:43 a.m.; average sunset: 8:08 p.m. (for Waco, TX)
    * Tonight (Apr. 24) the Moon is to the right of Saturn.
    * Venus and Mars, spending several nights just a few degrees apart, are at their closest tomorrow (Apr. 25) evening.
    * The Moon is at 1st quarter Tuesday (Apr. 27), then just above Jupiter Thursday (Apr. 29) evening.
    * May 1 is May Day, also known as Beltane, a cross-quarter day celebrating the middle of spring.
    * Venus, at its brightest for the year on May 2, passes near the star El Nath the evening of May 3.
    * The May 4 full Moon, called the Planting Moon and the Milk Moon, will feature a total lunar eclipse which unfortunately will not be visible from the U.S.
    * In the early evenings of May, the Milky Way seems to vanish from the night sky as it lies flat around the horizon.

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: "Evening star" Venus is the brightest starlike object in the west with much fainter reddish Mars a bit to its upper left. Both set before midnight. Saturn is further up to the upper left and sets after midnight. Jupiter, the brightest starlike object in the southeast, sets about 4 a.m. Morning: Mercury is gradually climbing out of the morning Sun and will soon be just above the eastern horizon shortly before sunrise.


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April 10, 2004

Planets in the Evening Sky

The four best-known naked eye planets -- Venus, Mars, Saturn and Jupiter -- are still in the evening sky and will be for the next couple of months. Here's where to find them about 9:30 p.m.

Venus is the brightest object 24 degrees above the western horizon. (The width of your fist held at arm's length is 10 degrees.) The "evening star" for the past several months, Venus will dominate the western sky until early June. Other than the Sun, Moon and an occasional fireball meteor, Venus outshines all other natural objects, including the stars. Like our Moon, Venus goes through phases, and now looks like a tiny quarter moon in telescopes. Now in Taurus the Bull, Venus sets around 11:30 p.m.

Mars, also in Taurus, is 7 degrees to the upper left of Venus, but not nearly as bright. In contrast to its dramatic appearance last year, Mars is now much smaller, fainter and less interesting in telescopes.

Mars and Venus form a triangle with Taurus' brightest star, Aldebaran, which is 10 degrees to Venus' left. Aldebaran and Mars, both reddish in color, look similar although the star now outshines the planet. Mars goes down around midnight.

Saturn, looking like a bright creamy-colored star, is 24 degrees to the upper left of Mars. At public star parties telescopic views of Saturn and its rings draw more "oohs" and "aahs" than any other object. Less obvious yet visible in amateur telescopes are several of Saturn's moons. Situated in Gemini the Twins, Saturn sets at 1:45 a.m.

The largest planet, Jupiter, is 60 degrees above the horizon in the southeast. Now in Leo the Lion it far outshines surrounding stars and is second in brightness only to Venus. Telescopes easily show its four largest moons, called the Galilean moons in honor of Galileo who discovered them in 1609. Jupiter is up until 5:30 a.m.

Mercury can also still be seen low in the west just after sunset, but just barely as it sets 45 minutes after the Sun.

The three outermost planets--Uranus, Neptune and Pluto--are now in the morning sky, and all require optical aids to see. Pluto, the smallest and most distant, is too faint for all but the largest amateur telescopes. Even though Pluto's discoverer, Clyde Tombaugh, is one of my heroes, I, like most stargazers, have never seen the tiny, faraway world. Being the only planet never visited by a space craft, it remains a mystery planet about which we still have much to learn.

  • Next Two Weeks: Average sunrise: 6:58 a.m.; average sunset: 7:59 p.m. (for Waco, TX) * The Moon is at 3rd quarter tomorrow (Apr. 11). * The Apr. 19 new Moon will partially eclipse the Sun, but it will not be visible from the U.S. * The early evening of Apr. 21 the thin crescent Moon is to the lower left of the Pleiades star cluster low in the west soon after sunset, and below Venus the next evening. * The Lyrid meteor shower peaks the night of Apr. 21/22 with the best chance of seeing meteors coming between midnight and dawn; moonlight will not interfere this year. * The evening of Apr. 23 Mars comes within 4 degrees of an equally bright star, El Nath, with the crescent Moon between them; Venus is to their lower right and Saturn further to their upper left.

  • Astro Milestones: Apr. 12 is the 43th anniversary of Russian Cosmonaut Yuri Gagarin's 1961 historic 108 minute orbital flight around Earth, making him the first human to orbit Earth.


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MARCH 27, 2004

Nature's Game

Suppose you awoke to find yourself in the middle of an ongoing game. You had no choice about playing, but no one told you the rules--you had to learn them as you played. That was pretty much the early human predicament, and still is to some extent.

Think of nature as a game. Just as games have rules, nature has rules we call laws of nature. As humans began to evolve thousands of years ago, we found ourselves in the middle of nature's game which had been going on long before we arrived.

We came into the game with a huge disadvantage: we weren't told the rules. We didn't know much about the game but we still had to play just to survive. And not knowing the rules, we have had to deal with many hardships such as sickness, hunger, harsh elements, fear, violence and short lives.

But we also had some advantages. We were well adapted to Earth's conditions, had mobility, good manual dexterity and senses. And now our intelligence and civilization have evolved so that we have begun to figure out nature's rules by noticing patterns.

And that's what science and the scientific method are about. Once we learned that nature's laws are immutable--that nature doesn't violate its laws--scientists began systematically looking for patterns and discovering nature's laws.

Before our ancestors knew many of the laws of nature, they felt at nature's mercy. Not knowing what else to do, they often turned to magical and superstitious thinking. Perhaps thinking a storm was caused by an angry storm god, they may have offered a sacrifice to try to make the storm god happy.

Even today, many still engage in magical thinking. Some, for example, read horoscopes and believe in astrology, the ancient system of superstition which holds that the positions of planets and stars affect human affairs. As pointed out by Carl Sagan and many other scientists, astrology doesn't hold up under scientific scrutiny--it simply has no rational or verifiable basis.

Experience has taught us that the more we rely on our intellect than on superstition, the better we get at mastering nature's laws, enabling us to make life better for more of humanity. But since we haven't learned everything, we still need science and scientists, and probably always will. And since we don't always wisely use what we do know, we still need philosophers, artists, teachers, statesmen and dreamers, and probably always will.

  • Next Two Weeks: Average sunrise: 6:15 a.m. CST; average sunset: 6:49 p.m. CST. (for Waco, TX) * Tomorrow (Mar. 28) evening's 1st quarter Moon is to the upper left of Saturn in the southwest. * The Moon is to the lower left of Jupiter Friday (Apr. 2) evening. * The evenings of Apr. 2-4, Venus passes by the edge of the Pleiades star cluster. * The April 5 full Moon, called Grass Moon, Egg Moon and Pink Moon, is to the lower left of Virgo's brightest star, Spica. * The evening of Apr. 5, Mars passes to the right of Taurus' brightest star, Aldebaran. * The morning of Apr. 9 the Moon is to the left of Scorpius' brightest star, Antares. * The evening of Apr. 9 Venus, Mars and Aldebaran form a triangle with Mars at the top, Venus to the lower right and Aldebaran to the lower left.

  • Planets: (The Sun, Moon and planets all rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Venus and Mercury are at their highest above the setting Sun with Mercury setting 1 1/2 hour after the Sun and Venus setting 2 hours later. Mars sets after 11 p.m. Saturn, high in the south in the evening, sets at 1:30 a.m. Jupiter, in the east in the evening, sets before sunrise.

  • Astronomy Class: The Stargazer's 5-session "Learning the Night Sky" class is April 5, 6, 12, 13 & 14 from 8-10 p.m. The cost is $25 per person with family discounts and scholarships available. Call or email for information or to register.

  • Eclipse Countdown: It's now only 20 years until the Apr. 8, 2024 total solar eclipse passes over the heart of Texas.


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March 13, 2004

Moon's Guided Tour of the Planets

With so many stars, it can be hard to pick out the planets, and right now all five naked eye planets are in the evening sky. Beginning Mar. 22 the Moon can be your personal guide, helping you identify each naked eye planet.

After the Moon is new on Mar. 20, it moves into the evening sky as a waxing crescent, climbing higher and growing more illuminated each evening.

The early evening of Mar. 22, a barely-visible thin crescent Moon will point out the elusive planet Mercury. About 45 minutes after sunset, the Moon is 13 degrees above the horizon in the west with Mercury to the Moon's lower right, half way to the horizon. (The width of your fist held at arm's length is 10 degrees.) You'll need a location with a clear view of the western horizon, and binoculars will help. Mercury sets 1 hour and 20 minutes after the Sun, so don't wait too long.

The evening of Mar. 24 displays one of the night sky's most striking views when the crescent Moon is just 2 degrees (4 moonwidths) to the left of blazing Venus.

The next evening it is even closer to Mars when it passes within 1 degree (less than 2 moonwidths) to the right of the red planet. Mars is not nearly as bright as it was last summer and fall, but it's still brighter than most stars.

As an extra treat, the Moon-Mars duo will be just 4 degrees to the upper left of the Pleiades star cluster (also known as the Seven Sisters), and 10 degrees to the lower right of Taurus' brightest star, Aldebaran, and the V-shaped Hyades star cluster. That grouping, along with Venus below them, will make this the one evening you won't want to miss.

The evening of Mar. 28, the 1st quarter Moon is 5 degrees above Saturn. Although Saturn is brighter than most stars, the glare of the Moon will almost overpower it.

Finally on Apr. 2, a large gibbous Moon, making the last stop on its guided planetary tour, is 4 degrees to the lower left of Jupiter. Although the Moon will be quite bright, Jupiter, brighter than any star, will hold its own against the moonlight.

  • Next Two Weeks: Average sunrise: 6:33 a.m.; average sunset: 6:40 p.m. (for Waco, TX) * The Moon is at 3rd quarter tonight and new March 20. * March 20 at 12:49 a.m. is the beginning of spring (vernal equinox) in the Northern Hemisphere. * The evening of March 20 Mars passes just to the lower left of the Pleiades.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation.) Mercury sets less than an hour after sunset. Venus, the "evening star," sets over 3 hours after the Sun. Mars, looking like a fairly bright reddish star 16 degrees above Venus in the west, sets just after 11 p.m. Saturn, high in the southwest in the evening, sets at 1:30 a.m. Jupiter is up all night--in the east in the evening and low in the west before dawn.

  • Astronomy Class: The Stargazer's 5-session "Learning the Night Sky" class will be April 5, 6, 12, 13 & 14 from 8-10 p.m. The cost is $25 per person with family discounts and scholarships available. Call or email for information or to register.

  • Astro Milestones: Mar. 13 is the 223rd anniversary of William Herschel's discovery of the planet Uranus in 1781 from Bath, England.


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Feb. 28, 2004

Leap Day and Nature's Imperfections

We humans seem more comfortable when things come out even and meet our ideas of perfection. But either Mother Nature doesn't have the same need, or she doesn't share our views of perfection.

In the 1600s when Galileo tried to convince the world that Copernicus' Sun-centered theory of the cosmos was correct, his ideas of perfection got in his way. Believing that nature deals only in perfections, he got hung up on the idea that planets should orbit the Sun in perfect circles, and this made predictions about where planets should be come out wrong.

It took Kepler's thinking-outside-the-box discovery that planetary orbits are imperfect circles (called ellipses) to make the theory's predictions come out right.

Galileo's assumption about nature's perfection blinded him to newer insights into how nature works. We are about to experience another of nature's imperfections as our 2004 calendar adds Feb. 29.

We define a day as the time it takes Earth to make one rotation on his axis. (Partitioning this into hours, minutes and seconds is an arbitrary human creation.) We define a year as the time it takes Earth to make one revolution around the Sun.

If Mother Nature shared our conception of perfection, surely things would have come out even--like a 360-day year. With twelve 30-day months, that would have been so neat and tidy, but, alas, she didn't. A year is 365.2422 days. So untidy.

So we add Feb. 29 to our calendar every fourth year in years divisible by four. This gets us closer, but 365.25 days over-corrects by 11 minutes per year. In a mere 23,000 years our calendars and seasons would be so out of sync we'd have summer in December and winter in June. We can't have that, so we adjust some more. Omitting Leap Year in century years (thus there was no Feb. 29, 1900) gets us even closer, but slightly under-corrects. So we DO have Leap Days in century years divisible by 4, which is why we had a Feb. 29, 2000.

All this makes perfectly good sense, except why Feb. 29? Why not make Leap Day Dec. 32 and declare it a universal holiday? Now there's a good issue for politicians to campaign on.

  • Next Two Weeks: Average sunrise: 6:50 a.m.; average sunset: 6:30 p.m. (Waco, TX) * Monday evening the large gibbous Moon is to the upper left of Saturn. * The March 6 full Moon, called Crow Moon, Sap Moon and Lenten Moon, is to the lower left of Jupiter.

  • Planets: (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Venus, still the brilliant "evening star," sets more than 3 1/2 hours after sunset. Mars looks like a fairly bright reddish star 17 degrees above Venus. (The width of your fist held at arm's length is 10 degrees.) The two, moving slightly nearer each other each night, will be at their closest in late April. Saturn is high in the southwest in the early evening and sets after midnight. Jupiter now appears as bright and large as we'll see it all year. Mar. 3, when it comes opposite the Sun as seen from Earth (called opposition), it rises as the Sun goes down, is high in the south at midnight and sets at sunrise. Mercury is too near the Sun for viewing.

  • Astro Milestones: March 8 is the 25th anniversary of Voyager 1's 1979 discovery of active volcanoes on Jupiter's moon Io, the first evidence of such geologic activity beyond Earth.


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February 14, 2004

Copernicus, the Scientific Revolutionary

Feb. 19 is the 531th birthday of Nicolaus Copernicus (1473-1543). Without firing a shot, he launched one of history's most earthshaking revolutions--the scientific revolution--by asserting that the Sun, not the Earth, was at the center of the cosmos.

Not only did this radical idea run counter to prevailing scholarly views, the Roman Catholic Church (the de facto government in those days) regarded his idea as a heresy undermining the foundations of the Christian religion. Knowing the danger of offending the Church--which imprisoned and even burned-at-the-stake people who disagreed with it--Copernicus had the good sense to have his major work published after his death.

When we think of revolutionary leaders, we often envision brash, single-minded zealots leading like-minded comrades in battle. But such a description just doesn't fit Copernicus.

Born in Poland into a comfortable and influential family, and university educated in Poland and Italy, Copernicus was a quiet and reserved individual who was also an intelligent and questioning thinker. He was certainly not one-dimensional.

Best known as an astronomer, this truly renaissance-man was also a respected physician and a lawyer. And when his homeland was invaded, he became a political and military commander coordinating Polish soldiers in resistance and defense.

During his early university days he became increasingly skeptical about the Earth-centered view of the cosmos. In 1507, at age 34, he wrote a short book setting forth the essence of what would come to be known as the Copernican theory. But the book was never printed and didn't become widely circulated.

While attending to his duties as a physician and legal adviser, he still found time to carry out his astronomical studies. While he was not known as a skilled astronomical observer, he was a keen "noticer" of the world and the heavens. Living prior to the invention of the telescope or the scientific method, he arrived at his theory more from reasoning than scientific observations.

In 1533, at age 60, he completed his major work, On the Revolutions of Celestial Orbs, in which he set forth his arguments. But fearing the Church and its ruthless Inquisition, he withheld it from print. Finally, in early 1543, just months before the end of his life, he arranged for its publication, but died before ever seeing it.

It's also unlikely this reserved Pole ever imagined he would come to be revered as the instigator of one of history's most profound intellectual revolutions.

  • Next Two Weeks: Average sunrise: 7:04 a.m.; average sunset: 6:20 p.m. (Waco, TX) * The Moon is new Friday. * The crescent Moon is near Venus the evening of Feb. 23, then passes even nearer to Mars Feb. 25. * The 1st quarter Moon on Feb. 27 is between Taurus' brightest star, Aldebaran, and the Pleiades star cluster.

  • Planets: Venus, the "evening star," sets 3 hours after sunset. Higher in the west, Mars sets just before midnight. Saturn, high in the southeast, goes down at 4:30 a.m. Jupiter rises in the early evening and is the "morning star" in the west.

  • Astro Milestones: "Dr. Slipher, I've found your Planet X." So announced 24-year old American astronomer Clyde Tombaugh on Feb. 18, 1930, after discovering from Lowell Observatory near Flagstaff, AZ, the planet that would be named Pluto. Tombaugh is the only American to discover a planet.


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January 31, 2004

What We See in the Night Sky

On a clear moonless night far from city lights, gazing into the sky can be exhilarating and awe-inspiring. The vastness of the sky makes it seem like we're looking at millions of stars and seeing to the edge of the cosmos, but both of these impressions are wrong. So what and how far can we see with our naked eyes?

The brightest things we see are solar system neighbors--the Moon, planets, meteors and comets. Beyond that we see stars (which are other Suns), star clusters, nebulae and galaxies.

At the largest scale, the cosmos is composed of galaxies--many billions of them widely separated from each other, mostly by empty space. Each galaxy, like our own Milky Way galaxy, contains stars (many millions to many billions depending upon the galaxy's size), star clusters and nebulae. Most stars, like our Sun, exist as single entities orbiting the center of the galaxy while some are in close groupings called clusters. Nebulae are cosmic clouds of dust and gasses, some generating new stars and some being the remains of dead stars.

Most of what we see, of course, are individual stars--but not millions, only a couple of thousand at most. And the ones we see are in our immediate part of our galaxy. In addition we can see a few dozen star clusters, a few nebulae, and a couple of nearby galaxies, and that's it. Without binoculars or telescopes we just don't see millions of stars or deep into the cosmos.

An analogy is helpful. If Earth is the cosmos, the towns and cities are galaxies, apartments are clusters, and houses are stars. (The analogy assumes you live in a town or city.)

From your house (star), you probably can't see other towns (galaxies) unless you live on a hill, and then likely only one or two nearby ones. You might see a few apartments (clusters) but mostly you see the other houses (stars) in your own neighborhood. Even though there are thousands of other towns, and millions of other houses, you can't see them from your house.

So we actually see less than it seems, but that doesn't have to diminish the exhilaration and awe we sense when we look into the beautiful night sky.

  • Next Two Weeks. Average sunrise: 7:17 a.m.; average sunset: 6:09 p.m. (for Waco, TX) * Monday is Candlemas and Groundhog Day, a cross-quarter day celebrating the middle of winter. * Monday evening the Moon is to the upper left of Saturn. * Friday's full Moon of January is called Snow Moon, Hunger Moon and Wolf Moon. * The Moon is at 3rd quarter Feb. 13 which is also Friday the 13th, a day considered unlucky by many in the U.S. While superstitious tendencies seem universal, specifics vary as other cultures hold other days and dates as unlucky. (To the superstitious: Beware--there will be another one in August.)

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) EVENING: Venus, the blazing "evening star" in the west, sets 3 hours after sunset. Mars, looking like a bright, slightly reddish star high in the southwest, sets around midnight. Saturn is up most of the night, appearing high in the east in the evening and down by 5 a.m. MORNING: Mercury starts this period rising an hour before the morning Sun but quickly sinks into the rising Sun. Jupiter rises less than 3 hours after sunset and is the bright "morning star" shining in the west.

  • Astro Milestones: Feb. 3 is the 98th anniversary of the birth of American astronomer Clyde Tombaugh (1906-1997) who discovered the planet Pluto in 1930.


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January 17, 2004

Seeing Mercury in the Morning

This is a good time for morning stargazers to see the elusive planet Mercury, a world more like our Moon than our own planet. Now rising an hour and a half before the Sun, it is nearly 10 degrees above the southeastern horizon 45 minutes before sunrise. (The width of your fist held at arm's length is 10 degrees.)

You'll need a place with a clear view down to the southeastern horizon, and binoculars might help. It will be the brightest object in the area, brighter even than Scorpius' brightest star, Antares, 30 degrees to its upper right. Don't confuse Mercury with the star, Altair, near the horizon in the east.

The planet nearest the Sun, Mercury never appears far from the Sun and is only seen just before sunrise or just after sunset.

Although it comes within 60 million miles of us every 4 months (only Venus and Mars come nearer), we have not explored Mercury extensively. To date only Mariner 10 in 1974-75 has provided us with close-up photos and other data about our small neighbor. That will change when later this year we launch MESSENGER, due to reach and begin orbiting Mercury in 2009.

Mercury is not a place for astronauts. Being so near the Sun, its daytime temperatures range from 400-800 degrees, and with no atmosphere to hold warmth, nighttime temperatures plunge to nearly 400 degrees below zero.

The second smallest planet, larger only than distant Pluto, Mercury's diameter is 1/3 that of Earth's. A bit larger than our Moon, its surface looks very much like our Moon's with lava-flooded plains and extensive cratering. It may not be a place we'd want to visit, but it's still fun to see, so look for it.

  • Next Two Weeks: Average sunrise: 7:26 a.m.; average sunset: 5:56 p.m. (for Waco, TX) * Tomorrow morning the crescent Moon is to the lower left of Scorpius' brightest star, Antares, low in the southwest, and the next morning to the upper right of Mercury. * The Moon is new Wednesday. * The evening of Jan. 24, the crescent Moon is to the left of Venus in the southwest. * It is then near Mars higher in the southwest Jan. 27, and at 1st quarter Jan. 29.

  • Planets. (The Sun, Moon and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Venus is the beautiful "evening star" in the west setting 3 hours after the Sun. Mars, the brightest starlike object high in the southwest, sets around midnight. Saturn is in the sky nearly all night, seen in the east in the evening and low in the west in the morning. Morning: Mercury, gradually retreating from the morning sky, gets lost in the Sun by mid February. Jupiter rises around 10 p.m. and is seen high in the southwest in the morning.

  • New Telescope? The Central Texas Astronomical Society will host two free, public "Learn to Use Your New Telescope" sessions, indoor at the Waco-McLennan Co. Public Library (basement) Jan 22 and under-the-stars at Hewitt City Park Jan. 24, both 6:30-8:30 p.m. Bring your telescope for personal, hands-on assistance and instruction. For more information call Dick Campbell at 254-857-8310.

  • Column Anniversary: Having first appeared in the Waco Tribune-Herald Jan. 20, 1990, Stargazer begins its 15th year. Over the past two years, the column has been appearing in other Texas newspapers, now numbering around 30. Your continued readership, emails and comments are appreciated--keep 'em coming.


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January 3, 2004

Night Sky Highlights for 2004

Astronomically 2003 can be summed up in one word: Mars. The red planet was clearly the "star" of the year. While we don't expect a Mars-type show in 2004, we still anticipate a great year.

Few night sky objects hold the fascination of comets, and we might have a couple of good ones this spring. Comets C/2002 T7 LINEAR and C/2001 Q4 NEAT (even with their awkward names) are expected to be at least naked-eye visible and maybe quite bright.

The year will see two solar and two lunar eclipses, but only the Oct. 28 total eclipse of the Moon will be visible from here.

With the absence of interfering moonlight, this will be a good year for the Lyrid (Apr.), Delta Aquarid (July), Perseid (Aug.), Orionid (Oct.), Leonid (Nov.) and Geminid (Dec.) meteor showers. Of course, we can't predict clouds and meteor intensity.

Generally the 5 naked-eye planets will be in the evening sky during the first half of 2004 and in the morning sky the last half. They will have some interesting "close encounters" with other each other, some bright stars and some star clusters.

June 8 Venus will pass across the face of the Sun (called a transit), although this rare event won't be visible from the U.S. The morning of Dec. 7, we will (weather permitting) get to see the Moon pass in front of Jupiter (called a lunar occultation).

Finally, 2004 promises to yield new information about our solar system. If all goes well, 3 Mars landers--Britain's Beagle 2 and the U.S.'s rovers, Spirit and Opportunity--will greatly increase our understanding of the red planet. Cassini, launched in 1997, will reach Saturn in July and start exploring the ringed planet and its moon, Titan. Finally Sept. 8 Genesis, launched in 2001, will return solar particles to Earth for scientific study.

Locally, the Central Texas Astronomical Society's new Paul J. Meyer Observatory--located at the Turner Research Station near Clifton and featuring a 24-inch robotic research-grade telescope--is expected to be completed by mid-year.

  • Next Two Weeks. Average sunrise: 7:29 a.m.; average sunset: 5:44 p.m. (for Waco, TX) * Tomorrow Earth reaches perihelion, when it is nearest the Sun (91 million miles) in its elliptical orbit. * Tuesday evening the Moon is to the left of Saturn in the east. * Wednesday's full Moon is called Old Moon, Cold Moon and Moon After Yule. * The morning of Jan. 12 the Moon passes near Jupiter in the southwest. * The Moon is at 3rd quarter Jan. 14.

  • Planets. EVENING: Venus is the "evening star" low in the west. Mars is the brightest starlike object high in the southwest. Saturn is up all night--in the east in the evening, south at midnight, and west in morning. MORNING: Jupiter, the "morning star" in the southwest, rises before midnight. Mercury is low in the east before dawn the week before and after Jan. 17.

  • Stargazing Class. The Stargazer's "Learning the Night Sky" class will be held Jan. 7, 8, 12, 13 & 14 from 7:00 - 8:30 p.m. The cost is $25 with family discounts and scholarships available. Call or email for information or to register.

  • New Telescope? The Central Texas Astronomical Society will host 2 free, public "Learn to Use Your New Telescope" sessions, indoor at the Waco-McLennan Co. Public Library (basement) Jan 22 and "under-the-stars" at Hewitt City Park Jan. 24, both 6:30-8:30 p.m. Participants are invited to bring their telescopes for personal, hands-on assistance and instruction. For more information call Dick Campbell at 254-857-8310.


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 Copyright by Paul Derrick.  Permission is granted for free electronic distribution as long as this paragraph is included.  For permission to publish in any other form, please contact the author at pjderrick@aol.com