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STARGAZER COLUMNS: OTHER YEARS

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 paulderrickwaco@aol.com.

Stargazer Columns 2006

Dec. 30, 2006: So Who Is the Stargazer?
Dec. 16, 2006: The Sun Stands Still
Dec. 02, 2006: Names of Some Prominent Stars of Fall and Winter
Nov. 18, 2006: From Astrology to Astronomy
Nov. 04, 2006: Transit of Mercury
Oct. 21, 2006: Buying a Telescope
Oct. 07, 2006: SOFIA To Leave Waco
Sep. 23, 2006: Constellations from the Ancients
Sep. 09, 2006: Sadness At an Old Friend Slighted
Aug. 26, 2006: What's All the Buzz about Planets?
Aug. 12, 2006: Perseid Meteor Shower
Jul. 29, 2006: Space Exploration
Jul. 15, 2006: The Lure of the Stars
Jul. 1, 2006: The Wobble That Changes the Sky
Jun. 17, 2006: Moon's March through the Planets
Jun. 03, 2006: Beehive Still Abuzz with Activity
May 20, 2006: Mother Nature's End-of-Month Specials
May 06, 2006: Comet Schwassmann-Wachmann 3
Apr. 22, 2006: Jupiter At Opposition
Apr. 08, 2006: Using Venus to Find Uranus
Mar. 25, 2006: Solving Some Moon Mysteries
Mar. 11, 2006: You Only Think You're Sitting Still
Feb. 25, 2006: Looking for Zodiacal Light and Gegenschein
Feb. 11, 2006: Some Night Sky Coincidences
Jan. 28, 2006: Clyde Tombaugh Finally On His Way to Pluto
Jan. 14, 2006: Night Sky Highlights for 2006

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December 30, 2006

So Who Is the Stargazer?

Over the years I've answered countless questions about stars and stargazing via letters, emails, phone calls and at presentations, and I love it. And I get questions about me, people wanting to know, “Just who is the Stargazer?” And I don't mind answering that either.

I'm an amateur, not a professional astronomer. My degrees--BA, MSW and PhD from the University of Texas in Austin--are in sociology and social work. In 1998 I retired from my 35-year career as a social worker and college professor.

My interest in stargazing began as a teenager growing up on Galveston Bay near where NASA’s Johnson Space Center is now located. The then-dark skies and an 81-year old stargazer, Margaret Willits, lit the initial fire. The flame burned long enough for my parents to get me a telescope, but then smoldered for 30 years, only to be rekindled by Halley’s Comet in the mid-1980s. Since then it has burned with a vengeance.

Now virtually a full-time amateur astronomer, I spend my time writing, speaking and teaching, and, of course, stargazing when I can. This “career” began in 1990 when I began writing this every-other-week “Stargazer” column in the Waco Tribune-Herald. In 2002 it became more widely available, and now appears in some 40 papers.

My Stargazer Web site (www.stargazerpaul.com) was launched by a friend in 1998, then, once I got the hang of it, was taken over and expanded by me in 2002. My books, “A Beginner’s Guide to Learning the Night Sky” and “Stargazer’s Life List,” came out in 2003 and 2004.

Each year I conduct some 50 presentations, classes and sky tours, most for free, for children and adults. If you'd like to schedule a program for your group or class, see my Web site for information or contact me. I even do some traveling.

Basic biographical data: I was born in Houston in 1940, raised in Bayview, TX, lived 10 years in Austin and the last 38 years in Waco; my wife, Jane, and I married in 1962, and have two grown daughters and two grandchildren (who live next door).

And when I'm not stargazing? We are active in the Unitarian Universalist Fellowship of Waco, and I'm a folk musician who now plays for nursing homes rather than bars. And I love playing with my 6- and 9-year old neighbors!

Now that you know more about me, let me hear from you so I can get to know you better.

  • Next Two Weeks. Average sunrise: 7:23 a.m.; average sunset: 6:01 p.m. (for Waco, TX)
    * Jan. 3, Wednesday: January's full Moon is called Moon After Yule and Old Moon, and Earth is a perihelion, nearest the Sun in its elliptical orbit.
    * Jan. 5, Friday evening: The Moon and Saturn, up by 9 p.m., and travel across the sky together all night.
    * Jan. 6, Saturday evening: The Moon spends tonight even closer to the star Regulus.
    * Jan. 9, Tuesday morning: The year’s latest sunrise in Central Texas (7:29 a.m.), and Jupiter is to the left of Scorpius’ brightest star Antares as they rise in the southeast just before dawn.
    * Jan. 11, Thursday morning: The 3rd quarter Moon is to the right of Virgo’s bright star Spica high in the south before dawn.

  • 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.) Evening: Venus is emerging as the “evening star” low in southwest at dusk, and Saturn rises by 9:30 p.m. Morning: Saturn is high in the west with Jupiter, then Mars, rising before dawn.

  • Star Party. The Central Texas Astronomical Society hosts its free public star party at the Waco Wetlands Jan. 6 beginning at 7 p.m. For directions, see www.wacowater.com/wetlands.html.

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December 16, 2006

The Sun Stands Still

Perhaps you remember the sci-fi movie "The Day the Earth Stood Still." Well Dec. 21 will be "the day the Sun stands still," also known as the winter solstice and the Northern Hemisphere's shortest day of the year. (Things are reversed below the equator where it will be summer solstice and the year's longest day.)

Solstice literally means "sun-standing," thus twice each year at winter and summer solstice, the Sun stands still. But how can that be?

It's commonly known that the Sun rises in the east and sets in the west, owing to Earth's west-to-east rotation on its axis. Yet it rises exactly east and sets exactly west only at the spring and fall equinoxes.

After September's fall equinox, the Sun rises slightly further south of east each day until the winter solstice when it reaches its maximum rising distance south of due east. At this southern-most point, it stops moving southward and rises at virtually the same point on the horizon for several days. In that this rising point stands still, it is called a solar standstill, or solstice.

At the winter solstice the Sun, with its path tilted south (in our hemisphere), is in the sky the shortest length of time, making it the shortest day of the year.

After winter solstice the Sun's rising point along the horizon then reverses direction and begins moving northward each day, reaching due east on March's spring equinox. It then continues moving northward until June's summer solstice when it reach its maximum distance north of east. (The setting Sun does the same thing in the west.)

For any location, the standstill point on the horizon depends upon its latitude. For much of Texas that point is about 27 degrees south of east for the winter solstice. The width of your fist held at arm's length is about 10 degrees, so that's nearly three fists. And the summer solstice is the same distance north of east, making for the year's longest day.

So now you can awe your friends by telling them that the Sun will stand still on December 21.

  • Next Two Weeks: Average sunrise: 7:25 a.m.; average sunset: 5:30 p.m. (for Waco, TX)
    * Monday (Dec. 18) morning a thin crescent Moon is to the right of Jupiter which is above Mars low in the east southeast at dawn.
    * Tuesday (Dec. 19) is Saturnalia, the ancient Roman festival honoring the Roman god Saturn, father of Jupiter.
    * The Moon is new Wednesday (Dec. 20).
    * Thursday (Dec. 21) evening a thin crescent Moon is to the left of Venus low in the southwest at dusk.
    * The night of Dec. 22 the Ursid meteor shower, with meteors radiating from near the North Star, peaks with no Moon interference.
    * The Moon is at 1st quarter Dec. 27.

  • Naked-eye Planets: Venus is emerging as the "evening star" low in the southwest at dusk. Saturn, rising in the late evening, is high in the south by morning. Jupiter and Mars are low in the east southeast before dawn.

  • Astro Milestones: Dec. 25 is the 364th birthday of Isaac Newton (1642-1727), father of modern physics, and Dec. 27 is the 435th birthday of Johannes Kepler (1571-1630), whose discovery that planetary orbits are elliptical confirmed the Copernican sun-centered theory of the solar system.

  • Stargazer Book: My book, A Beginner's Guide to Learning the Night Sky, would make a great gift for that stargazer in your life. Check with your local bookstore or my Web site.

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December 2, 2006

Names of Some Prominent Stars of Fall and Winter

Of the several thousand stars visible to naked eyes, only a few hundred have names--names that came mostly from legends, myths and religions of common folks like hunters, herdsmen and sailors. While these names have little import to astronomers, who give stars numbers, they are embraced by stargazers and folklorists.

Many star names relate to the constellation of which the star is a part. In some cases, single stars represent and bear the name of an entire entity, usually an animal, person or god.

Some star names date back to the ancient Greeks and Babylonians, but many come from the Arabs of the Middle Ages. Some are Arabian translations of names ascribed by the ancients. According to an early Arab: "Thou canst not know how much we Arabs depend upon the stars. We borrow their names in gratitude, and give them in love." Muhammad reportedly said, "God hath given you the stars to be your guides in the dark both by land and sea."

Here are the names of some of my favorite fall and winter stars.

The two brightest stars of Gemini, the Twins, are Castor and Pollux, sons of the mythical queen Leda. Curiously, although Castor was mortal, his father being Leda's human husband, his twin Pollux was the immortal son of the god Zeus.

In Orion, the Hunter, Betelgeuse, marking his right shoulder, literally means armpit. Rigel means left leg. Bellatrix, marking his left shoulder, strangely means female warrior. Of the three stars that align to form Orion's belt, only Mintaka at the right end means belt. The middle star, Alnilam, means a string of pearls, and the left star, Alnitak, means girdle.

One of the most interesting stars is Algol, the demon star, in Perseus, the Hero. Algol is a variable star that dims noticeably for a few hours every 3 days, earning it a bad reputation. In Arabic Algol means the ghoul or mischief-maker. To the Greeks Algol is the head of Medusa who is so petrifyingly ugly that one look at her turns one into stone. To the Hebrews the star was satan's head, and the Chinese called it the piled-up corpses.

The bright red star, Aldebaran, is the red eye of Taurus, the Bull, but its name means the follower as it follows the lovely nearby Pleiades star cluster across the sky.

Sirius is the Dog-star in Canis Major, the Big Dog, and Achernar is the end of river in Eridanus, the River.

And finally, the northern hemisphere's best-known and, to the Greeks, "the most practically useful star in the heavens," is Polaris, the "pole star," also called the North Star.

  • Next Two Weeks: Average sunrise: 7:16 a.m.; average sunset: 5:25 p.m. (exact for Waco, TX)
    * Monday's full Moon is called the Long Night Moon and the Moon Before Yule.
    * Before dawn on Dec. 10 the Moon is less than two moonwidths from Saturn, and Mercury is just above Jupiter with Mars to their right, all near the east southeastern horizon.
    * By the next morning Jupiter and Mars are closer with Mercury just below them.
    * The Moon is at 3rd quarter Dec. 12.
    * The Geminid meteor shower peaks the evening of Dec. 13 with the best viewing from dark until the Moon rises at 2 a.m.

  • Star Party: The Central Texas Astronomical Society hosts a free star party at the Waco Wetlands Dec. 9 beginning at 7 p.m. For directions, see www.wacowater.com/wetlands.html.

  • Stargazer Book: My book, A Beginner's Guide to Learning the Night Sky, would make a great gift for that stargazer in your life. See PAUL'S BOOKS in this Web site for for a list of bookstores carrying the book, or for ordering directly from me.

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November 18, 2006

From Astrology to Astronomy

Just as chemistry evolved from the quasi-magical practice of alchemy, astronomy grew out of prescientific astrology. And for a time the distinction between astronomy and astrology was blurred.

In the early 1600s, when modern science was in its infancy, our world view was turned upside-down by the Copernicus revolution which removed Earth from the center of the cosmos. The two best known revolutionaries were Nicolas Copernicus who proposed the new view, and Galileo Galilei who used the newly-invented telescope to obtain supporting observational evidence.

But no less important was the contribution of Johannes Kepler whose discovery of elliptical orbits was the key that made the Copernican system work. So Kepler was a major player in one of history's most profound scientific revolutions.

Yet the astronomer-mathematician Kepler supplemented his income as an astrologer casting horoscopes. It's not clear whether he really believed in astrology or just cashed in on his knowledge of the heavens. Had he applied his meticulous and analytical mind to a critical study of astrology, he surely would have discovered some fundamental problems with the ancient system.

Traditional astrology identifies 12 constellations (the zodiac) through which the Sun passes, as it did long ago when astrology was born. It is the constellation the Sun was "in" at one's birth that determines one's astrological sign.

For example, someone born when the Sun was in Taurus presumably received certain traits which would be different had he or she been born a Gemini or Pisces.

But Earth's long-term wobble (called precession) has changed things. The Sun now passes through 13 constellations, the new one being Ophiuchus, and the dates

Although the traditional dates are used in horoscopes, here are the actual dates for each sign: Oct.30-Nov.22: Libra; Nov.23-Nov.28: Scorpius; Nov.29-Dec.17: Ophiuchus; Dec.18-Jan.18: Sagittarius; Jan.19-Feb.15: Capricornus; Feb.16-Mar.10: Aquarius; Mar.11-Apr.17: Pisces; Apr.18-May 13: Aries; May 14-Jun.20: Taurus; Jun.21-Jul.19: Gemini; Jul.20-Aug. 9: Cancer; Aug.10-Sep.15: Leo; Sep.16-Oct.29: Virgo.

So, if you believe in astrology, you've got to reconsider your sign. I was born Aug. 27, thus horoscopes tell me I'm a Virgo when really I'm a Leo. Although I'm not into astrology, I'd certainly rather think of myself as a lion than a virgin. So what's your sign?

  • Next Two Weeks: Average sunrise: 7:05 a.m.; average sunset: 5:26 p.m. (for Waco, TX)
    * Tonight the Leonid meteor shower is expected to peak -- before and after midnight.
    * Tomorrow morning (Nov. 19) just before dawn the crescent Moon is to the lower right of Mercury low in the east, and watch for any remaining Leonid meteors.
    * The Moon is new Monday (Nov. 20).
    * The Moon is at 1st quarter Nov. 28.

  • 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.) No naked-eye planets are now out in the evening. Mercury is near the eastern horizon at dawn with Saturn high in the south.

  • Astro Milestones: Nov. 20 is the 117th birthday of Edwin Hubble (1889-1953), American astronomer for whom the Hubble Space Telescope is named.

  • Stargazer Book: My book, A Beginner's Guide to Learning the Night Sky, would make a great gift for that stargazer in your life. See PAUL'S BOOKS in this Web site for ordering directly from me.

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November 4, 2006

Transit of Mercury

Our solar system consists of the Sun, planets and smaller objects which orbit the sun. Each planet orbits at a different speed, those nearest the Sun orbiting fastest. Earth makes one orbit each year (which is how we define a year) while the inner planets, Mercury and Venus, orbit in less than an Earth-year and the outer planets in more than a year.

When another planet passes on the opposite side of the Sun from Earth that's called a superior conjunction. The orbits of the planets are nearly, but not exactly, on the same plane, so when they pass behind the Sun at conjunction, they usually appear slightly above or below rather than exactly aligned with the Sun. But since conjunctions are only visible during the daytime they usually go unnoticed by most of us.

However in the case of Mercury and Venus, which orbit nearer the Sun than Earth, they periodically align between the Sun and Earth, called inferior conjunction. Usually they, too, pass just above or below the Sun, but sometime they align exactly in what's called a transit.

And that's about to happen with the upcoming transit of Mercury. The afternoon of Nov. 8, beginning at 1:12 p.m., the planet spends five hours passing across the Sun, appearing as a tiny black dot slowly moving across the Sun's face. The dot will be too small for naked-eye viewing so at least large binoculars or a small telescope will be needed.

If you have an opportunity to see the event, it's worth a look, but when viewing the Sun, safety is of utmost importance. Without a proper filter, the Sun can, in an instant, permanently damage one's eyes. A solar filter or welder's glass #14, used correctly, provides protection. The filter or glass should be placed between the instrument and the Sun (that is, in front of the instrument), not between it and your eyes.

Transits of Mercury are relatively rare, happening only 13 or 14 times each century. The next one occurs May 9, 2016, so try to catch this one if you can. (Check my website where I'll post any public observing opportunities I'm aware of.)

Transits of Venus, by the way, are more spectacular but much rarer. Since Venus is larger and closer to us, it is bigger and easier to see against the Sun. But Venus transits only 13 or 14 times each 1,000 years, the next one coming June 5, 2012.

  • Next Two Weeks: Average sunrise: 6:53 a.m.; average sunset: 5:32 p.m. (for Waco, TX)
    * Tomorrow night's full Moon is called the Frosty Moon and Beaver Moon, and also the Hunter's Moon, being the full Moon following the Harvest Moon.
    * The morning of Nov. 13, the 3rd quarter Moon is below Saturn.
    * The mornings of Nov. 17-19, the Leonid meteor shower, often one of the year's best, peaks with virtually no Moon interference this year; the best viewing is expected from midnight, when Leo rises, until dawn.
    * Nov. 17 the crescent Moon is above Virgo's Spica low in the east before dawn.

  • 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.) Early November sees only Saturn which rises after midnight and is high in the east in the morning. The other planets are too near the Sun for easy viewing.

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October 21, 2006

Buying a Telescope

It's not even Halloween, but if you're thinking of buying a Christmas telescope, it's not too early to start your planning. With telescopes it's best not to wait until the last minute or buy on impulse. While the right scope can provide a lifetime of enjoyment, the wrong one can be more frustrating than satisfying.

In this short column I don't have space for an effective Telescopes 101, but here are some pointers that should help.

There are several well-known, reputable telescope manufacturers, like Celestron, Meade, and Orion, each of which has a website and catalog. I especially like Orion's catalog that not only displays their products and prices, but has many educational sidebars which essentially provide a mini-course on types of telescopes and how they work. You can request a free catalog by calling 1-800-676-1343 or from their website at www.oriontelescopes.com.

If you're willing to drive to Austin, TX, a store named Austin Astronomy and Science is worth a visit. The folks who operate it are themselves knowledgeable stargazers, and they're not into high-pressure sales tactics. You can get more information about them at www.austinastronomy.com or 512-250-1252.

The Sky & Telescope website (www.skyandtelescope.com) has several articles which can be printed for free. See their menu bar on the left, then under Equipment, click on Choosing Your Equipment. It can also be helpful to visit with experienced stargazers, and in this area they're in the Central Texas Astronomical Society. CTAS is even conducting a free "Buying a Telescope" session in conjunction with its regular Nov. 11 public star party at the Waco Wetlands. Watch the events calendar on their website at centexastronomy.org for details.

I'm often asked about buying telescopes in department stores. I don't necessarily advise against it, but I suggest doing so only after some research--and don't expect the clerks to know any more about the telescopes they're selling than you do.

If you're new to stargazing, you'll also want to consider two additional and inexpensive items to help you learn your way around the night sky: a planisphere (starwheel) and my book, A Beginner's Guide to Learning the Night Sky. The book is available at Hastings in Waco, and a few other bookstores around Texas, or consult PAUL'S BOOKS in this website for ordering directly from me.

  • Next Two Weeks: Average sunrise: 7:41 a.m.; average sunset: 6:43 p.m. (for Waco, TX)
    * The Moon is new tomorrow (Sunday).
    * Monday (Oct. 23) evening a very thin crescent Moon is below Mercury which is below Jupiter, all near the southwestern horizon at dusk.
    * Then the next evening (Oct. 24) the Moon is to the planets' left.
    * Wednesday (Oct. 25) evening the Moon is to the left of Scorpius' brightest star Antares.
    * The Moon is at 1st quarter Oct. 29.

  • 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.) Mercury and Jupiter, low in the southwest at dusk, set soon after the Sun. Saturn rises after midnight and is high in the east in the morning. Venus and Mars are now behind the Sun.

  • Time Change: Sunday, Oct. 29 at 2 a.m. we return to Standard Time, so before retiring Saturday evening, set your clocks back 1 hour ("fall back") and get back that hour you lost last April.

  • Astro Milestones: Oct. 29 is the 350th birthday of Edmund Halley (1656-1742), English astronomer of Halley's Comet fame.

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October 7, 2006

SOFIA To Leave Waco

Since 1999, Waco has been the temporary home for SOFIA, NASA's Stratospheric Observatory for Infrared Astronomy. Under a contract with NASA, L-3 Corporation has been converting a 1977-model 747-SP (the "Clipper Lindbergh") into a flying observatory.

Originally scheduled for completion in 2002, budgetary and other hold-ups slowed progress, but completion is near. Early next year SOFIA will move to its permanent California home at Moffett Field. After 2 more years of testing, it will, in 2009, finally begin an anticipated 20-years of astronomical research, filling a void existing since the smaller Kuiper Airborne Observatory was retired in 1995.

The conversion included cutting a large hole in the side for a 2.5 meter reflector telescope--larger than the first McDonald Observatory telescope--in the rear section. The hole has a sliding door which, when SOFIA reaches observing altitutes, will open so the telescope has an unobstructed view of the cosmos.

Since we have the Hubble Space Telescope orbiting Earth and many observatories on Earth, why, one might ask, do we need one that flies in an airplane? Answer: Neither HST nor the ground-based scopes can do infrared research as well as SOFIA will do.

Ground-based instruments observe through Earth's atmosphere which even on cloudless days contains water vapor as well as air--both of which distort and block part of what astronomers wish to study. Space telescopes avoid atmosphere problems but are more expensive and far less accessible for modernizations and repairs. SOFIA is a good cost-effective compromise that flies beyond 40,000 feet to avoid over 99% of the water vapor, yet is easily accessible between flights.

SOFIA, as her name indicates, will focus on infrared radiation (heat rays), the part of the electromagnetic spectrum most blocked out by water vapor. The cosmos is full of activity across the entire range of this spectrum from radio and infrared at one end to ultraviolet, x-rays and gamma-rays at the other. Visible light which our eyes see is but a tiny slice in the middle of this spectrum, so our eyes miss much of what's going on.

Until modern times we were "blind" to these other parts of the spectrum, unaware they even existed as we lacked means for detecting them. Infrared radiation is also invisible to optical telescopes (like the HST) and human eyes, but SOFIA, with its infrared sensors, will enable astronomers to "see" this range as well. By studying the heat radiated by distant objects, we can learn more about galaxy, star and planet formation, black holes, and maybe even signs of other life.

Learn more about SOFIA at http://www.sofia.usra.edu/.

  • Next Two Weeks: Average sunrise: 7:31 a.m.; average sunset: 6:58 p.m. (for Waco, TX)
    * Friday the Moon is at 3rd quarter, and Friday the 13th is an unlucky day for the superstitious.
    * The morning of Oct. 16 the crescent Moon is just to the upper left of Saturn in the east, and that evening Mercury is at its best, but still low above the western horizon at dusk, below much brighter Jupiter.
    * The next morning the Moon is below Leo's brightest star Regulus with Saturn further up.

  • Astronomy Class: The Stargazer's four-session "Learning the Night Sky" class is Oct. 9-12 from 7-9 p.m. The cost is $25 per person with family discounts and free scholarships available. Call or email for information or to register.

  • Star Party: The Central Texas Astronomical Society hosts a free public star party at the Waco Wetlands Oct. 14 beginning at 7 p.m. For directions, see www.wacowater.com/wetlands.html.

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September 23, 2006

Constellations from the Ancients

To the ancients the night sky held more importance than it does for us today. Early humans were nomads who hunted and gathered from place to place. With no compass to guide them, the stars could help them find their way.

Later humans became farmers whose survival depended upon the success of their crops. Having no calendars, stars could tell them when to prepare for cold weather or the rainy season or when to plant.

To help them learn their way around the night sky, they invented picture patterns among the stars which we now call constellations. These imaginary sky pictures varied among cultures. Where one culture saw a bear, another might see a tiger or weapon or a god--it didn't really matter what image was visualized. Nor did the pattern have to closely resemble the object imagined (and most don't). The point was that sky pictures provided a useful method for recognizing individual and groupings of stars by associating them with surrounding stars.

Perhaps a culture of ancient agrarians noted that during the long cold season (which we call winter), the appearance of an especially bright star high in the south at sunset meant the cold season was nearly over, and it was time to prepare the ground for planting. Since there are a number of bright stars, it was important to know which one was the "ground preparing" star.

Noticing the other stars around it, maybe the pattern reminded someone of a big dog. So they learned that when the Big Dog with its bright Ground Preparing star (which we now call Canis Major and Sirius) became prominent in the south in the early evening, the warmer growing season was not far off.

Sky pictures also served religious and emotional purposes. One can imagine the comfort our ancestors derived from believing that sky gods were keeping a watchful eye on them and the world below. Of course, their belief in sky gods was also used by priests and other leaders to control their behaviors and to justify wars, slavery, conquests, human sacrifices and other atrocities.

We in the western world still use many of the sky pictures handed down by the Greeks, Babylonians (modern-day Iraq) and more ancient civilizations. These constellations continue to help us moderns learn the night sky just as they helped our ancestors. The Stargazer's classes (see below) can help you learn some of the constellations invented by our ancestors many centuries ago.

  • Next Two Weeks: Average sunrise: 7:22 a.m.; average sunset: 7:15 p.m. (for Waco, TX)
    * Tomorrow evening the crescent Moon is to the left of the star Spica low in the west, and Tues. evening to the left of Jupiter low in the west southwest.
    * Wed. evening Mercury is two moonwidths above slightly fainter Spica near the western horizon at dusk, and the Moon is below the star Antares in the southwest.
    * The Moon is at 1st quarter Sept. 30.
    * The Oct. 6 full Moon, coming nearest the fall equinox, is this year's Harvest Moon, and as it happens to occur near perigee, when the Moon is nearer Earth, this Harvest Moon will appear slightly larger than average.

  • Astronomy Class: The Stargazer's four-session "Learning the Night Sky" class will be held Oct. 9-12 from 7-9 p.m. The cost is $25 per person with family discounts and free scholarships available. Call or email for information or to register.

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September 9, 2006

Sadness At an Old Friend Slighted

OK, we've always known Pluto was different. He doesn't look like the others, he's way out of the mainstream, he travels his own odd path, and he's not on the level. He never did really fit in, but still I liked him. So why did they kick that poor dog out of the Disney family. Oh, it was the other Pluto? Never mind.

Sorry, I just couldn't resist. Apologies to the late, great SNL star Gilda Radner, but I have to keep some sense of humor about this topic. Now to get serious: Aug. 24, 2006, in Prague, Czech Republic, some 2,500 astronomers at the 26th General Assembly of the International Astronomical Union voted that Pluto isn't the 9th planet after all--it's merely a dwarf planet.

Their reasoning was logical and sound, and the decision will probably prove to be the right one in the long run. The rationalist in me simply can't argue with their action.

So why am I still sad and upset. Am I finally getting so old I can't adjust to progress? Geez, I'm a liberal Democrat who has been advocating progress all my adult life--civil rights, women's rights, economic justice, gay rights, universal health care--you name it. So I think I can handle change.

Apparently it's not just me. There seem to be others--and not just stargazers--distressed by the IAU decision. In an effort to better understand our feelings, my stargazer self turned to my Ph.D. behavioral scientist self (now retired) to suggest an explanation, and this is the theory he came up with.

When we look deep within ourselves, we all know our growing-up experiences left us with at least a few insecurities. Perhaps, for some of us, Pluto subconsciously represents some of those insecurities.

For a moment put yourself in Pluto's place: Ever since you were discovered in 1930 you've known you were different, but you hoped it wouldn't be noticed. You've looked enviously at popular Earth covered with friends, beautiful Saturn with its rings, bright Venus, big Jupiter and all the rest. You've known some even questioned your planethood. And now the most dreaded of all those deep-seated fears--the fear of rejection--has come to pass. Poor little underdog you, the runt, has been kicked out of the family.

All pretty universal human insecurities--so it wouldn't be surprising if some of us have come to love and identify with little Pluto because it's not big, bright and popular. If so, then maybe our next step in getting over it is to realize that no one has rejected us. Only Pluto--one of but millions of remote, icy chunks of solar system debris--was demoted.

Even so, I think I'll always feel a little sadness for the humiliation suffered by my old friend.

  • Next Two Weeks: Average sunrise: 7:13 a.m.; average sunset: 7:33 p.m. (for Waco, TX)
    * For the third time this year Jupiter passes near Libra's brightest star, double-star Zubenelgenubi, coming closest at one moonwidth Tuesday evening, Sept. 12. (Binoculars will help see the double's fainter companion.)
    * The Moon is at 3rd quarter Thursday.
    * The crescent Moon is below the Beehive star cluster low in the east the morning of Sept. 18, then below Saturn the next morning.
    * The Sept. 22 new Moon features an annular eclipse of the Sun which won't be visible from the U.S.
    * Sept. 22 is also the fall (autumnal) equinox when night and day are of equal length.

  • Public Star Party: The Central Texas Astronomical Society hosts it free monthly star party Saturday evening, Sept. 16, at the Waco Wetlands starting at 8 p.m. For directions, see www.wacowater.com/wetlands.html.

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August 26, 2006

What's All the Buzz about Planets?

Scientists frequently hold important meetings, most of which elicit widespread public ho-hum. Indeed, most of their technical discussions would quickly put us lay folks to sleep.

Not so with the recent convening of 2,500 astronomers in Prague, Czech Republic. The 19th General Assembly of the International Astronomical Union has generated surprising public interest and media attention--at least one aspect of the 2-week assembly. While most of their sessions would still put many of us asleep, not so with the issue of defining a planet.

Astronomy, regarded by many as the oldest field of science, has been around for centuries, yet surprisingly there has been no official definition of a planet. For most of astronomy's history, this wasn't a problem as the then-known planets were so different from anything else in the heavens. But Clyde Tombaugh's 1930 discovery clouded the issue just a bit. He found a faint object beyond Neptune that came to be regarded as the 9th planet named Pluto. For decades it was thought to be larger than Mercury so there were few serious objections to considering it a planet.

But in 1951 Gerard Kuiper created more clouds when he theorized the existence of a disk of icy-type objects orbiting the Sun beyond the orbit of Neptune.

His idea wasn't too off-the-wall as a similar disk of rocky-type objects, now known as the asteroid belt, had been discovered in the early 1800s between the orbits of Mars and Jupiter. The largest asteroid, Ceres, being less than 600 miles in diameter, wasn't considered a serious contender as a planet.

But the issue got much cloudier with the discovery that Pluto was smaller than Mercury, and even smaller than our Moon and several moons of other planets. Should an object that small be considered a planet? Then in 1978 James Christy found Pluto has a moon half its size, now named Charon.

Within the past few years discovery of a number of distant objects has verified the existence of what is now called the Kuiper Belt, and many began to regard Pluto as just an unusually large Kuiper Belt object that should not be called a planet.

Then Michael Brown's discovery last summer of a Kuiper Belt object slightly larger than Pluto (tentatively dubbed Xena) was the final cloud. The IAU simply had to come up with a clear definition. A somewhat radical proposal was to be debated and voted on Aug. 24 (after this column was written). So more next time on what comes out of the historic 19th IAU General Assembly.

Breaking News: Pluto demoted. More next time.
  • Next Two Weeks: Average sunrise: 7:05 a.m.; average sunset: 7:51 p.m. (for Waco, TX)
    * Tomorrow morning Venus is within a moonwidth of Saturn near the northeastern horizon at dawn.
    * Tues. evening the crescent Moon is to Jupiter's lower left low in the southwest soon after dark.
    * Thurs. evening the 1st quarter Moon is just below Antares.
    * The first two weeks of Sept. Jupiter is near the double star Zubenelgenubi, coming closest at one moonwidth on Sept. 12. Binoculars will help see the fainter companion star.
    * The Sept. 7 full Moon, called the Fruit Moon, features a partial lunar eclipse which won't be visible from the U.S.here.

  • Star Party: Today's Lake Whitney State Park Star Party begins with indoor programs at 4 p.m. and outdoor guided sky tour and telescope viewing starting at dark. The event is free except for the nominal park entry fee.

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August 12, 2006

Perseid Meteor Shower

Tonight the annual Perseid meteor shower peaks, but don't get too excited. Usually one of the best showers, this year the Moon will wash out all but the brightest Perseids.

A large gibbous Moon rises around 10:30 p.m., and with skies not getting dark until 9 p.m. or so, that doesn't leave much time for moonless meteor watching. And unfortunately, meteor showers are usually at their best after midnight, by which time the Moon will be well up in the night sky.

However don't give up completely. It doesn't mean no meteors will be seen--just fewer since only the brightest ones will be visible against the moonlit night sky.

With the Moon up, it won't be necessary for city folks to travel to rural areas for a better show. The Moon is the great equalizer that lights up everyone's sky. Rural areas, with less light pollution, usually reveal far more night sky objects, but when a bright Moon is out, it washes out the sky just like city lights.

But the Moon hasn't always been unwelcomed. Some 200 years ago when modern science was in its infancy, a group of English scholars held monthly scientific discussions, calling their group the Lunar Society. Sounding like a group of astronomers with special interest in the Moon, the Society actually included a much wider range of luminaries like Erasmus Darwin (Charles' grandfather), James Watt (whose name is a measure electricity, e.g., a 60-watt bulb), Joseph Priestley (discoverer of oxygen) and even Benjamin Franklin during periodic visits to England.

While their interests spanned the spectrum of the sciences, their name derived from a practical consideration. Since there were no street lights then, they met each month on a night near the full Moon so they could see their way home.

The Moon is most brilliant two days before to two day after full Moon; just three days before or after, the sky is less than half as bright as at full. Fortunately the Perseids peak three days after the Aug. 9 full Moon, so as darkness falls tonight, stretch out on a blanket or reclining lawnchair, face west (as the Moon rises in the east) and start watching for those beautiful "falling stars." Or better yet, come out to Reynolds Creek Park amphitheater -- see below.

  • Next Two Weeks: Average sunrise: 6:56 a.m.; average sunset: 8:08 p.m. (for Waco, TX)
    * The Moon is at 3rd quarter Tues., and near the Pleiades the next morning.
    * Fri. morning, brilliant Venus is two moonwidths to the right of the Beehive star cluster low in the east just before dawn. (Binoculars will help.)
    * The morning of Aug. 21 at dawn, Venus is in the middle of a great alignment with the Beehive and thin crescent Moon above it; below Venus are Saturn and two moonwidths further down brighter Mercury just above the horizon.
    * The next morning an even thinner crescent Moon is to the left of the three planets.
    * The Moon is new Aug. 23.
    * A thin crescent Moon is to the left of Mars the evening of Aug. 25 near the western horizon at dusk.
    * Jupiter is the brightest object in the southwest in the evening throughout the fortnight.

  • Star Party Tonight: Beginning at 8:30 tonight at Reynolds Creek Park amphitheater (formerly Speegleville I Park), the Central Texas Astronomical Society will host a free slide program ("Constellations of the Season") followed by a laser-pointer sky tour, telescope viewing and meteor watching. For directions see http://www.swf-wc.usace.army.mil/waco/Speegi.htm.

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July 29, 2006

Space Exploration

Surely all who were paying attention breathed a sigh of relief recently when Discovery safely returned to Earth from its mission to the International Space Station. Several tragic catastrophes have been painful reminders of the risks of venturing into space.

Given our enormous and growing federal deficit and the almost overwhelming problems we face here on Earth, some question whether we should expend resources exploring space. As a retired social worker and college professor I'm keenly aware of the human needs and sufferings that surround us daily that desperately need our resources.

Exploring space is expensive, yet even with our other pressing needs, can we really afford not to do it? I suspect ultimately the survival of our species will depend upon our conquest of space--developing new resources and even alternative "homes."

Before retiring a few years ago, I recall that for most of my 35-year career, retirement seemed an eternity away. There were times my family could have used the money withheld for Social Security and other retirement accounts. But now we're surviving on what we invested in our future many years ago.

Space exploration, I think, is our investment in humanity's future--not necessarily our own, or even that of our children or grandchildren, but that of future generations. I'm grateful our ancestors invested in the future by exploring and opening up new worlds, even when they themselves didn't reap the benefits.

As badly as we're treating Mother Earth in so many ways, space exploration seems the least we can do for posterity. We don't necessarily need the 1960s-type of space-race urgency, but what we do need, rather than inadequately funded rhetoric about "sending a man to Mars," is steady and meaningful support in our federal budget.

Can we address our immediate issues and simultaneously invest in humanity's future in space? Even with my frequent discouragements about the short-sighted leadership in our country and throughout the world, I'm still a long-term optimist.

We seem to be a remarkably resilient species. Looking at our history and realizing what we have survived thus far gives me hope for our future--not a blind, pie-in-the-sky hope of certitude, but a reasoned hope in the probability that we will muster the will and the wisdom to do what we must to survive.

  • Next Two Weeks: Average sunrise: 6:47 a.m.; average sunset: 8:21 p.m. (for Waco, TX)
    * Tues. (Aug 1) is Lammas, marking the middle of summer.
    * Tues. evening the Moon is below Jupiter.
    * The Moon is at 1st quarter Wed. (Aug 2).
    * Thurs. evening (Aug. 3) the Moon is to the right of Scorpius' bright star, Antares, and the next evening to its left.
    * The Aug. 9 full Moon is called the Green Corn Moon, Grain Moon and Fruit Moon.

  • Naked-eye Planets: Evening: Mars is low in the west at dusk while bright Jupiter is higher in the southwest. Morning: For the next three weeks Mercury is below much brighter Venus low in the east just before dawn, and coming closest Aug. 10.

  • No Mars Spectacular: It's circulating on the Internet again, but don't believe it--Mars is not about to come spectacularly close to Earth nor will it look as large as the full Moon. Each summer since Mars' close encounter in August 2003 this email has come around. It's a great reminder that we can't believe everything we read on the Internet.

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July 15, 2006

The Lure of the Stars

My personal journey to the stars began in 1954 when an 81-year old stargazer, Margaret Willits, fascinated me with her love for and familiarity with the night sky. She gave me some items she had collected over the years, one being "Lure of the Stars," a booklet by an editor of Scientific American.

Upon re-reading this 1910s booklet, I was again struck by how much we've learned in the past 100 years, and how wrong we were about some things a mere century ago.

The booklet speaks of the solar system with its eight planets. The discovery of Pluto not coming until 1930, some astronomers in the 1910s were quite sure there were no planets beyond Neptune.

The nature of comets was still largely unknown, being described as "ghosts of the skies that do not disturb the planets...when they pass by." While it's true they usually don't, we now know they certainly can be disturbing. When two dozen pieces of Comet Shoemaker-Levy 9 crashed into Jupiter in 1994, they left huge explosive smudges visible for months. Had they crashed into Earth--and it's happened before--it would have been devastating.

It states that comets "are self-luminous with their brightness probably increased by reflected sun-light." This isn't completely wrong, but we now know nearly all of a comet's glow is reflected sunlight. The faint bluish ion glow they emit is generally seen only in astrophotography.

The booklet has pictures of the "Great Nebula of Andromeda" and the "Pinwheel of Space, a Spiral Nebula," described as "great Star Factories, making up star balls and throwing them off billions of miles into space." It was thought our Milky Way was the entire universe. We now know these "nebulae" are other galaxies--the Andromeda and Pinwheel Galaxies--like our Milky Way galaxy, and there are many billions of them. The cosmos is vastly larger than astronomers imagined 100 years ago.

As outdated as the booklet is in some ways, two of its lessons will never be obsolete. No matter how smart we are today, there have been equally brilliant people around for thousands of years, making astounding discoveries using little more than their minds. And in view of all we know today--and we know a lot--we must not forget that some will eventually be proven wrong. But that's how science works. Gradually, tediously, sometimes even taking backwards steps, we build that body of scientific knowledge that has, in so many ways, immeasurably increased the quality of our life on planet Earth.

  • Next Two Weeks: Average sunrise: 6:38 a.m.; average sunset: 8:31 p.m. (for Waco, TX)
    * The Moon is at 3rd quarter Monday.
    * Thurs. morning the crescent Moon is just below the Pleiades star cluster in the east before dawn.
    * July 21 & 22 reddish Mars passes within two moonwidths of Leo's slightly brighter star Regulus low in the west at dusk.
    * July 22 & 23 the Moon is above, then to the lower left, of Venus low in the northeast at dawn.
    * The Moon is new July 24. July 26 & 27 the crescent Moon is to the lower right, then upper left, of Regulus and Mars low in the west at dusk.

  • 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.) Saturn is rapidly approaching the setting Sun low in the west at dusk while Mars hovers a bit to its upper left. Jupiter is the bright beacon in the southwest. Venus, the "morning star," dominates the eastern sky at dawn.

  • Public Star Party: The Central Texas Astronomical Society hosts a free star party tonight at the Waco Wetlands at 9 p.m. For directions, see www.wacowater.com/wetlands.html.

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July 1, 2006

The Wobble That Changes the Sky

When something develops a wobble it often means a problem. But in the case of Earth, its wobble is but one result of an event that has profoundly affected life on our planet.

Some 4-5 billion years ago, when our solar system was in its formative stages, a Mars-sized planet likely collided with Earth, destroying the smaller planet and drastically altering our planet. Blasted-away debris from that colossal collision eventually coalesced and formed our Moon.

And Earth, which presumably had been orbiting perpendicularly to its orbit, with its north and south poles straight up and down, was knocked a little wacky and left with a 23 1/2 degree tilt. (You've probably noticed the tilt on mounted Earth globes.)

It is because of this tilt that we have seasons. As Earth makes its annual orbit around the Sun, the northern and southern hemispheres take turns tilting toward the Sun. Now, with our Northern Hemisphere tilted toward the Sun, we are having hot, long summer days. But the Southern Hemisphere, being tilted away from the Sun, is having cold, long winter nights. The half-way points between these extremes are fall and spring with moderate temperatures and days and nights of equal length.

So, what about the wobble? Think of Earth as a spinning toy top. Not only does a top rapidly spin on its axis, but it also has a slower wobble that becomes more noticeable as the spin slows down. Earth, which rotates on its axis each day, also has a very gradual wobble that takes 25,800 years, and which astronomers call precession. Over a human lifetime, it is undetectable without precise measuring instruments. But over longer periods, precession becomes quite apparent when one views the night sky.

In our era, the star Polaris is almost straight up from Earth's north pole, making a nice, moderately bright North Star. In a few centuries, however, owing the wobble of precession, Polaris will no longer be above Earth's north pole and won't do for a North Star--at least not for another 25,000 or so years.

Precession also affects what constellations are seen each season. For us, Scorpius let's us know it's summer while Orion dominates our winter night sky. In 12,900 years--half way through a precession wobble--this will be reversed. Our Northern Hemisphere ancestors, if any are still around, will see Orion in the summer and Scorpius in the winter--just as Southern Hemisphere Earthlings do right now.

  • Next Two Weeks: Average sunrise: 6:30 a.m.; average sunset: 8:37 p.m. (for Waco, TX)
    * This morning Venus is to the upper left of the Hyades star cluster and bright Aldebaran.
    * Tomorrow is the midpoint of 2006.
    * Monday the Moon is at 1st quarter, and Earth reaches aphelion, the point in its elliptical orbit where it is farthest from the Sun.
    * The Moon is to the lower left of Spica Tuesday evening, below Jupiter Wednesday, and to the right of Antares Friday.
    * The July 10 full Moon is called the Thunder Moon, Hay Moon and Grain Moon.

  • 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.) Evening: Mercury, Saturn and Mars are aligned diagonally low in the west with Mercury just above the horizon at dusk, Saturn 10 degrees to its upper left, and Mars 8 degrees to Saturn's upper left. (The width of your fist held at arm's length is 10 degrees.) Jupiter is the brightest object midway up in the south. Morning: Venus, rising 2 hours before the Sun, is the "morning star" low in the northeast.

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June 17, 2006

Moon's March through the Planets

Over the next two weeks we'll have a great opportunity to watch the Moon march by 4 of the 5 naked-eye planets, including the elusive Mercury. The march begins in the morning and ends in the evening.

Thursday morning, an hour before sunrise, the crescent Moon is above Venus, the brilliant "morning star," with the lovely Pleiades star cluster to Venus's left low above the western horizon. The next morning finds an even thinner crescent Moon nearer the horizon, to the left of Venus and below the Pleiades.

The June 25 new Moon seems to disappear while passing between the Earth and Sun, and preparing to move into the evening sky.

The march resumes at dusk June 26 when an ever-so-thin crescent Moon is to the right of Mercury just above the western horizon. Binoculars might be needed.

The highlight of the show occurs the next evening when a slightly larger crescent Moon is above Mercury and to the right of Saturn and the Beehive star cluster with Mars to Saturn's upper left. Saturn is the brightest of the three planets.

But the show isn't quite over as the next evening (June 28), the Moon is just above Mars.

Viewing the Moon over several nights affords the opportunity to note some subtle changes that occur regularly in the night sky. After new Moon, the Moon grows slightly more illuminated each evening. On June 26 just the tiniest part is lighted, but each night thereafter the crescent grows fuller, thus it's called a waxing (increasing) crescent Moon.

The Moon also rises later each night, as much as 70 minutes some times of the year, and other times as little as 30 minutes. On average it comes up about 50 minutes later each night.

Finally, since the Moon orbits Earth every 27.3 days moving in an easterly direction, it appears 13 degrees east of where it was the same time the night before, relative to the background stars--a distance called a moonstride. By a handy coincidence, when making a "hook 'em horns" sign at arm's length, the distance between one's index and little fingers is a moonstride. Holding your left hand at arm's length and aligning your index finger with the Moon, note which stars (and planets if any) your little finger is pointing to--that's where the Moon will be the next night. (While this is easy for us Longhorns, I realize it's hard for Aggies and Bears, but it will be dark and no one will see.)

  • Next Two Weeks: Average sunrise: 6:25 a.m.; average sunset: 8:37 p.m. (for Waco, TX)
    * This evening Mars passes within one moonwidth of Saturn with both to the upper left of the Beehive cluster.
    * The Moon is at 3rd quarter tomorrow.
    * Tues. evening presents the best view of Mercury as it reaches greatest elongation--highest above the setting Sun--low in the west at dusk.
    * Wed. is the summer solstice in the Northern hemisphere--the first day of summer and year's longest day (and first day of winter and year's shortest day below the equator).
    * The evening of June 29 the Moon is to the right of Regulus.

  • Public Star Party: The Central Texas Astronomical Society will host a free star party at the Waco Wetlands tonight starting at 9 p.m. For directions, see www.wacowater.com/wetlands.html.

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June 3, 2006

Beehive Still Abuzz with Activity

The Beehive star cluster continues to buzz with activity. Together with Saturn and Mars, it is putting on an evening show not to be missed, and it's getting better each night.

While best seen under dark rural skies, the show can also be seen from urban areas with binoculars. Just after dusk Saturn is the brightest starlike object 30 degrees above the western horizon. (The width of your fist held at arm's length is 10 degrees.) Not as bright as creamy-colored Saturn, reddish Mars is a half-fist to the lower right. And to Mars' right are Gemini's two brightest stars, Pollux and Castor. All these objects are easily seen with naked eyes.

The Beehive star cluster is more of a challenge, especially now with the interfering glare of moonlight. To naked eyes the cluster looks like a moon-sized fuzzy glow to Saturn's upper right. Binoculars, however, reveal the Beehive's true nature--a dazzling swarm of faint stars. Skimming along the edge of the Beehive, Saturn remains less than 1 degree (two moonwidths) from the cluster's center through the first week of June as it gradually moves to the cluster's upper left.

But as Saturn slowly pulls away, Mars rapidly approaches. Being nearer the Sun than Saturn, Mars travels faster in its orbit--54,000 mph compared 22,000 mph. So Mars moves faster against the background stars, and is gaining on Saturn.

Both planets and the cluster are within the same field of view of most binoculars. Mars is approaching the cluster at the rate of just over 1/2 degree (one moonwidth) per night. The highlight of the show comes June 15 as Mars passes through the cluster with Saturn just 1 degree to their upper left. Then two nights later Mars passes within 1/2 degree of Saturn. Ah, what a show.

Watching this episode nightly will also provide an opportunity to observe two phenomena. The first is the nightly movement of a rapidly moving planet--Mars--as mentioned above.

The other is the gradual nightly east-to-west movement of the entire sky due to Earth's orbit around the Sun. Through the first two weeks of June, the Beehive and planets will move more than 10 degrees nearer the horizon as the sky darkens. Since the show sets by midnight, don't wait too late to view it.

  • Next Two Weeks: Average sunrise: 6:23 a.m.; average sunset: 8:33 p.m. (for Waco, TX)
    * The Moon at 1st quarter tonight.
    * Tues. evening a bright gibbous Moon travels across the sky to the right of Virgo's Spica until they set around 3 a.m.
    * The Moon is to Jupiter's right Wed. evening, then below the bright planet the next night.
    * Sat. evening the nearly full Moon is to the lower left of Scorpius' Antares.
    * The June 11 full Moon is called the Rose Moon, Flower Moon and Strawberry Moon.

  • 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.) Evening: In addition to Saturn and Mars discussed above, Jupiter is mid way up in the southeast while Mercury is emerging in the west northwest just above the horizon after sunset. Morning: Venus remains the lovely "morning star."

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May 20, 2006

Mother Nature's End-of-Month Specials

Mother Nature is offering some attractive end-of-month specials you won't want to miss. These early evening delights involve stars, planets and the Moon low in the west as darkness falls.

The evening of May 30, a thin crescent Moon will be 6 moonwidths to the right of Mars, and to the Moon's right will be Gemini's brightest stars, Pollux and Castor. The planet, Moon and stars will be about evenly spaced in a straight line with reddish Mars nearly the same brightness as the stars.

The next evening the Moon will be within 4 moonwidths above the Beehive star cluster with Saturn less than 2 moonwidths below the cluster. Saturn looks like a bright, creamy colored star.

Unless being viewed under dark, moonless skies, the Beehive is easy to miss. To naked eyes it appears as a faint, moon-sized fuzzball. In binoculars dozens of individual stars are visible, looking like the swarm of bees for which it is named.

From our perspective all these objects seem close together, but appearances are deceiving. The Moon, at a mere 240,000 miles away, is next door. Mars' distance from Earth varies depending upon where the two planets are in their orbits. It can be as near as 34 million miles and as far as 250 million miles; now it's 200 million miles away. Its differing distances account for its varying brightness. When nearest it outshines all the stars; now, nearly at its faintest, there are 30 brighter stars. Saturn at 900 million miles is nearly 5 more distant than Mars and a whopping 3,700 times further than the Moon.

But these solar system objects are virtually in our back yard compared to the Beehive star cluster. Expressed in miles, its distance is beyond reasonable comprehension: 3 quadrillion miles--a number larger even than our national debt.

That's why astronomers use light years for measuring distances beyond the solar system. A light year is the distance light travels in a year, which moving at 186,000 miles per second, is 5.9 trillion miles. That puts the Beehive at 515 light years away, a much more manageable number.

When viewing the Beehive cluster it's easy to forget that each of the "bees" is, in fact, a star like our Sun, although much younger ones. Our Sun is 5 billion years old while the stars of the Beehive cluster were formed recently, in cosmic terms--only 400 million years ago.

While you're out, don't overlook Jupiter, the brightest object high in the southeast.
  • Next Two Weeks: Average sunrise: 6:26 a.m.; average sunset: 8:26 p.m. (for Waco, TX)
    * Tonight the Moon is at 3rd quarter.
    * Wed. morning the crescent Moon is to the left of Venus low in the east.
    * The Moon is new May 27.

  • 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.) Evening: Mars, Saturn and Jupiter, as discussed above. By month's end Mercury begins appearing low in the west at dusk. Morning: Venus is still the "morning star" low in the east.

  • Public Star Party: The Central Texas Astronomical Society will host a free star party at the Waco Wetlands tonight at 9 p.m. For directions, see www.wacowater.com/wetlands.html.

  • Lake Whitney event: The Stars & Guitars Fest at Lake Whitney State Park on May 27 will feature live music during the day and an evening star party. See www.whitney-astro.com.

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May 6, 2006

Comet Schwassmann-Wachmann 3

We are well aware of the life cycle of biological beings which are born, live through stages, and eventually die. Indeed most, if not all, things in nature go through "life cycles"--they come into existence, follow generally predictable stages, and ultimately cease to exist. This includes stars, planets, galaxies, and perhaps even the universe itself.

We may now be witnessing the end stages of Comet 73P/Schwassmann-Wachmann 3. Discovered in 1930 by Arnold Schwassmann and Arno Arthur Wachmann, the comet is actually billions of years old.

Like planets, moons and asteroids, comets formed as by-products of star-birth. When our Sun was born 5 billion years ago, some of the star-making material was left over. Millions of comets--frozen chunks of "dirty ice" ranging from several feet to several miles in diameter--orbit our Sun far beyond Pluto where most will live out their lives. Some, however, through random collisions and other events, have their orbits altered so that they periodically swing down nearer the Sun into our part of the solar system.

When this happens the Sun's heat melts away part of the comet's outer layer, freeing some of the dust and gasses locked within the ice, and creating a fog-like cloud, called the coma, surrounding the comet's solid nucleus. Solar winds gently blow some of this cloud away from the nucleus, forming the tail which can extent for millions of miles. When we see a comet, we don't see its solid nucleus. All we see is sunlight reflecting off the coma and tail.

Many comets that enter the inner solar system make but one trip. Some fall into the Sun and are destroyed; others are hurled back into space. Some, however, develop orbits that bring them back on a regular, predictable basis. Although not as large and dramatic as the famous Halley's Comet which returns every 76 years, Comet Schwassmann-Wachmann 3 has been coming around every 5 years.

But it may not have many more trips before it dies. The comet has begun to break apart, somewhat like Comet Shoemaker-Levy 9 which broke into some two dozen pieces in the early 1990s before plunging into Jupiter. Schwassmann-Wachmann 3 isn't expected to crash into the Sun or any planets in the foreseeable future, but its nucleus could disintegrate into countless small pieces, essentially marking the end of its life.

Schwassmann-Wachmann 3 might reach naked-eye visibility, but the Moon is creating viewing problems. For specifics on seeing the comet, see my website at stargazerpaul.com or skyandtelescope.com.

  • Next Two Weeks: Average sunrise: 6:34 a.m.; average sunset: 8:17 p.m. (for Waco, TX)
    * Wed. night the Moon travels across the sky all night with Virgo's brightest star Spica, then spends the next night accompanying Jupiter across the night sky.
    * The May 13 full Moon is called the Planting Moon, Milk Moon and Flower Moon.
    * The morning of May 14 the Moon is near Scorpius' brightest star Antares low in the southwest at dawn.
    * In the early evenings of May, the Milky Way seems to vanish from the night sky as it lies flat around the horizon.

  • 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.) Evening: Mars, in the west in the early evening, sets around midnight. Higher in the west is Saturn which sets at 2 a.m. Jupiter is up all night--in the southeast in the evening and southwest by morning. Morning: Venus is still the beautiful "morning star" low in the east.

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April 22, 2006

Jupiter at Opposition

Jupiter, our solar system's largest planet, takes 12 Earth years to orbit the Sun, so while we make our annual solar orbit, Jupiter completes only 1/12 of its orbit. As a result we pass between Jupiter and the Sun about every 13 months. When this happens Jupiter is opposite the Sun as seen from Earth, a position called being at opposition. This next happens May 4. At opposition a planet rises in the east at sunset, is high in the south at midnight, and sets in the west at sunrise, thus it is in the sky all night. Now and for the next several weeks Jupiter will be at its best. Being as near to us as it gets, it's at its largest and brightest, and is up for evening viewing.

To naked eyes Jupiter looks like an unusually bright star, outshone only by Venus and the Moon. Now rising just before 9 p.m. it is the "evening star" dominating the eastern sky. A close look shows a neighbor two moonwidths to its right, a double star named Zubenelgenubi. Much fainter than the planet, it is the brightest star in the constellation Libra the Scales.

Viewed through most binoculars Jupiter still looks like a star. However 7-power or larger binoculars held very steadily--or better yet, rested on a fixed object--barely reveal Jupiter's round shape and even some of its moons. And not only do they now show Jupiter and Zubenelgenubi in the same field of view, they reveal the double star's faint companion star just above it.

Of course, Jupiter is at its best in a telescope. It is easily seen as a round object with at least two of its subtle belts usually visible. And even small scopes can show Jupiter's four largest moons, collectively called the Galilean Moons in honor of Galileo who discovered them in 1609. They look like four tiny stars aligned in a nearly straight line, although on any given night one or more might be hiding behind or in front of the planet.

So for the next several weeks Jupiter will be well situated for your viewing pleasure. Don't miss it.

  • Next Two Weeks: Average sunrise: 6:45 a.m.; average sunset: 8:07 p.m. (for Waco, TX)
    * Monday morning the crescent Moon is near Venus, and Thursday morning near Mercury.
    * The Moon is new Thursday.
    * Friday evening the crescent Moon is below the Pleiades near the western horizon at dusk, then the next evening above the cluster.
    * May 1 is May Day (aka Beltane), a cross-quarter day celebrating the middle of spring.
    * The evening of May 1 the crescent Moon is to the lower right of Mars, then the next night very close above it.
    * The evening of May 3 the Moon is between Gemini's brightest star, Pollux, and Saturn.
    * The Moon is at 1st quarter May 5.

  • Meteor Shower: This is a favorable year for the Eta Aquarid meteor shower which peaks the morning of May 6. Aquarius, from which the meteors appear to radiate, rises by 3 a.m. to a moonless sky, but this shower has a short viewing period as dawn begins to break less than three hours after Aquarius rises.

  • 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.) Evening: Mars is in the west until it sets around midnight. Saturn, higher in the southwest, is down by 3 a.m. Jupiter, low in the east in the evening, is in the southwest by morning. Morning: Mercury is visible near the eastern horizon at dawn, but quickly disappears into the morning Sun. Venus is still the brilliant "morning star" low in the east southeast.

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April 8, 2006

Using Venus to Find Uranus

In this column we usually discuss only naked-eye objects, but I'm finding that many people, especially those most likely to read Stargazer, do have binoculars. So to see the object of this column get out your binoculars, or borrow a pair from a friend.

The morning of Apr. 18 affords an excellent opportunity for even casual stargazers--those who enjoy the night sky but don't know their way around it very well--to see Uranus, a plant most have never seen. Your tour guide will be Venus, the beautiful and easy-to-find "morning star."

An hour before sunrise the two will be 12 degrees above the western horizon. (The width of your fist held at arm's length is 10 degrees.) You can't miss brilliant Venus which is far brighter than any star. Uranus, looking like a much fainter greenish star, will be to Venus' lower right, less than the width of a full Moon away. (For a nice contrast look for a reddish star as bright as Uranus but a little further to Venus' lower left.) If the glare of Venus interferes with seeing the fainter objects, aim your binoculars so Venus is just beyond your field of view.

Although smaller, Venus appears much brighter than Uranus as it is closer to us and to the Sun (the source of the light being reflected), and its cloud-enshrouded surface is very reflective. There are other ways in which the two are a study in contrasts.

Venus, the second planet out from the Sun (Earth being third), is a mere 68 million miles from the Sun while Uranus is 27 times more distant at nearly 2 billion miles. Venus has been known of since antiquity while Uranus wasn't discovered until 1781.

Astronauts have walked on the Moon and eventually will walk on other worlds. However neither Venus nor Uranus will ever know human footprints, but for very different reasons. With a surface temperature of 900 degrees, Venus is hotter than an oven, and its extreme air pressure would crush space craft. Uranus is quite cold, which is not a problem for astronauts, however, it is a giant gas planet with no surface for astronauts to walk upon. Just some things to think about while you're viewing them.

  • Next Two Weeks: Average sunrise: 7:00 a.m.; average sunset: 7:57 p.m. (for Waco, TX)
    * Thursday's full Moon, called Grass Moon, Egg Moon, Pink Moon and Milk Moon, is near the star Spica.
    * Friday (Apr. 14) night the Moon travels across the sky with Jupiter, in the east in the evening and southwest by morning.
    * The evenings of Apr 16-18, Mars passes near Gemini's tiny M35 star cluster. (Use binoculars.)
    * The morning of Apr. 17 the Moon is near the star Antares.
    * The Moon is at 3rd quarter Apr. 20.
    * The Lyrid meteor shower peaks the night of Apr. 21 with the best viewing from before midnight when Lyra rises until 4 a.m. when the Moon rises.

  • 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.) Evening: Mars, now in the west, sets after midnight. Saturn, high in the south, sets after 3 a.m., and Jupiter is up by 10 p.m. Morning: Venus rises 2 hours before the Sun, and Mercury an hour later.

  • Public Star Party: The Central Texas Astronomical Society will host a free star party at the Waco Wetlands April 15 at 8:30 p.m. For directions, see www.wacowater.com/wetlands.html.

  • Eclipse Countdown: It's now only 18 years until the Apr. 8, 2024, total eclipse of the Sun passes directly over the heart of Texas. Live healthily so you'll be around to see it.

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March 25, 2006

Solving Some Moon Mysteries

When the Moon is up it's usually the most dominant object in the night sky--bigger and brighter than anything else. It is no wonder that it's cited in countless songs and poems, and until the 1960s was the subject of much mystery and speculation.

Many questions about the Moon were answered by space probes and astronaut visits, yet it still holds many mysteries, like how and when did it form? does it now or has it ever had water? With more study these puzzles will be solved.

There are, however, other questions--mysteries in the minds of many--that we can answer now.

Q: When the Moon is half illuminated, why is it called a quarter Moon rather than a half Moon?

A: The Moon, like Earth, is always half illuminated with the side facing the Sun always lighted (day) and the side away from the Sun always dark (night). How much of the illuminated side we see depends upon where the Moon is in it monthly journey around Earth. When it's between Earth and Sun, called a new Moon, we can't see it at all because its unilluminated side is facing us. When it is half way around its monthly trip and on the opposite side of Earth from the Sun, we see the entire lighted side which we call a full Moon. It's when the Moon is one-fourth and three-fourths of the way around that we see it half illuminated, thus the terms 1st quarter and 3rd quarter refer to its position in it orbit rather than how it appears to us. (Of course, this being the case, we really should call the full Moon a half Moon since it's half way around in its orbit.)

Q: If the Moon turns on its axis, why does it look like the same side always faces us?

A: Indeed the Moon does turn on its axis, just like Earth, with one rotation making a Moon-day. But while Earth rotates once every 24 hours, the Moon rotates once every 29 1/2 Earth days, the same time it takes it to make one revolution around Earth, so the same side does always face us. Until 1959, when Russia's Luna 3 first photographed the Moon's far side, no human had ever seen it. (While they have some good guesses, astronomer's can't say for sure why this happens.)

Q: Why is the Moon sometimes white and other times orange?

A: The Moon, making no light of its own, only reflects sunlight off its drab gray surface. The apparent silvery-white comes from the brightness of the reflected sunlight against the background sky. When it looks orange--especially when its near the horizon--the color comes from our own atmosphere filtering out the bluer light, leaving the red/orange colors to pass through, sort of like looking at it through orange cellophane paper.

  • Next Two Weeks: Average sunrise: 6:17 a.m.; average sunset: 6:48 p.m. (for Waco, TX)
    * This morning the crescent Moon is to the right of Venus, and tomorrow morning below the beautiful planet.
    * The new Moon Wed., Mar. 29, produces a total solar eclipse that won't be seen from our hemisphere.
    * The evening of Apr. 1 the crescent Moon is near the Pleiades, then Apr. 3 above Mars.
    * The 1st quarter Moon is near the star Pollux Apr. 5 and near Saturn the next evening.

  • Naked-eye Planets:
    * Evening: Mars is mid way up in the west, above the reddish star Aldebaran. Saturn is high in the south, with Jupiter rising 3 hours after sunset.
    * Morning: Mercury is low in the east at dawn, well to the lower left of brilliant Venus, and Jupiter is the brightest object in the southwest.

  • Time Change: Before retiring next Saturday night, Apr. 1, set your clocks one hour ahead ("spring forward") to Daylight Time.

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March 11, 2006

You Only Think You're Sitting Still

As you read this you're probably sitting down, maybe with a cup of coffee. You feel at rest and your coffee seems motionless in its cup. It's hard to imagine, but you're actually moving thousands of miles per hour in different directions, all at once.

Once it was believed Earth was fixed at the center of creation with the Sun, Moon, planets and stars moving around it. It seemed only obvious that anyone sitting still was motionless.

But along came some trouble makers who quite literally rocked the boat. In the 1500s Copernicus theorized, then in the 1600s Galileo proved, that Earth isn't motionless--it moves around the Sun with the other planets. But this idea was heresy, and thus dangerous at a time when the church was burning people for openly disagreed with its beliefs.

Copernicus had the good sense to wait until he was on his death bed to publish his thesis, but Galileo, brilliant as he was, didn't always use good judgment. He published his findings, was put on trial and found guilty of heresy. When given the choice of burning or recanting, he publicly stated that Earth is still. But according to legend, as he left the courtroom he defiantly uttered under his breath, "And yet it does move!" But even Galileo had no idea how right he was.

Earth (along with us) moves in ways Galileo never imagined. As Earth rotates on its axis, we (at our latitude) are moving 900 miles per hour--faster than the speed of sound--as we travel 22,000 miles every 24 hours.

Yet that's a snail's pace compared to our speed as Earth circles the Sun. Each year we cover half a billion miles at 67,000 miles per hour--far faster than orbiting space craft.

But that's not all. Our entire solar system is zipping around our Milky Way galaxy at the mind-boggling speed of nearly 600,000 miles per hour in its journey of more than one quintillion miles (one followed by 18 zeros) that takes 240 million years.

And even our galaxy moves within the cosmos but since there's no fixed object against which to compare its movement, there is no way to establish its speed.

And you thought you were sitting still.

  • Next Two Weeks: Average sunrise: 6:35 a.m.; average sunset: 6:39 p.m. (for Waco, TX)
    * Tuesday's full Moon of March, called Crow Moon, Sap Moon, Lenten Moon and Egg Moon, features a slight penumbral eclipse which won't be much to see.
    * Friday morning the Moon is near the star Spica.
    * The morning of Mar. 19 the Moon is below Jupiter.
    * Mar. 20 is the spring equinox.
    * The morning of Mar. 21 the Moon is below Antares.
    * The Moon is at 3rd quarter Mar. 22.

  • 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.) Evening: Reddish Mars is high in the west, to the upper right of the equally bright reddish star Aldebaran. Saturn is high in the southeast. Morning: "Morning star" Venus is low in the southeast with Jupiter the brightest object in the southwest.

  • Public Star Party: The Central Texas Astronomical Society will host a free star party at the Waco Wetlands March 18 at 7 p.m. For directions, see www.wacowater.com/wetlands.html.

  • Astronomy Class: The Stargazer's 4-session "Learning the Night Sky" class will be Mar. 20-23 from 7:30-9:30 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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February 25, 2006

Looking for Zodiacal Light and Gegenschein

Now is good time of year to look for two ghostly spectacles that usually go unnoticed in the night sky--zodiacal light and gegenschein. Both are faint and can be seen only under clear moonless skies away from urban light pollution. They appear as subtle soft patches of lightglow with zodiacal light the much easier of the two to see. They are related phenomena yet appear in different parts of the sky and at different times.

An hour or two after sunset (or before sunrise), when the sky is totally dark, face west (or east in the morning) and look for a cone-shaped glow rising from the horizon. At the base it is about as wide as your fist held at arm's length and comes to a rounded point some two fists above the horizon. It might seem to be just a residual of dusk, but it's not. The light actually comes from beyond Earth's atmosphere in the spaces between the planets.

All the planets orbit the Sun on nearly the same plane and thus follow the same path through our sky, called the ecliptic. The band of constellations through which they pass is the zodiac, giving rise to the name, zodiacal light.

The space between the planets' orbital planes is almost empty, but not quite. It contains tiny fragments of space dust which are ordinarily invisible, like particles of household dust in the air we breathe. But when the light is just right they become visible.

Household dust can be seen as it passes through a ray of sunlight in a dimly lit room. Zodiacal light is sunlight reflected off countless particles of space dust scattered along the zodiac. Theoretically it's possible to see this faint glow along the zodiac all the way across the night sky, but in reality it's usually visible only near the horizon.

The exception is gegenschein, the part of the zodiacal light band exactly opposite the Sun. Also called counterglow, it appears as a slightly elongated patch of light best seen high in the south in the middle of the night. While zodiacal light seen near the horizon can be relatively bright, gegenschein is always much fainter and a challenge to see.

  • Next Two Weeks: Average sunrise: 6:52 a.m.; average sunset: 6:28 p.m. (for Waco, TX)
    * The Moon is new Monday, Feb. 27.
    * A thin crescent Moon is below Mercury low in the west Tuesday evening (Feb. 28) at dusk, then above the planet the next evening.
    * The Moon is to the right of the Pleiades cluster the evening of Mar. 4, then above the Pleiades and Mars the next evening.
    * The Moon is at 1st quarter Mar. 6.
    * The evening of Mar. 10 the gibbous Moon is to the upper left of Saturn with the Beehive cluster between them.

  • Naked-eye Planets: Evening: Mercury is low in the west at dusk but rapidly sinking into the setting Sun. Mars is high in the southwest and Saturn high in the southeast. Morning: "Morning star" Venus is brilliant low in the east with Jupiter the brightest object high in the south.

  • Planet-star comparison: This is a good time to test the adage "stars twinkle, planets don't" with Mars near the star Aldebaran. Both are reddish and now equally bright. They are high in the southwest in the early evening with Mars on top.

  • Astronomy Class: The Stargazer's four-session "Learning the Night Sky" class will be held Mar. 20-23 from 7:30-9:30 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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Feb. 11, 2006

Some Night Sky Coincidences

To those who take time to notice--and since you're reading this column, that probably includes you--nature abounds with wondrous and beautiful sights like flowers, sunsets, mountains, and the night sky. But not only is the night sky awesome and beautiful, it has some interesting coincidences--things with no explanation other than occurring by chance. Here's three.

The first is Polaris, a moderately bright star located nearly straight up from Earth's north pole, also called the North Star. There is no such star above Earth's south pole, and thus no South Star. But most of the time there's no North Star either.

We're aware of Earth's daily rotation (spin) on its axis, making our days and nights. But Earth also wobbles, like a toy top as its spin slows down, and as it wobbles its north pole points to different parts of the sky. Since one wobble takes 25,800 years, we hardly notice it. For only a few hundred of these years does a star as bright as Polaris comes within 1 degree of Earth's north pole, and by coincidence we happen to be living during that time.

Second is the Sun and Moon. We've all learned the Sun is vastly larger than the Moon, yet they look the same size in our sky. The diameter of the Sun is 400 times greater than that of the Moon, but--coincidence number two--it also happens to be 400 times further away, making them appear the same size.

The third coincidence is less obvious, yet accounts for some interesting night sky alignments. As Earth makes its annual revolution around the Sun, the Sun seems to go through twelve constellations known as the zodiac. Astronomers call the Sun's path the ecliptic, and since the planets orbit the Sun (and Moon circles Earth) on nearly the same plane, the planets and Moon travel close to the ecliptic in what is called the ecliptic band.

But that's not the coincidence. What's unusual is the number of other night sky objects within the ecliptic band. While the band occupies only 1/7 of the sky, nearly 1/4 of the 21 brightest stars (Aldebaran, Antares, Pollux, Regulus and Spica) are within it. And two of the three brightest star clusters (Hyades and Pleiades) are within the band. Thus the planets and Moon often pass near, and occasionally pass in front of these objects, making for some interesting stargazing.

  • Next Two Weeks: Average sunrise: 7:07 a.m.; average sunset: 6:18 p.m. (for Waco, TX)
    * This evening (Feb. 11) the Moon is below Saturn in the east.
    * Tomorrow night's full Moon of Feb. is called Snow Moon, Hunger Moon and Wolf Moon.
    * Tue. morning (Feb. 14) Venus, the Goddess of Love, is at her brightest -- on Valentine's Day, naturally!
    * Fri. evening (Feb. 17) Mars is very near the Pleiades high in the southwest, and later that evening the Moon and Spica are two moonwidths apart.
    * The morning of Feb. 20 the Moon is below Jupiter in the south.
    * The Moon is at 3rd quarter Feb. 21.
    * The morning of Feb. 24, the crescent Moon is to the right of Venus low in the east southeast before dawn.

  • 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.) Evening: Mercury, very low in west southwest at dusk, is highest above the setting Sun Feb. 24. Red Mars is high in the southwest with creamy Saturn high in the east. Morning: Venus is the "morning star" low in the east southeast. Jupiter is the brightest object high in the south.

  • Public Star Party: The Central Texas Astronomical Society will host a free public star party at the Waco Wetlands Sat., Feb. 18, at 6:30-8:30 p.m. For directions/map, see www.wacowater.com/wetlands.html.

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January 28, 2006

Clyde Tombaugh Finally On His Way to Pluto

Feb. 4 is the 100th anniversary of the birth of Clyde Tombaugh, astronomer who in 1930 discovered Pluto, and the only American to discover a planet. A year before his historic discovery, Tombaugh was an obscure 23-year-old Kansas farm boy who, as a hobby, made telescopes to view the night sky.

Armed with a high school diploma, his self-taught expertise, a strong work ethic, and love for astronomy, Tombaugh arrived at Lowell Observatory in Flagstaff, AZ, Jan. 15, 1929. The observatory was beginning a third search for a ninth planet, dubbed Planet X by the observatory's founder, Percival Lowell. Many astronomers doubted there were any more planets, and one even told the young Tombaugh he was wasting his time looking for something that didn't exist.

Yet he undertook his new job with determination. The easier part of his two-phased job was to take thousands of photos of tiny areas of the night sky, each area being photographed twice, a week apart. Even this wasn't always easy as telescopes must be at the temperature as the surrounding air, so on freezing winter nights he had to endure bitter cold to take photos.

Then using a viewing device called a "blink comparator," the more challenging part of his job was to make detailed comparisons of the pairs of photos. Over a period of a week, stars don't move relative to each other, so Tombaugh looked for objects that did move, that is, were in a different place on the two photos relative to the surrounding stars. This took not only great visual acuity but incredible perseverance and patience.

But after only a year of searching, he hit pay dirt. Feb. 18, 1930, comparing photos taken Jan. 23 & 29, he found the elusive Planet X and wrote his name in astronomical history.

In 1993 my wife and I visited with then-87-year-old Tombaugh and his wife, Patsy, in their home in Las Cruces, NM. They had not previously met us, yet were delightful and gracious hosts. Through his fame, and the professional snubs he endured in the early years, he remained renown for his humility, warmth, friendliness and humor. His love of puns is legendary. As he autographed my copy of his biography on the page with a photo of himself and his cat (named Pluto) he asked if that page was OK, and grinned as he added, "The wrong page would be cat-astrophic."

Now 76 years after Pluto's discovery, NASA, on Jan. 19, launched the New Horizons space craft on its 9 year journey to Pluto. As one of many who came to love the man, it is gratifying to know that Clyde Tombaugh, who died in 1997, is finally on his way to his beloved Pluto. New Horizons is carrying some of his ashes. He'll have to wait 9 years before reaching his tiny, remote world, but patience was one of Clyde Tombaugh's virtues.

  • Next Two Weeks: Average sunrise: 7:19 a.m.; average sunset: 6:06 p.m. (for Waco, TX)
    * From now until Feb. 9 Saturn is within two moonwidths of the Beehive star cluster (M44), coming closest Feb. 1. (This will look best in binoculars.)
    * The Moon is new tomorrow (Jan. 29).
    * Thursday (Feb. 2) is Groundhog Day, aka Candlemas, a cross-quarter day celebrating the middle of winter.
    * The evening of Feb. 5 the 1st quarter Moon is between Mars and the Pleiades.

  • 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.) Evening: Mars is high in the southwest as Saturn is rising in the east. Morning: Jupiter, up by 2 a.m., is high in the south southeast while Venus rises an hour and a half before the Sun.

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January 14, 2006

Night Sky Highlights for 2006

As in most years, 2006's best night sky events will involve the five naked-eye planets. Mercury is in the evening sky in February, June and October, and morning sky in April, August and November. Venus is the "morning star" most of the year. Mars is in the evening sky through early summer. Jupiter, now in the morning sky, is up all night during spring and in the evening sky through fall. Saturn, now at its best, is in the evening sky through early summer, moving into the morning sky in early fall.

While just seeing the planets can be a thrill, there will be some close encounters you won't want to miss. Venus passes Uranus in April, the Pleiades star cluster in June, the Hyades cluster and star Aldebaran in July, Gemini's M35 cluster in July, and Mercury in August.

Mars visits the Pleiades in February, M35 in April, Saturn and the Beehive in June, and Regulus in July. Saturn spends the year near the beautiful Beehive cluster, coming closest in late January-early February and again early June. Jupiter spends the year near Libra's brightest star, Zubenelgenubi, a binocular double star, passing nearest in January, May, and September.

The gathering of the year comes the evening of June 27 when a thin crescent Moon joins Mercury, Saturn, Mars and the Beehive low in the west soon after dusk.

Meteor showers favored this year by moonless skies are April's Lyrids, May's Eta Aquarids, October's Orionids, November's Leonids, and December's Geminids and Ursids. It will not be a good year August's favorites, the Perseids.

Comet 73P Schwassmann-Wachmann 3 could become naked-eye visible in May--if it still exists. The comet broke into several pieces in 1995 and might have fragmented in 2001. But if its largest component is still intact, it will pass nearer Earth than ever before and could be interesting. No other known bright comets are expected in 2006, but there's always the possibility of newly-discovered ones bursting on the scene.

The late afternoon of Nov. 8 Mercury will transit (pass in front of) the Sun, something to be viewing only through a properly filtered telescope. Our part of the world won't see any good solar or lunar eclipses this year. Finally, the Stargazer's Learning the Night Sky classes will be Mar. 20-23 and Oct. 9-12. Hope you'll plan to join us.

  • Next Two Weeks: Average sunrise: 7:27 a.m.; average sunset: 5:53 p.m. (for Waco, TX)
    * This evening's (Jan. 14) full Moon, called Old Moon, Cold Moon, and Moon After Yule, is near Saturn all night.
    * Late Monday evening (Jan. 16) the Moon is near the star Regulus.
    * The Moon is at 3rd quarter Jan. 22.
    * The Moon is to the right of Jupiter the morning of Jan. 23.
    * The Moon is within a moonwidth of the star Antares the next morning, Jan. 24.

  • 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.) Mars, still brighter than most stars, is high in the southwest in the evening. Saturn rises soon after sunset and is up all night. Jupiter is in the southeast in the morning.

  • Telescope Session: The Central Texas Astronomical Society's annual Learn to Use Your Telescope session will be held at Hewitt City Park Jan. 21 starting at 5 p.m. Bring your telescope for free hands-on instruction.

  • Space Exploration: The Stardust spacecraft is due back tomorrow (Jan. 15) from its Comet Wild 2 encounter. New Horizons is due to be launched Jan. 17 en route to Pluto.

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