March 24, 2007
Stargazer #449
Farewell to Orion and the Winter Arc
It's the beginning of spring and time to bid ado to Orion and the Great Winter Arc, now nearing the western horizon in the early evening.
Orion the Hunter, along with his adversary, Taurus the Bull, dominates the early evening sky from December through February, and together are the centerpiece of the Great Winter Arc region. Because of the abundance of bright stars, this region outshines all other regions.
Of the 21 brightest stars -- called 1st-magnitude stars -- only 16 are ever visible from our mid-northern latitude, and seven are in the Great Winter Arc region.
Orion has two -- red giant Betelgeuse (top) and white Rigel (bottom). Aldebaran, the red eye of Taurus, is also a red giant.
Red giants are geriatric stars in the latter stage of their life. As stars begin depleting their fuel, they swell into enormous cooler, redder giant stars before collapsing into stellar death. Check back in a million years or so and stars like Betelgeuse, Aldebaran and Scorpius' Antares may well have died.
The winter arc, like a dome covering the hunter and the bull, contains the region's remaining four 1st-magnitude stars. At the left (east) end the arc starts with Sirius, the night sky's brightest star, then proceeds to Procyon to the upper right. High at the top of the arc is Pollux, and its almost-1st-magnitude mate, Castor, the heads of the Gemini twins. To the lower right, the arc ends at Capella, a yellowish star much like our Sun.
So this evening, while they're still hanging around, go out and tell our winter companions adios until next winter. And while you're at it, say hello to Venus below Taurus' Pleiades cluster.
- Next Two Weeks. Ave. sunrise: 7:19 a.m.; ave. sunset: 7:47 p.m. (for Waco, TX)
* The Moon is at 1st quarter tomorrow.
* Wednesday evening it passes just above Saturn high in the south, and the next evening is just above Leo's brightest star Regulus.
* The April 2 full Moon is called Grass Moon and Egg 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: Venus, the dazzling "evening star," is hard to miss in the west while creamy-colored Saturn is high in the south.
Morning: An hour before sunrise Mercury is barely above the eastern horizon with Mars a hand span to its upper right. Jupiter outshines everything else mid way up in the south.
March 10, 2007
Stargazer #448
The Stargazer and UFOs?
So what's with the Stargazer and UFOs? That's what some folks were wondering after my last column, offered as a sci fi mini-short story. It seemed to amuse some, confuse others and maybe even bother some. (See last column below.)
It certainly wasn't intended to confuse or worry. Entertain and amuse? Sure. But I hoped to stimulate thinking, and maybe I did.
Some wondered if I'd really been abducted and examined by aliens, or thought I had. A couple of friends suggested it would have been good for April Fool's Day, and it would have had it been scheduled to appear Apr. 1.
So, as some asked, do I or don't I believe in UFOs? The answer is a definite yes...and a pretty definite no. So how can that be?
We have yet to find one shred of evidence, still I think it's just a matter of time--maybe soon, maybe a long time--until we discover we're far from alone. I suspect the cosmos, and even our Milky Way galaxy, is teeming with life, some far more advanced than we are. So, yes, I definitely believe "they are out there."
But, as much as I want to believe it, I seriously doubt Earth has been visited by aliens. Back when Apollo astronauts were walking on the Moon, Erich von Daniken wrote "Chariots of the Gods?" offering what he considered evidence that Earth has been visited by ancient astronauts. As one long fascinated with space travel, starting with the movie "Rocketship X-M" and then "Star Trek" and "Star Wars," I fervently hoped he was on to something. But as scientific-appearing as his arguments appear on the surface, they just don't hold up to more critical scrutiny.
Sure, it's possible aliens have visited Earth, and maybe they're monitoring us right now. But it's just so utterly unlikely considering the vast distances between stars within galaxies, and the inconceivable immenseness of space between galaxies. With our current understandings of the laws of nature, especially the seemingly insurmountable speed of light, travel and even communication between cosmic civilizations seem next to impossible.
But then to our cave-dwelling ancestors, humans walking on the Moon must have seemed equally preposterous. So, who knows?
In the meantime, I would hope things like my "what if" science fiction piece might further our thinking about how we can--and better--start taking more responsibility for our own future, utilizing our abilities to think, anticipate consequences, plan and exercise considerable control over our own species' destiny.
- Next Two Weeks. Average sunrise: 7:36 a.m.; average sunset: 7:38 p.m. (Daylight Times) [for Waco, TX]
* Tonight, Mar. 10, before retiring set your clocks up one hour ("spring forward") to Daylight Time--yes, it starts earlier now.
* Tomorrow morning's 3rd quarter Moon is to the lower left of Antares in the south with bright Jupiter to their left.
* Thursday morning the crescent Moon is to the upper right of Mars low in east, then the next morning below it.
* The Mar. 18 new Moon produces a partial solar eclipse that won't be visible in the U.S.
* Mar. 20 is the first day of spring.
* The evening of Mar. 22 the crescent Moon is below the Pleiades star cluster in the west after dark.
- Naked-eye Planets. EVENING: "Evening star" Venus is in the west with Saturn midway up in the east. MORNING: Mercury is just above the eastern horizon at dawn with Mars a handspan to its upper right and Jupiter the brightest object in the south.
- Star Party. The Central Texas Astronomical Society's monthly public star party at the Waco Wetlands is tonight, Saturday, Mar. 10, beginning at 7 p.m. An indoor program is followed by outdoor viewing. For directions see www.wacowater.com/wetlands.html.
February 24, 2007
Stargazer #447
Earth Report
Not being a believer in UFOs, the other night I was stunned to find myself in a totally inexplicable situation. While under the stars with my telescope I was momentarily blinded by a flash of light, and then discovered myself to be in an utterly alien place, surrounded by beings who looked like nothing I'd ever seen or imagined. I can't even describe them – they were just there.
As I stood in disbelief, wondering if I was dreaming, they passed a strange scanning device over me several times. They made no audible sounds, yet clearly were communicating with each other, maybe telepathically or at a frequency beyond my hearing. I felt no discomfort – in fact I felt nothing – strangely enough, not even fear or anxiety.
After a few minutes they began speaking to me in a voice that sounded just like my own. I say spoke, but they had no mouth and nothing moved, yet I clearly heard and understood them, and they heard and understood me.
The visitors said they were part of an intergalactic exploratory team on a survey mission, and were currently updating their records on Earth. Their commission monitors several million sites in our sector of the cosmos, including thousands in our own Milky Way galaxy, where life exists, focusing most closely on places where intelligent civilization has or is evolving.
You can imagine my shock when they matter-of-factly said Earth is not yet on the “Civilized” list. They've been monitoring our planet from afar for millions of Earth-years, and only some 100,000 years ago were we moved from the “Primitive” to the “Evolving Civilization” list. They were encouraged with the rate at which our intelligence was evolving, but were concerned about the development of our “collective maturity,” something, they said, over which we have control. Their surveys have shown that species need both in order to survive long enough to become part of the intergalactic community.
I must have looked puzzled so they elaborated as best they could within the limits of our language, citing things like accrued wisdom, rational ethics, compassion, justice, altruistic self-interest, and they even pointed to our “golden rule” and Kant’s “categorical imperative” as encouraging starting points. Intelligent civilizations, it seems, emerge when a critical mass of the dominant species develops the capacity for being, on the one hand, dreamers, idealists and visionaries, and, on the other, realists who recognize the pitfalls of irrational, superstitious and magical thinking.
Before long the visitors sensed that my mind was becoming overloaded, and as quickly as they appeared, they vanished, leaving me alone with my telescope.
My memory is so sketchy – if only I could have recorded what they said, or even taken notes. So, dear readers and fellow-Earthlings, help me remember – what else might the visitors have told me?
- Next Two Weeks. Average sunrise: 6:53 a.m.; average sunset: 6:28 p.m. (for Waco, TX)
* The Moon is at 1st quarter today.
* Friday evening the Moon is to the left of Saturn.
* The Mar. 3 full Moon, called Sap Moon, Crow Moon, Lenten Moon, is below Regulus; there will also be a total lunar eclipse, but it is mostly over when the Moon rises over Texas around 6:30 p.m.
- Naked-eye Planets. Evening: Brilliant Venus is in the west with creamy-colored Saturn in the east. Morning: Reddish Mars is low in the east with bright Jupiter higher in the south and Saturn low in the west.
February 10, 2007
Stargazer #446
New Horizons and Gravity Assist
It was just a year ago, on Jan. 19, 2006, that NASA launched New Horizons on its 9-year journey to Pluto and beyond. Already the speedy spacecraft is nearing Jupiter, over 400 million miles from Earth.
Never has anything human-made traveled so fast, and its speed is increasing--but more about that in a moment. By comparison, the Galileo craft, launched in 1989 to study Jupiter, took over 6 years to reach the planet. New Horizons will take just over 13 months, passing our largest planet on Feb. 28.
Traveling at the incredible speed of 43,000 miles per hour, it covers more than a million miles a day--like two daily round-trips to the Moon. But even at that speed it would take 12 years to reach Pluto. The Jupiter fly-by will increase the spacecraft's speed to 52,000 mph, getting it there 3 years earlier.
The 20-percent increase in speed will result from a maneuver called "gravity assist," taking advantage of huge Jupiter's enormous gravitation pull. Even now as the craft is approaching the planet, its speed is increasing so that it will reach Jupiter traveling 47,000 mph. It's as if it is falling toward the planet, picking up speed as it falls. Its path will take it near, but not let it fall into, the planet.
Now you might be thinking ahead and wondering: after it passes Jupiter, won't the planet's gravitational pull then work to decrease the spacecraft's speed as it pulls away? Indeed it would, if not for the fact that Jupiter itself is traveling 29,000 mph as it orbits the Sun. The direction from which New Horizons approaches Jupiter takes advantage of the planet's speed and let's Jupiter "sling" it away at an even faster pace.
An analogy might help. Throw a tennis ball against a wall and it bounces back at about the same speed it was thrown. But throw it against the front of an on-coming train and it will bounce back much faster than it was thrown, picking up additional speed from the motion of the train.
So thanks to gravity assist from Jupiter, New Horizons will reach Pluto in 2015, and I can't wait.
- Next Two Weeks. Average sunrise: 7:08 a.m.; average sunset: 6:17 p.m. (for Waco, TX)
* Tonight the Moon is at 3rd quarter and Saturn is at opposition, rising at sunset and staying up all night.
* Monday morning the Moon, Antares and Jupiter form a triangle with bright Jupiter to the upper left and the star to the upper right.
* Monday evening an hour after sunset look for brilliant Venus low in the west with Mercury to its lower right just above the horizon.
* Wednesday morning a thin crescent Moon is to the right of Mars near the eastern horizon an hour before sunrise.
* The Moon is new Feb. 17.
* The evening of Feb. 19 will feature a beautiful sight when a crescent Moon is above Venus low in the west at dusk.
- Naked-eye Planets. The evening sky hosts Venus and Mercury in the west and Saturn in the east. Morning stargazers see Mars low in the southeast, much brighter Jupiter to its upper right, and Saturn low in the west.
- Star Party. The Central Texas Astronomical Society's free monthly Waco Wetlands star party is tonight beginning at 7 p.m. There will be an indoor program if it's cloudy. For directions, see www.wacowater.com/wetlands.html.
- Astro Milestones.
* Feb. 15 is the 443rd birthday of Italian astronomer Galileo Galilei (1564-1642).
* Feb. 18 is the 77th anniversary of Clyde Tombaugh’s 1930 discovery of Pluto from Lowell Observatory in Flagstaff, AZ.
* Feb. 19 is the 534th birthday of Polish astronomer Nicolaus Copernicus (1473-1543).
January 27, 2007
Stargazer #445
Using Venus to Find Uranus
Have you ever seen the planet Uranus – not just a picture, but the real thing? Probably not, but you can change that the evening of Feb. 7 using the easy-to-find Venus as your tour guide. And while you’re at it you can spot Mercury, another elusive planet most people have never seen.
With a diameter four times that of Earth, Uranus is huge, but it’s also distant, making it difficult to see. It’s nearly 2 billion miles from the Sun, twice the distance of Saturn.
Being a gas planet, no astronaut will ever stand on Uranus, yet someday one will surely stand upon one of its moons. And when that astronaut looks back toward our Sun, she or he will see only an unusually bright star -- not the blindingly bright small disk we see from Earth.
Planets don't make light -- they only reflect sunlight. At Uranus’ vast distance not much sunlight reaches it, thus it shines so faintly it is generally not visible to naked eyes as seen from Earth.
So break out your binoculars, or borrow a pair from a friend, and get ready for a new experience. Once you've seen Uranus, you'll join the tiny fraction of humans who have ever viewed our distant solar system neighbor which wasn't discovered until 1781.
Feb. 7, an hour after sunset, face west where the Sun went down. Venus easily outshines everything else at about 10 degrees above the horizon – the width of your fist held at arm’s length. Most binoculars have a field of view of about 7-degrees, so place Venus near the top of the field. Uranus, looking like a faint, possibly bluish tinted star, will be just to Venus’ right. Below Uranus will be a star, Lambda Aquarii, a bit brighter and perhaps appearing slightly reddish.
Further to the lower right, near the bottom of the field, look for Mercury, appearing brighter than Uranus and the star but not nearly as bright as Venus. Situated about half way between Venus and the horizon, Mercury might be visible without binoculars. Tiny Mercury is not much larger than our Moon yet it far outshines the much larger Uranus because, as the innermost planet, it is nearer the Sun and nearer to us.
Once you've spotted Uranus and Mercury, you can check them on your stargazing life list, but don't wait too late as they set 2 hours after sundown.
- Next Two Weeks. Average sunrise: 7:20 a.m.; average sunset: 6:05 p.m. (for Waco, TX)
* Friday (Feb. 2) is Groundhog Day, also known as Candlemas, a cross-quarter day celebrating the middle of winter.
* Friday evening January’s full Moon, called Wolf Moon, Snow Moon, and Hunger Moon, is below Saturn as they rise just after sunset.
* The Moon is at 3rd quarter Feb. 9.
- 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.) The early evening features Venus, the brilliant “evening star” in the west with Mercury below it; each evening Mercury climbs a bit closer to Venus, but never quite reaches it, coming closest Feb. 4. Saturn rises soon after sunset. Morning stargazers see Saturn setting in the west with Mars rising in the east southeast with brighter Jupiter higher in the southeast.
- Astro Milestones. Feb. 4 is the 101st anniversary of the birth of American astronomer Clyde Tombaugh (1906-1997), discoverer of Pluto.
January 13, 2007
Stargazer #444
Night Sky Highlights for 2007
Once more it’s time to preview the coming year’s night sky highlights.
Prominent Planets: Venus is the “evening star” through summer and becomes the “morning star” in early fall. Jupiter, now seen in the morning, will dominate the evening sky spring through late fall.
Saturn, in the evening sky through June, moves into the morning in early fall. Mars spends most of the year in the morning sky, moving into the evening by fall and reaching opposition (closest and brightest for this appearance) in latter December.
views coming in July and early November.
Meteor Showers: This best meteor showers should be the Perseid in August and Geminid in December. Other showers of interest could be the Lyrid (April), Draconid and Orionid (October), Taurid and Leonid (November).
Eclipses: There will be a total lunar eclipse in March and in August, the latter being better positioned for viewing from Texas. Two partial solar eclipses won’t be visible from the U.S.
Other: The crescent Moon and Venus frequently pair up to provide spectacular beauty as will occur the early evening of Jan. 20 and several more times throughout the year. And there will be other pairings, groupings and “close encounters” involving the Moon, the naked-eye planets, dazzling star clusters and some bright stars.
The morning of Nov. 3 the Moon occults (passes in front of) the star Regulus, hiding it for about an hour.
Things to Do: Consider joining the Central Texas Astronomical Society and meet other stargazers. Beginners, with or without scopes, are welcome as are experienced observers. Even if you don’t wish to join, you’re welcome to attend CTAS’s free, public star parties held each month at the Waco Wetlands in cooperation with the City of Waco. See CTAS’s website (www.centexastronomy.org) for membership information and star party dates.
If you don't live in Waco or Central Texas, many areas have regular or periodic free, public star parties sponsored by local astronomy clubs. To find a club in your area see www.skyandtelescope.com (Community – Clubs & Organizations). Then contact the club for a schedule of their events.
The Texas Star Party, the premier amateur astronomy event in the southwest, is May 13-20 in Ft. Davis, TX, a few miles from McDonald Observatory. See www.texasstarparty.org.
- Next Two Weeks. Average sunrise: 7:27 a.m.; sunset: 5:52 p.m. (exact for for Waco, TX)
* Monday morning (Jan. 15) just before dawn the crescent Moon passes less than two moonwidths to the right of Antares low in the southeast with bright Jupiter to their upper left.
* The next morning, a thinner crescent Moon is just above the horizon with Mars rising to its lower left and Jupiter higher above.
* The Moon is new Thursday, Jan. 18.
* The evening of Jan. 20 a thin crescent Moon is above Venus low in the southwest at dark.
* The Moon is at 3rd quarter Jan. 25.
- 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 stargazers can’t miss “evening star” Venus climbing higher each night. Saturn rises a little after Venus sets, and by month’s end Mercury is visible low in the west at dusk. Morning stargazers see Mars low in the southeast at dawn, well below much brighter Jupiter, and Saturn high in the west.
- Stargazer Anniversary. Stargazer begins its 18th year. Your continued readership is appreciated, as are your emails and calls.
