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- From: parish@cactus.org (Tom Parish)
- Subject: Skywatch from McDonald Observatory - Moved to sci.astro
- Message-ID: <1992Nov22.171736.26482@cactus.org>
- Organization: Capital Area Central Texas UNIX Society, Austin, Tx
- Date: Sun, 22 Nov 1992 17:17:36 GMT
- Lines: 117
-
- I'll post another issue for Nov 29-Dec 5 however, a number of folks
- suggested I put Skywatch on sci.astro. It doesn't really make any
- difference to me. Take care and enjoy the holidays (if you are
- in the states).
-
- Tom Parish
- ------------------------------------------------------------------
- Star Date Turning Point
-
- SKYWATCH
- November 29-December 5
-
- An Asteroid Approaches Earth
- by Jeff Kanipe
- Editor of Star Date Magazine
-
-
- PLANETS
-
- * Mercury is very low in the southeast just before sunrise. It is
- more visible later in the month.
-
- * Venus is the bright "evening star" in the west after sunset. It
- sets about three hours after sunset.
-
- * Mars rises 3 hours after sunset in the constellation Gemini.
-
- * Jupiter rises just after midnight in Virgo.
-
- * Saturn is in the south at sunset in Capricornus. It sets about
- midnight.
-
- EVENTS
-
- Nov. 30: Saturn is just south of the crescent moon this evening.
-
- Dec. 1: The moon is at apogee, 405,070 km (251,698 mi).
-
- Dec. 2: First quarter moon.
-
-
- TOUTATIS: PROTECTOR OF THE TRIBE
- --------------------------------
-
- The 4-mile-wide asteroid Toutatis will pass within 2.5 million
- miles of Earth the morning of December 8, a distance ten times
- that between Earth and the moon. Toutatis is the closest
- encounter we have had with a celestial body other than the moon
- that has been predicted far in advance (its orbit was determined
- in January 1989). Astronomers discovered that Toutatis has an
- orbit very much like a short-period comet, that is, it describes
- a path through the solar system that is more stretched-out than
- a simple elliptical orbit.
-
- Toutatis was named after the Gallic god, the "protector of the
- tribe." Gauls, whose religious leaders were Druids, believed
- Toutatis prevented the sky from falling on them!
-
- Toutatis is classified as an Apollo asteroid, one of about 100
- known asteroids that actually cross Earth's orbit periodically.
- Its comet-like orbit may be due to the gravitational sling-shot
- effect of the planet Jupiter. At one time, Toutatis may have
- been an ordinary asteroid. But then during a close passage to
- Jupiter, the huge planet may have managed to impart some of its
- gravitational energy to the asteroid and, like a mean game of
- crack- the-whip, accelerated the asteroid toward the inner solar
- system--and us.
-
- Next week, Toutatis will be five times closer than it was in
- 1989. Astronomer Art Whipple of the University of Texas at
- Austin McDonald Observatory calculates the asteroid's closest
- approach will occur December 8. Toutatis will be brightest,
- however, the morning of December 12. Observers with small
- telescopes won't see much: a very faint, tiny point of light
- among hundreds of other points of light-- stars--about 12 degrees
- south- southeast of the bright star Regulus in the constellation
- Leo. (Twelve degrees is slightly greater than the area of sky
- covered by the typical fist held at arm's length.) If you watch
- carefully over a period of about fifteen or
-
- twenty minutes, though, you may see one of the stars move
- slightly with respect to the background stars. That will be
- Toutatis.
-
- Toutatis passes Earth quickly, but returns in September 2004,
- when it will come with 966,000 miles of Earth, just four times
- the Earth-moon distance.
-
- Astronomers estimate there may be more than 1,000 Toutatis-like
- asteroids more than a half-mile in diameter shuttling unnoticed
- across Earth's orbit. And indeed, in the last few years, more of
- these Earth- crossers have been discovered by patrol cameras.
- But not to worry. Our home planet is a very small target in a
- very large universe. The odds of Earth being struck are quite
- (pardon the pun) astronomical.
-
-
- ----------------------------------------------------------------
-
- Jeff Kanipe is editor of Star Date Magazine, published by
- McDonald Observatory at the University of Texas at Austin. Write
- to Star Date at 2601 University, Room 102, the University of
- Texas at Austin, Austin, TX 78712 for subscription information.
- It is very reasonable in cost, informative and colorful.
-
- Copyright 1992 The University of Texas McDonald Observatory.
- Material is intended for personal education and should not
- be rebroadcast in any written or verbal form without
- prior permission from the University of Texas.
-
- ----------------------------------------------------------------
-
- Also see the daily scripts from the Star Date
- Radio Program on the Turning Point.
- HST/DS 512-219-7848
- .
-
-