Comet Hartley proving elusive

Wednesday, November 24, 2010

At the time of this writing, I still haven't put glass on Comet Hartley. Sometimes that is just the way it goes for astronomers, and comets are notorious for being elusive.

I have maps, star charts, and locator guides, but still no comet. Oh well, there is always tomorrow morning -- unless it is cloudy.

November has been an interesting month astronomically speaking and December promises be even more interesting.

Saturn and Venus have returned to the morning sky. About an hour to an hour and a half before sunrise, they can be viewed in the east just above the horizon for all you farm folks doing morning chores.

Venus can't be missed for its brightness and dimmer Saturn is just above and slightly right of it. The bright star Spica, the brightest star in Virgo is between them.

Speaking of comets, this one will be easy. Comet Ilkeya-Murakarmi is about four degrees above Venus in the morning sky. It will be moving closer to the planet each day until Dec. 8, when it will pass the bright planet on the right. Good binocular target as they both will be in the same field of view.

In the evening sky, Jupiter still holds sway although it is moving closer each day to the due south marker meaning it will be in the sky less and less each night.

Jupiter and Uranus can still be viewed in the same binocular field of view but the smaller gas giant is moving closer to the extreme opposite edge each night. With bright Jupiter on the right edge of your view field dimmer Uranus will be on the exact opposite side.

One thing to be aware of, the star 20 Piscium is between them shining almost as bright as the smaller gas giant.

At present Jupiter is traveling in what is called "retrograde motion." That means as compared to the background stars Jupiter appears to travel against the direction is usually travels in its orbit, which is eastward.

The optical illusion happens because Earth is catching up with Jupiter and will soon pass it on the inside orbital track. When that happens the outer object appears to travel backward.

Kind of like when you pass a car on the highway, as you are passing, the other vehicle appears to be traveling backward. That backward motion for Jupiter is about to end and it will assume its normal path compared to the background stars.

That also means Jupiter and Uranus will be coming closer together. The pair will pass on or about Dec. 31. They would make a good object to look for on New Year's Eve.

How about a look ahead for December. Circle Tuesday, Dec. 21. There will be a total lunar eclipse visible from this area. More as the date draws closer.

SKY WATCH: The moon was full last Sunday, Nov. 21, which means it will be rising today (Wednesday, Nov. 24) at about 8:30 which will give us a short time for any observations we would like to make. Here is a challenge for you. Between now and Dec. 12, the fleet-footed planet Mercury will be making a very brief showing in the west just after sunset. Why not try to find the elusive smallest planet during those days. Try about a half-hour after sunset and please emphasize the after part. Binoculars will come in very handy. Just be very careful. If you are looking while the sun is still in the sky keep your observation sweeps well away from it. Even a very small, fraction of a second of solar observing in binoculars will be the last thing you will see, ever.

NEXT WEEK: More astronomical blathering.

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