Comet comes close to Earth Fri., June 29, 2001 2:30 p.m. ET

Lucas J. Mire, weather.com Amateur astronomers or just plain 'ole stargazers will have a unique opportunity to watch a comet streak across the sky this weekend. Comet LINEAR will make its closest appraoch to Earth on Saturday and be visible to the naked eye to those in the Northern Hemisphere.

Why is this comet able to be seen without the help of a telescope?

"It's pretty close," explained James F. Bell III , Ph.d., assistant professor of astronomy at Cornell University's space sciences program. "It's only about 20 million miles away, which is close in terms of the solar system."

What is a comet? "A comet is basically a dirty snowball," says astronomy professor James F. Bell III, Ph.d. "Comets themselves are small little objects, sometimes only a kilometer in diameter, made of water-ice, rock and other kinds of ice: dry ice, carbon monoxide-ice, depending on where they were born in the solar system. When the comet gets closer to the sun, the ices get burned off. The big tail is the icy, rocky debris being shed off this tiny little object."

Bell says the comet, which is actually a "dirty snowball made up of water-ice, rocks and other types of ice," will be visible before sunrise on Saturday and a few days afterward.

"Maybe an hour or two before the sun rises, you'll be able to see it," he said. "You can find the comet by looking in the direction of Venus. It's quite a spectacular show for such a small object."

According to NASA, Astronomers have watched comet LINEAR intently in recent months, as it continued to crumble and brighten. Armchair astronomers may find the phenomenon noteworthy because it happens so infrequently.

"It's relatively rare," explained Bell. "We had [a comet] in 1996 and another in 1997, which you may remember as Hale-Bopp. It was much larger than the current comet and it got very bright because it got so close to the earth. This is the best one since those two comets."

But will Bell and his children be up early for the event?

"I'll try to get them up, but to them it's just Dad's job, so it's not as exciting."

http://www.weather.com/newscenter/topstories/010629spacecometlinear.html

-- Martin Thompson (mthom1927@aol.com), June 29, 2001

Answers

Thanks for the submit Martin, I'm slowing down on the beers, so I can get up, and dusting off my little telescope for tomorrow morning's show.

-- Doris (nocents@bellsouth.net), June 29, 2001.

Sky and Telescope

Java 3-D Orbit

-- spider (spider0@usa.net), June 29, 2001.

Via automatic alert generated by spaceweather@lists.spaceweather.com

"Space Weather News for June 28, 2001

http://www.spaceweather.com

NAKED-EYE COMET: Comet C/2001 A2 (better known as "Comet LINEAR") makes its closest approach to Earth on Saturday, June 30th. Glowing at visual magnitude 4, Comet LINEAR is not spectacular like, e.g., Comet Hale-Bopp of 1997, but it will be easy to spot with the unaided eye. Astronomers have watched this comet intently in recent months as it repeatedly crumbled and brightened. The capricious snowball from the outer solar system could yet hold surprises for observers in the days and weeks ahead.

Visit SpaceWeather.com for finder charts and more information."

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Andre note: you'll have to get up pretty early (stay up late?) to see this, around 3 or 4 AM for Northern temperate locations where most people live. Pretty enough, but some people will be disappointed if they expect rapidly moving bright lights, per Hollywood -- this is more an intellectual thrill.

Also don't miss Mars, that really bright orange dot near the southern horizon at midnight (visible most of the evening, actually) which is currently at its closest approach. In even a small telescope on a decent night, large Mars surface features are visible.

-- Andre Weltman (aweltman@state.pa.us), July 02, 2001.