HELLO, HYAKUTAKE\'Great Comet of 1996' nears Earth.

Byline: Tony Knight Daily News Staff Writer

A big ball of ice and dirt that astronomers already are calling the "Great Comet of 1996" is heading toward a close pass with Earth next week, but earthlings won't have to wait another day to see it.

Comet Hyakutake already can be seen with the unaided eye looming faintly above the horizon in the southwest, astronomers with the Griffith Observatory said Monday.

The comet could be the brightest to pass Earth in 20 years and could sprout a tail by late April that stretches a quarter of the way across the sky, astronomers said.

"It already is brighter than any comet in the last 10 years," said Anthony Cook, a comet expert at Griffith. "Halley's comet was the last comet that was bright. This should exceed the brightest that Halley's was at its best."

Astronomers who have been tracking the comet's approach using binoculars say the sight is spectacular already, and the object is being hailed as the Great Comet of 1996 in conversations on the Internet.

"I've seen it with the naked eye from Reseda," said Griffith astronomer John Mosely. "With binoculars it's really quite easy to see."

The Griffith Observatory is planning a special show on comets that will begin tonight and will run through next week. Cook will give a special talk on the new comet Monday night. And the public is invited to comet-watching sessions at the observatory nightly beginning Friday.

The best place to view the comet, discovered Jan. 30 by amateur Japanese astronomer Yuji Hyakutake, is away from city lights in the mountains or desert, experts say. The best time for a first good look is between midnight today and 3 a.m. Wednesday.

Astronomers said to look low in the southwest for a fuzzy blob about the size of the full moon.

"You don't see the nucleus at all, that's shrouded in a cloud of evaporating ice and dust," Mosley said. "What you do see is the coma or the head, and that's a mixture of dust and gas that is on the order of 100,000 miles across."

Although it is as large as the full moon, the comet is very faint and might be completely washed out by city lights, Mosley said. The darker the sky, the better chance of seeing the comet, he said.

The comet will climb higher and higher on each succeeding night and move from southwest to northeast, remaining in the northeastern sky after dusk through late April.

By this weekend, Hyakutake will rise well before midnight, and during its closest approach Monday and March 26, it will stay in the sky all night.

Some astronomers said good nights for viewing, weather permitting, will be Thursday and Friday nights this week when the comet can be seen almost overhead near the very bright star Arcturus.

To find Arcturus, extend the "arc" of the handle of the Big Dipper to the first very bright star, astronomers advised.

Cook said he is hoping the comet will be showing a bright tail during its closest approach to Earth on Monday and March 26. On those nights it will be about 9-1/2 million miles from Earth.

"I think the most comfortable way to view it when the comet is at its closest to the Earth is to go out after the moon sets, around midnight or a little after," said Cook. "Get out in a chaise lounge or something comfortable and look toward the Big Dipper."

Comets are balls of ice and dirt that circuit the sun in elongated orbits that take them to the outer reaches of the solar system. As they approach the sun, they sprout long tails caused by the pressure of solar radiation driving particles away from the comet's head.

Comets can be extremely large and bright objects likeComet West, which passed Earth in 1976 and had a very bright tail that stretched about one-fourth of the way across the sky.

"Some people even saw it in bright daylight," Cook said of Comet West.

He said Hyakutake doesn't really have a bright tail yet, but a slight tail can be seen through binoculars.

"There is a possibility that after it passes the Earth and continues getting closer to the sun, the dust tail will lengthen and also brighten," Cook said. "So the tail might stand out against even a twilight sky towards the end of April. That remains to be seen, though."

For more information on Griffith Observatory programs featuring the comet, call the observatory's Comet Hotline at [phone]. For operating hours and planetarium information, call [phone].

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Photo no caption (route of Comet Hyakutake across the night sky)