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. Last Updated: 07/27/2016

Hyakutake's Trip Dazzles Astronomers

Speeding toward the sun at 38 kilometers per second, the brightest comet to be seen from earth in the last 20 years is amazing astronomers with a tail that erupts in geysers of dust and vapors and stretches across a 16 million kilometer swath of the universe.


"It's magnificent," Patrick Palmer, an astronomer at the University of Chicago, said in a telephone interview. "It's a tremendous comet with a great tail across the sky."


Seen from earth, Hyakutake, otherwise known as C/1996 B2, was at its brightest March 25 when at 10 a.m. Moscow time it came within a mere 15 million kilometers of the planet. It is the fifth closest to earth that a comet has come in this century.


Since then it has been whizzing toward the sun, and while the nucleus has been fading with distance, Hyakutake's tail is emitting a spray of gases that becomes more and more spectacular as the comet approaches the sun's heat.


In the Northern Hemisphere, on clear nights and in rural areas away from artificial lights, it should be visible to the naked eye until mid-April. Its white streak of light is considered one of the most impressive this century.


Easily recognizable as a bright and fuzzy dot, which Wednesday will be seen to the left of the constellation Cassiopeia and to the right of Perseus, Hyakutake will move closer to the horizon toward the end of the month.


On May 1, Hyakutake will reach its closest point to the sun, passing within 34 million kilometers, before heading away and becoming visible only from the Southern Hemisphere.


While Hyakutake has fascinated astronomers all over the world, it has also been the subject of much interest to observers of celestial influences on human affairs.


To Vladimir Kopylov, of the Russian Astrology Society, it is not by chance that the comet has been spotted in a year of elections and significant political change.


"From an astrological point of view what's important is that the planet was discovered in the sign of Scorpio which is linked with what is past, what has died and what mankind has consciously or unconsciously discarded," Kopylov said. "I think this is a reminder that we have thrown away too much of the past and that we should have kept some of the positive things today," he said.


Kopylov said the comet's appearance in Scorpio, a water sign, was an indication of floods. Other predictions for the Northern Hemisphere involving the comet, he said, included earthquakes, political cataclysms, serious changes in government policy and a surge of terrorism and anarchy.


But because comets herald change, he said he believed the war in Chechnya would soon come to an end.


"As Hyakutake gets closer to the sun we can predict a lull [on behalf of the opposition] and relative invisibility of opposition forces behind the figure of the president," Kopylov said. "Struggles behind the scenes will play a much stronger role."


The astrologer added that Yeltsin should take extra cautionary measures, especially regarding his health and security because the comet's approach to the sun was often associated with the health of leaders.


While Palmer said Hyakutake last visited the inner solar system about 10,000 years ago, scientists have predicted that because of the sun's gravitational influence on its path, it probably will not return for a much longer period.


"The comet will return to the inner solar system in approximately 14,000 years," said Donald Yeomans, a senior research scientist at the Jet Propulsion Laboratory, or JPL, in Pasadena, California.


Discovered Jan. 30 by the Japanese amateur astronomer after whom it was named, Hyakutake has stunned observers with more than just its looks.


Unlike planets and stars, the comet has barely evolved in the 4.5 billion years since the creation of the solar system. As such, it is a time capsule that could provide crucial information on the origins of the universe.


"The present-day study of comets gives scientists a view as to what conditions were like when the earth and outer planets were just beginning to form," Yeomans said. The relatively close approach to earth has given scientists an opportunity to determine its composition, he added.


Last week astronomers at the laboratory managed to photograph the comet from the Hubble Space Telescope, which travels in an orbit 560 kilometers above the earth.


While initial experiments have already detected several distinct molecules in the comet, a JPL spokesman said that definitive results were not yet available.


The biggest problem lies in the nucleus, the source of all material in the huge visible cloud around it. Since this nucleus has a diameter that is no more than 3 kilometers long, experiments designed to measure its chemical composition have been more difficult than scientists originally anticipated.


Nevertheless, scientists say the power jets shown streaming away from the glowing center in the photos show that Hyakutake has made several previous trips through the inner solar system. As Hyakutake is warmed by solar energy, natural geysers erupt with great force through holes in a crust on the comet's surface.


If a comet has made a number of trips around the sun, it develops an icy crust. On the comet's return toward the sun, material under the crust erupts and forms spectacular jets rather than the uniform outflow that would take place on first orbit.


While the origins of Hyakutake are unclear, astronomers believe it comes from the Oort Cloud, a swarm of more than 100 billion comets surrounding the solar system at a distance of as much as 150,000 times that between the sun and the earth. While the comets move very slowly in the cloud, a passing star may change their orbits enough to force some to the inner parts of the solar system.


A number of comets have been observed to fall apart as they moved closer to the sun, but unlike Hyakutake, most of these had nuclei that were only loosely held together. And despite some claims that Hyakutake may be disintegrating, pictures from the Hubble Space Telescope showed no indication that the nucleus was splitting.


"Normally, pieces break off a comet, and that's quite normal," Palmer said. "But if it did completely disintegrate that would be a great surprise."





In central Moscow, Hyakutake may appear to the naked eye as little more than a fuzzy star. It can be seen more clearly in the countryside or in the observatory of the Moscow City Palace of Creativity for Children and Youth at 17 Ulitsa Kosygina. Tel: 939-8967. Nearest metro: Universitet. The observatory is usually open all night when skies are clear while the comet is visible.