| |
Comet and Asteroid Hunters'
Discovery Streak Continues
by John Fleck, 10-7-99, Journal Staff Writer
A team of New Mexico astronomers has discovered a comet that could be bright enough to be seen with the naked eye
next summer.
It's the latest in a string of significant finds for the LINEAR telescope outside Socorro. In recent weeks, it
has also:
* Found the fourth object ever discovered that has a chance -- extremely remote at this point -- of hitting Earth
* Rediscovered a "Trojan," a rare type of asteroid shepherded in a stable orbit by the planet Jupiter.
The asteroid was first seen in 1906, then lost to science until the LINEAR telescope picked it up in September.
In the two years since the LINEAR telescope began hunting for faint moving objects in the sky, it "has moved
our knowledge of the entire asteroid population forward by decades relative to the pace of discovery before they
came on line," said Steve Chesley, an astronomer at the University of Pisa in Italy.
LINEAR -- the Lincoln Near-Earth Asteroid Research -- uses an Air Force telescope at the north end of White Sands
Missile Range. It is run by Lincoln Laboratory at the Massachusetts Institute of Technology. LINEAR uses instruments
developed for satellite tracking to scan the sky each night, looking for objects that move. Using an automated
system and a highly sensitive electronic camera, the LINEAR team has revolutionized the hunt for asteroids and
comets.
And the pace of discovery is likely to increase, with a second telescope at the site beginning operation this month.
The latest comet discovery is one of a series that has established LINEAR as the dominant comet-hunting team in
the world.
Of the 14 comets currently visible through telescopes, seven were discovered by LINEAR. A comet's performance is
notoriously difficult to predict, but the one found last month by LINEAR could be bright enough to be of scientific
importance, said Brian Marsden, who tracks comets for the International Astronomical Union.
The newly discovered comet isn't going to be a dramatic sight like Comet Hyakutake in 1996 or Hale-Bopp in 1997,
but it could be bright enough to be easily seen with binoculars, or possibly with the naked eye, Marsden said.
"We're doing pretty well on comets these days," said Grant Stokes, director of the LINEAR program. Chesley
is interested in asteroids that have the potential to collide with Earth. On Tuesday he circulated electronic mail
asking telescope users around the world to begin tracking an asteroid discovered by LINEAR last month.
Based on preliminary data, the object has a tiny chance of hitting Earth in 2042 or 2050, Chesley calculated. The
risk is so small that it "is not of serious concern to the public at large," Chesley said.
More observations are needed to pin the orbit down more precisely, Chesley said in an e-mail interview Tuesday.
The oddest discovery is the Trojan asteroid spotted in September.
Studying old data, Gareth Williams of the International Astronomical Union realized the object had been seen in
1904 by Edward Emerson Barnard with what was at the time the largest telescope in the world, at Yerkes Observatory
in Wisconsin.
|
|
