From: | NewsProfiles@aol.net |
Title: | COMET HYAKUTAKE MAY OFFER CLUES TO SOLAR SYSTEM'S ORIGINS |
Source: | Reuter |
Date: | March 23, 1996 |
SOCORRO, New Mexico, March 23 (Reuter) - Astronomers and
amateur stargazers are keeping watch worldwide this weekend for
Comet Hyakutake, which is due to pass unusually close to Earth
on Sunday and may offer clues about the origins of the solar
system.
Not far from where the first atomic bomb was tested half a
century ago, scientists in Socorro are using a new generation of
radio telescope technology to gain what they hope will be
Earth's most detailed look at a comet ever.
``This is a unique kind of opportunity that the global
astronomical community has to try to get a little bit of
information about a world that in many ways is a Rosetta Stone
for answering fundamental questions about our origins and the
universe we live in,'' said Steve Ostro, a senior research
scientist at NASA's Jet Propulsion Laboratory in Pasedena,
California.
Comets -- ``dirty snowballs'' of rock and ice usually a mile
or less to six miles (one to 10 km) long -- may provide clues on
the universe's origins. They have changed very little since the
solar system's birth 4.5 billion years ago, whereas planets,
stars and other larger bodies have constantly evolved.
Thus comets such as Hyakutake could contain some of the very
building blocks of life, ``and provide part of the information
we need to conjecture about the likelihood that there are other
solar systems like ours ... or other intelligent life in the
universe,'' Ostro said.
``They're probably a lot closer to the material the solar
system formed from than anything else we have ever gotten access
to or are likely to get access to,'' he added.
Hyakutake -- officially Comet C/1996 B2 -- was discovered in
late January and quickly excited astronomers because of its
close rendezvous with Earth.
It will be the fifth closest comet to pass by this century
and the comet's radio emissions may enable scientists to detect
some of the chemicals that make up its core.
``Its emission activity plus its close approach to Earth
make it incredibly interesting,'' said Lewis Snyder, a professor
of astronomy at the University of Illinois who is using radio
telescopes to determine Hyakutake's composition.
Many of the comet observations will take place at the Very
Large Array (VLA), a unique complex of 27 closely positioned
radio telescopes managed from Socorro about 50 miles (80 km) to
the east.
In the countdown to the start of experiments here on Sunday,
experts were still reworking calculations to ensure instruments
are pointed to the core comet, which is typically hidden behind
a gaseous atmosphere that can extend up to a million miles as it
approaches the heat of the sun.
``The problem is that the comet is so diffuse, we may not be
hitting the right point,'' said Pat Palmer, a University of
Chicago astrophysicist helping calculate where to point the VLA
telescopes.
The proximity of Hyakutake 9.3 million miles (15 million km)
away on Sunday also helps astronomers to solve other riddles
such as why a comet appears to travel surrounded by pebbles and
rocks.
Berkeley astronomy professor Imke de Pater hopes to answer
the question by bouncing microwave signals from California to
the speeding comet and back to the VLA 100 seconds later, a
process that may offer a detailed view of Hyakutake and its
surrounding objects.
Astronomers hope to gain a wealth of data from Hyakutake,
but they say earth-based observations pale with the possibility
of sending a spacecraft to mine samples directly from a comet, a
project under consideration by the European Space Agency.
``It would be like being able to step back into a time
machine,'' Ostro said.
Added John Harmon, assistant director of the Arecibo
Observatory in Arecibo, Puerto Rico: ``It's definitely feasible
and if you really want to understand what the surface is like,
you really need to send a spacecraft there and take a look at
it.''