Subj: | Astronomers Find Life Ingredients |
Date: | 2/20/01 7:54:28 AM Pacific Standard Time |
From:
hblondel@tampabay.rr.com To: hblondel@tampabay.rr.com (Newmill) |
FEBRUARY 20, 06:02 EST
Astronomers Find Life Ingredients
SAN FRANCISCO (AP) Complex carbon molecules and water, which are
key
ingredients for life, have been found in the dust and gas around
distant
stars. The findings boost the theory that the cosmic stew of life is
common in the universe.
Astronomers reported Monday that orbiting observatories probing the
space around both young and dying stars have found vast waves of water
vapor and clear traces of carbon molecules that can play a basic role
in
organic chemistry.
"This strengthens greatly the possibility of life forming elsewhere,"
said Martin F. Kessler, a staff scientist for the European Space Agency.
"It shows that complex carbon chemistry is not unique to Earth. We now
see similar chemistry elsewhere in the universe."
The findings don't prove that life exists beyond the Earth, said
Martin
Harwit, a Cornell University astronomer. "But it proves that the
conditions that led to the formation of life and our solar system
are
present in lots of places."
Harwit was chairman of a panel of researchers who presented data on
Monday from the Submillimeter Wave Astronomy Satellite and the
Infrared
Space Observatory. The panel appeared at the national meeting of
the
American Association for the Advancement of Science.
Gary J. Melnick, leader of an international team that built the
astronomy satellite, said in a statement that water vapor is common
and
plentiful in warm regions around forming stars.
Inside gas clouds where new stars are forming, temperatures soar to
several thousand degrees, setting off chemical reactions favoring
production of water, said Melnick, a scientist at the
Harvard-Smithsonian Center for Astrophysics.
This chemical churning, he said, results "in water being one of the
most
abundant molecules in these clouds."
In chilled parts of the star-forming clouds, water vapor is rarely
detected, however.
Edwin Bergin of the Harvard-Smithsonian center suggests that the water
is there, but in the form of ice that is coating dust grains.
Bergin suggested that these ice-covered grains could collide, stick
together and form increasingly larger objects, eventually becoming
the
"building blocks of planets" in a new solar system.
"The water released when these planets form may collect into oceans
and
lakes," Bergin said. "Those bodies not incorporated into planets may
become what we call comets."
Bergin said the finding is evidence that water is plentiful in
interstellar space and "could perhaps have been delivered to
other
proto-earths out there. If it could happen to Earth, then it could
possibly happen to other planets as well."
"The fact that water is found in regions that give rise to the formation
of stars is a good sign that the conditions for life are there,"
said
Harwit.
Kessler said the Infrared Space Observatory has made the first deep
space discovery of benzene, a ring-shaped molecule with carbon atoms.
This finding is significant, said Kessler, because small molecules
like
benzene "could join together to form the big, complex carbon molecules"
that have been found in earlier studies.
He said benzene could be a "missing link" between simple molecules with
no more than eight carbon atoms and the more complex molecules,
with
hundreds of carbon atoms, that are found in living organisms.
"This advances the idea that complex organic chemistry necessary for
life could take place in the stellar medium," said Kessler.
A major goal of astronomers studying the brew of life in outer space is
to look for amino acids, the building blocks of protein, said Harwit.
Amino acids have been found in some types of meteorites, space rocks
that have fallen to Earth, but they have not been detected in outer
space.
"Some of the larger molecules that we have found are getting close to
amino acids," said Harwit. "The chances are that amino acids may be rare
and we will need increasingly sensitive instruments to find
them."