118 lines
6.5 KiB
Plaintext
118 lines
6.5 KiB
Plaintext
**********************************************************************
|
|
|
|
*NASA URGED TO SEEK OUT INTELLIGENT LIFE*
|
|
|
|
Space scientists in America have a new dream - to discover another
|
|
planet like Earth, writes Robin McKie.
|
|
|
|
American scientists are planning to go fishing - for planets. A
|
|
growing research lobby believes the United States should channel it's
|
|
space resources towards detecting other solar systems that might
|
|
support life. The move would shift funding away from expensive manned
|
|
expeditions, for instance to Mars, and would instead exploit
|
|
recently established technologies for building oriting observatories,
|
|
such as the Hubble space telescope.
|
|
|
|
Robert Brown of the Space Telescope Science Institute in Baltimore
|
|
says: "Such a hunt would strike a chord with the public. The
|
|
National Aeronautics and Space Administration (NASA) is trying to
|
|
find a purpose for it's existance. It could do no better than this.
|
|
It would be popular and make a real contribution to history.
|
|
|
|
Dr Brown, speaking last week at the American Association for the
|
|
Advancement of Science, is a noted enthusiast for planet-hunting. But
|
|
he is not alone. Several other speakers stressed that they now
|
|
believe solar-system spotting has matured sufficiently to begin
|
|
realistic hunts. Nasa is currently seeking a new rationale. It's
|
|
orbiting space-station, Freedom, only just survived a series of
|
|
congressional budget cuts and the agency's traditional approach of
|
|
planning ever more ambitious manned missions, to culminate in a $50
|
|
billion (u31 billion) landing on Mars early next century looks
|
|
increasingly vulnerable. Critics argue that the two-year mission
|
|
would only prove what we already know - that Mars is red, dead, and
|
|
boring. The popular alternative within the space community would be
|
|
to commit NASA to a search for other worlds, a task which has
|
|
previously stumped astronomers because stars emit a billion times
|
|
more light than even the largest planets, like Jupiter. Observer's
|
|
ability to see smaller, warmer worlds (where life has it's best
|
|
prospects) against the glare of the stars has therefore proved to be
|
|
limited. Nevertheless, the first planets have been hooked. At
|
|
Pennsylvania State University, Dr. Aleksander Wolszczan has detected
|
|
three - in orbit around a star called PSR 1257+12. The star is a
|
|
pulsar, an old, extremely dense object, 12 miles in diameter, which
|
|
revolves at an astonishing 160 times per second. From
|
|
perturberations in the regular pulses emmitted by this "astronomical
|
|
lighthouse", Dr. Wolszczan detected two planets slightly bigger han
|
|
Earth and one much smaller, about the size of Mercury. His discovery
|
|
suggests planets may be ubiquitous, for if they can survive near
|
|
pulsars, created when starts first explode as supernovae and then
|
|
condense in on themselves, they should exist everywhere. The
|
|
cataclysmic creation of PSR 1257+12 should have destroyed any planets
|
|
in it's vicinity. So how did they get there? Researchers speculate
|
|
that PSR 1257+12 may have had a companion star from which the pulsar
|
|
slowly drew off gas and dust until it's partner was destroyed. From
|
|
the debris planets evolved. Life there must be slightly odd, however.
|
|
"You would have to protect yourself against a giant pulsing x-ray
|
|
machine," Dr. Wolszczan said. "You would have to carry a lead
|
|
umbrella all the time." Not surprisingly, scientists look to other,
|
|
far more "normal" stars for signs of planets that might support life.
|
|
"There are about 1,000 stars like our Sun within 100 light years of
|
|
Earth, so there should be no shortage of fish in our pond," said
|
|
David Latham of the Harvard-Smithsonian Centre for astrophysics. "For
|
|
example, Tau Ceti, near the constellation Pisces, is only 11.7 light
|
|
years distant and is extraordinarily like our Sun. It must be a very
|
|
good prospect." And if there are plenty of promising stars, ans
|
|
evidence that planets are ubiquitous, our extra-terrestial search
|
|
should have considerable promise. Unfortunatly, other conference
|
|
speakers provided evidence that undermined this optimism. Research
|
|
by Andrea Ghez of the university of California, Los Angeles, has
|
|
found that three-quarters of young stars are born with one or more
|
|
companion stars. "That is bad news for planets' prospects," she
|
|
said. "Planets form out of disks of dusk that slowly accrete into
|
|
larger and larger bodies. A companion star would sweep through these
|
|
disks, depleting the dust and rocks. There would not be enough left
|
|
for planets. Solar systems may be the the exception, not the rule,
|
|
in our galaxy."
|
|
|
|
Scientists are faced, therefore, with contradictory evidence about
|
|
the ubiquity of other worlds. But now they posses the means to
|
|
begin to find out who is right. "We have finally built a telescope
|
|
outside our atmosphere which will detect other planets," Dr. Brown
|
|
said. "We will soon finish the Copernican Revolution. We have shown
|
|
planets go around the Sun, but may soon be able to show they go round
|
|
other stars as well." Dr. Brown said advanced cameras were due to be
|
|
flown to the space telescope in 2002. These would exploit methods,
|
|
known as Fourier techniques, which would suppress the glare of o star
|
|
and reveal it's planets, if any. Once these new worlds had been
|
|
detected, a new space telescope, on the Moon or in deep space -
|
|
could be built to study such planets' atmospheres for the presence of
|
|
chemicals produced by living beings. Such a telecscope would
|
|
probably exploit the principles of interferometry, in which two
|
|
seperate instruments combine to produce extremely powerful
|
|
observations.
|
|
If it sounds like a dream, consider the words of the
|
|
NASA director Daniel Goldin: "What if we were to build an
|
|
interferometer on the moon? And what if it were big enough that we
|
|
could not only image planets around distant stars, but do
|
|
spectroscopic analyses of their atmospheres? Results might "change
|
|
our society in matters we can't even comprehend". Humanity would
|
|
either learn that life is rare, and therefore precious, or that
|
|
humans are just an "ever so 'umble" species in an alien-filled
|
|
universe. "We should get the answer soon," Dr. Brown said. "We have
|
|
put out hooks. Soon we will be draining the lake.."
|
|
|
|
**********************************************************************
|
|
|
|
|
|
|
|
"change our society in matters we can't even comprehend"
|
|
|
|
Hmmm.. sounds as if "they" are preparing to "find" some aliens.. :)
|
|
|
|
|
|
|
|
:::%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%:::
|
|
:::%%%ET-=-MAILSYSTEM. "ET" <be1ewt@rgueee.rgu.ac.uk>:::
|
|
:::%%%%%%%%%%%%%%%%%%%%%%%AMIGA%%%%%%%%%%%%%%%%%%%%%%%:::
|
|
|