From: UFO UpDates - Toronto <ufoupdates.nul>
Date: Wed, 08 Sep 2004 16:26:22 -0400
Fwd Date: Wed, 08 Sep 2004 16:26:22 -0400
Subject: The Search For Livable Worlds




Source: The New York Times

Editorials/Op-ed

http://www.nytimes.com/2004/09/08/opinion/08wed3.html?ex=1095307200&en=4dc436d89ed1d709&ei=5006&partner=ALTAVISTA1

09-08-04


The Search For Livable Worlds

Published:

Scientists eager to find life on other worlds - or at least ones
that might support Life as We Know It - felt a shiver of
excitement last week. Three teams of astronomers reported
finding the smallest distant planets yet detected, suggesting
that Earth-size planets with benign climates might be just
around the corner. But there was a bit of discouraging news as
well. A new calculation suggests that scientists may be looking
in the wrong places for messages sent by any distant intelligent
beings.

The pace of planetary discovery has been steadily quickening. A
decade ago scientists did not know of even a single planet
outside our solar system. Now they have found more than 100. Of
course, they haven't actually seen them. They are far too
distant and dim. Instead, scientists have inferred their
presence from the slight wobbles their gravitational pull causes
in their stars or from a slight dimming of a star's light as a
planet passes across it.

Until last week, all the planets detected had been huge, gaseous
blobs circling their suns at very close range. That is no
surprise. The bigger and closer a planet is, the more likely it
is to cause its star to wobble. But two American teams and one
European team have now detected planets the size of Neptune or
Uranus, some 14 to 20 times the mass of Earth. These planets,
too, orbit their stars at too close a range for our form of
life. But scientists say they are increasingly comfortable with
the notion that there are an enormous array of planets out
there, and that some of them are bound to be rocky orbs with
temperatures that can permit liquid water and possibly life.
Probably no Earth-size planet will be found until NASA launches
a planet-hunting spacecraft in coming years.

Meanwhile, scientists searching for extraterrestrial
intelligence will still scan electromagnetic waves reaching
Earth for signs of a message that a far-off civilization may
have sent.

The theory has been that radio waves or lightwaves are the
fastest way to send messages across interstellar distances, so
they are the most likely form of communication for an
intelligent civilization. But an analysis in Nature this week
suggests that a message longer than just a "Hi, we're here" kind
of thing would be sent most efficiently in physical form, much
like a message in a bottle. That suggests that we should be
looking for the alien equivalent of a letter in our own
planetary backyard, analogous to the monolith left on the moon
by aliens in "2001: A Space Odyssey" by Arthur C. Clarke. The
only hitch is that such a message, traveling at a crawl by space
standards, might have been sent 30 million years ago, and who
knows whether the senders would have moved on or died off in the
eons since. Best not to give up on electromagnetic messages
entirely.


[UFO UpDates thanks Greg Boone for the lead]