Scratch these off:

- Places to visit
- Places to colonize

Oh well......

---------------------------------------------------
http://www.eurekalert.org/pub releases/2004-07/ppa-tcs063004.php


UK astronomers studying the Tau Ceti system have discovered that it
contains ten times as much material in the form of asteroids and comets
as our own solar system. Their discovery, being published in Monthly
Notices of the Royal Astronomical Society, suggests that even though Tau
Ceti is the nearest Sun-like star, any planets that may orbit it would
not support life as we know it due to the inevitable large number of
devastating collisions. It also suggests that the tranquil space
environment around the Earth may be more unusual than previously
realised.

SNIP
UK participation in the James Clerk Maxwell Telescope is provided by the
Particle Physics and Astronomy Research Council (PPARC). Professor Ian
Halliday, PPARC Chief Executive said "SCUBA continues to unveil the
mysteries of planetary systems, in this case the
"asteroid alley" that is Tau Ceti; - clearly a place you would not wish
to be."

Scratch these off:

- Places to visit
- Places to colonize

Oh well......

---------------------------------------------------
http://www.eurekalert.org/pub_releases/2004-07/ppa-tcs063004.php


UK astronomers studying the Tau Ceti system have discovered that it
contains ten times as much material in the form of asteroids and comets
as our own solar system. Their discovery, being published in Monthly
Notices of the Royal Astronomical Society, suggests that even though Tau
Ceti is the nearest Sun-like star, any planets that may orbit it would
not support life as we know it due to the inevitable large number of
devastating collisions. It also suggests that the tranquil space
environment around the Earth may be more unusual than previously
realised.

Tau Ceti, only 12 light years away, is the nearest Sun-like star and is
easily visible without a telescope. It is the first star to be found to
have a disk of dust and comets around it similar in size and shape to
the disk of comets and asteroids that orbits the Sun. But the similarity
ends there explains Jane Greaves, Royal Astronomical Society Norman
Lockyer Fellow and lead scientist: "Tau Ceti has more than ten times the
number of comets and asteroids that there are in our Solar System. We
don't yet know whether there are any planets orbiting Tau Ceti, but if
there are, it is likely that they will experience constant bombardment
from asteroids of the kind that is believed to have wiped out the
dinosaurs. It is likely that with so many large impacts life would not
have the opportunity to evolve."

The discovery means that scientists are going to have to rethink where
they look for civilisations outside our Solar System.

Jane Greaves continues "We will have to look for stars which are even
more like the Sun, in other words, ones which have only a small number
of comets and asteroids. It may be that hostile systems like Tau Ceti
are just as common as suitable ones like the Sun."

The reason for the larger number of comets orbiting Tau Ceti is not
fully understood, explains Mark Wyatt, another member of the team: "It
could be that our Sun passed relatively close to another star at some
point in its history and that the close encounter stripped most of the
comets and asteroids from around the Sun."

The new results are based on observations taken with the world's most
sensitive submillimetre camera, SCUBA.

The camera, built by the Royal Observatory, Edinburgh, is operated on
the James Clerk Maxwell Telescope in Hawaii. The SCUBA image shows a
disk of very cold dust (-210 ºC) in orbit around the star. The dust is
produced by collisions between larger comets and asteroids that break
them down into smaller and smaller pieces.

UK participation in the James Clerk Maxwell Telescope is provided by the
Particle Physics and Astronomy Research Council (PPARC). Professor Ian
Halliday, PPARC Chief Executive said "SCUBA continues to unveil the
mysteries of planetary systems, in this case the
"asteroid alley" that is Tau Ceti; - clearly a place you would not wish
to be."