Introduction
There is good news and bad news in the quest
for extrasolar planets as possible sites for the rise of intelligent life. The good news is that astronomers are beginning
to find convincing evidence for planets in orbit around stars like the
sun. The bad news is that none of the
planets discovered so far is anything like the earth. Instead, they are all giants, at least 100 times more massive
than the earth, and unlikely to be suitable for life as we know it.
The first good evidence for a system
of planets orbiting a solar-type star was announced April 15, 1999, by a team
of astronomers from four research institutions. The three planets in this system are also
giants. But, if they are like the giant
planets in our own solar system, they will have rocky moons, and one of those
moons just might prove to be inhabited (but I would not bet on it). More importantly, now that we have more than
just one example of a planetary system,
it is easier to imagine that somewhere there may be other systems with
earth-like planets orbiting in a habitable zone.
Contributed by: Dr. David Latham
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