"Nick Mason" wrote in message
...
I was listening to Radio 4 earlier this evening and they were talking
about NASA and their Kepler mission and locating planets around distant
stars using the transit method where the light diminishes due to the
passage of a planet in front of the star.

I didn't hear all the program but it set me thinking, doesn't this
depend on us, Earth, and the distant planet being in the same plane so
that we see the transit? If the distant planet were orbiting so that
from Earth we never saw it transit the star we wouldn't know it existed,
would we?

Am I missing something here?

Isn't it statistically more likely that any such planet would orbit in a
way that we wouldn't see it rather than be aligned correctly so that we
can?
--

True, but because you can monitor so many stars simultaneously in a wide
field, you should find a few, even if you miss most of them. AFAIK the earth
based surveys have only found one planet using the transit method so far
(TrES-1) but there are also surveys checking stars with known planets,
looking for transits. See www.transitsearch.com for info on a Pro-Am survey.

Robin
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Robin Leadbeater
54.75N 3.24W
http://www.leadbeaterhome.fsnet.co.uk/astro.htm
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