This is Science Today. Our sun contains nine planets
and scientists have long wondered whether or not other
stars in the night sky might also harbor planets similar
to our own. Geoff Marcy, a professor of astronomy
at the University of California, Berkeley, says there's
been an ongoing search for many years now to find
Marcy: You can't actually see directly the
planet orbiting another star - the glare from the
star is just too bright to see the little tiny dot
of light that would be the planet. So instead, what
we do is we watch the stars to see if they move in
space - wobble around and around.
Narrator: That would indicate a gravitational
tug from the orbiting planet. But Marcy recently witnessed
one of these planets cross in front of its star, causing
it to dim.
Marcy: We've always known that there was a
chance that if you're lucky, the orbital plane of
the motion of the planet would take the planet right
in front of the star - just by luck. And so the transit
of the planet actually happened just as we had imaged
and always hoped.
Narrator: For Science Today, I'm Larissa Branin.