Narrator: This is Science Today. Planets discovered
outside our solar system were found to have an elliptical
orbit, rather than the circular orbit of our own planets.
Geoff Marcy, a professor of astronomy at the University
of California, Berkeley, says this makes astronomers
wonder if circular orbits are necessary for the evolution
of advanced life.
Marcy: If instead, the Earth were residing
in an elliptical orbit, then of course the Earth would
get carried close to the sun and far from the sun
and close to sun, alternately heating up the water
to steam and the other half of the time, freezing
the water on the Earth into ice. And of course, that
would not bode well for the quiescent evolution of
microbiology and life in general.
Narrator: Marcy says their results are a bit
scary for researchers looking for extra-terrestrial
Marcy: But I try to assure them they should
not be scared - only five percent of the stars we've
looked at have Jupiters. And although those Jupiters
are in elliptical motion, the other ninety-five percent
of our stars could very well have Earth-like planets
in circular motion.
Narrator: For Science Today, I'm Larissa Branin.