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 n