A team of astronomers announced they have discovered the
smallest and potentially most Earth-like extrasolar planet yet.
Five times as massive as Earth, it orbits a relatively cool star
at a distance that would provide earthly temperatures as well,
signaling the possibility of liquid water. “The separation
between the planet and its star is just right for having liquid
water at its surface,” says astronomer and team spokesperson
Stephane Udry of the Observatory of Geneva in Versoix,
Switzerland. “That’s why we are a bit excited.” But researchers
do not yet know if the planet contains water, if it is truly
rocky like Earth, which might make it hospitable to life as we
know it, or whether it is blanketed by a thick atmosphere. “What
we have,” Udry says, “is the minimum mass of the planet and its
separation” from its star. The researchers say they detected the
presence of two new extrasolar planets (exoplanets) around a red
dwarf star, Gliese 581, 20.5 light-years away in the
constellation Libra, based on slight