Space, The Final Frontier...

Planets Found in Potentially Habitable Setup

Three medium-sized planets of roughly the same mass as Neptune have been discovered around a nearby Sun-like star, scientists announced today.

The planets were discovered around HD 69830, a star slightly less massive than the Sun located 41 light-years away in the constellation Puppis (the Stern), using the ultra-precise HARPS spectrograph on the European Southern Observatory's 3.6-meter La Silla telescope in Chile.

The finding, detailed in the May 18 issue of the journal Nature, marks a first for astronomers because previously discovered multi-planet solar systems besides our own contain at least one giant, Jupiter-sized planet.

"For the first time, we have discovered a planetary system composed of several Neptune-mass planets," said study team member Christophe Lovis of the Geneva Observatory in Switzerland.

The setup is similar to our own solar system in many ways: The outermost planets is located just within the star's habitable zone, where temperatures are moderate enough for liquid water to form, and the system also contains an asteroid belt.

The newly discovered planets have masses of about 10, 12 and 18 times that of Earth and they zip around the star in rapid orbits of about 9, 32 and 197 days, respectively.

Based on their distances from the star, two inner worlds nearest the star are rocky planets similar to Mercury, the scientists suspect. The outermost planet is thought to have a solid core of rock and ice and shrouded by a thick gas envelope.

Recent observations by NASA's Spitzer Space Telescope last year revealed that HD 69830 also hosts an asteroid belt, making it the only other Sun-like star known to have one.

Check out the article at Space.com.

I wonder how long it will be before we have the technology to make the trip and colonize those planets, and others like them. Our planet really is a sitting duck for some random space collision. At least we could lessen the odds of having our entire civilization wiped out with one collision.