THIS DIAMOND PLANET WILL LAST FOREVER

Astronomers have found the remains of a once-massive star, now transformed into a solid diamond five times bigger than Earth.

The object circles a pulsing companion star about 4,000 light years from Earth in the constellation Serpens (The Snake), which lies about one-eighth of the way toward the center of the Milky Way galaxy.

Astronomers noticed that the steady pulses of energy coming from the star, known as J1719-1438, were regularly and minutely disturbed, a phenomenon caused by the gravitational tug of another, smaller circling object.

NEWS: Planet in the Sky With Diamonds

By measuring the pattern, scientists were able to figure out how far away the second object circles and its mass, leading to the realization that they had found a bizarre binary system, with one partner reduced to a diamond core.

CAN ELECTRIC CARS WIN OVER THE MASS MARKET?

It's not every day that a U.S. governor accepts an invitation to the launch of a Japanese-built car, but Nissan's all-electric Leaf offers environmental credentials that top any nationalistic concerns.

"Illinois is laying the groundwork for electric vehicles and a more green economy, and our efforts are paying off," Governor Pat Quinn said Thursday, as he thanked Nissan for bringing the Leaf to his state months earlier than originally planned.

"By investing in electric vehicle technology, both the state of Illinois and Nissan are making transportation in our state more efficient, sustainable and affordable."

The first mass-market electric vehicle has won some high-profile fans since it was launched in Japan and a handful of U.S. markets in December, and in Europe earlier this year.

NEWS: Electric Car Can Power Home

The Leaf emits none of the tailpipe pollutants that have covered city skies in smog and is touted as a step forward from gas-electric hybrids produced by the likes of Toyota, which makes the best-selling Prius.