via Space.com, astronomers have announced that they have discovered the youngest extra solar planet yet orbiting a star very similar to our own. The planet, estimated to be only 10 million years old, orbits the star TW Hydrae 180 light years from Earth in the constellation Hydra at .4 AUs and is around ten times the mass of Jupiter.
"The extrasolar planet is an estimated 8 million to 10 million years old, a mere toddler compared to Earth, which is 4.5 billion years old. Until now, the researchers say, no planet younger than 100 million years old has been detected circling a sun-like star."
The most interesting item about the discovery is that the planet has formed before the protoplanetary dust disk has dissapated, the first a planet like this has been observed directly. Other systems have shown evidence of young planets by astronomers noting clear trails in the dust cloud surrounding these stars.