Real science: Exoplanets in Gliese 581 system - one twice earth mass, another in habitable zone

Science Daily: Newly discovered "Gliese 581 e", fifth world to be found in "Gliese 581" solar system about 20 light years from Sol, is just 1.9 times earth mass - but too close to its sun to be inhabitable.

But a previously known world in this system, "Gliese 581 d", is now thought to be "well within the habitable zone", though it is 7 times as massive as earth. It "could even be covered by a large and deep ocean — it is the first serious 'water world' candidate".

[via 42Blips]