Worlds that could hold life and water in the 'Goldilocks zone'

This may be off topic for an electrician, but we found it really exciting.

Eight more planets have been discovered that could possess watery oceans and life, including two of the most Earth-like yet found.

The new worlds double the number of small exo-planets believed to be circling their stars in the “habitable zone” - the narrow region in which temperatures are mild enough to allow liquid surface water.

“Most of these planets have a good chance of being rocky, like Earth,” said lead scientist Dr Guillermo Torres, from the Harvard-Smithsonian Centre for Astrophysics in Cambridge, US.

The two most Earth-like planets, known as Kepler-438b and Kepler-442b, both orbit red dwarf stars that are smaller and cooler than the Sun.

With a diameter just 12 per cent bigger than Earth, Kepler-438b has a 70 per cent chance of being rocky, the scientists have calculated. Kepler-442b is about one-third larger than Earth, and the likelihood of it being rocky is around 60 per cent.

An artist's impression of Kepler-186f which may have conditions suitable to life An artist's impression of Kepler-186f which may have conditions suitable to life  To be in the habitable zone, also known as the “Goldilocks zone”, a planet must be not too hot or too cold and receive roughly as much sunlight as Earth.

Too much heat from its star, and any water would boil away as steam. Too little, and the water would freeze solid.

“For our calculations we chose to adopt the broadest possible limits that can plausibly lead to suitable conditions for life,” Dr Torres added.

Kepler-438b receives about 40 per cent more light than the Earth giving it a 70 per cent probability of having a habitable zone orbit. In comparison, baking hot Venus has twice as much.

The other star gets about two-thirds as much light as Earth and is 97 per cent likely to be in the habitable zone.

An artist's impression of Kepler-16b, a world where two suns set over the horizon instead of just one, the planet is the most  An artist's impression of Kepler-16b, a world where two suns set over the horizon instead of just one, the planet is the most "Tatooine-like" planet yet found in our galaxy  Co-author Dr David Kipping, also from the Centre for Astrophysics, said: “We don't know for sure whether any of the planets in our sample are truly habitable. All we can say is that they're promising candidates.”

Neither of the planets are our close neighbours. Kepler-438b is located 470 light-years from Earth while the more distant Kepler-442b is 1,100 light-years away.
The team, whose findings were presented at the American Astronomical Society's annual meeting in Washington DC, studied planetary candidates first identified by the US space agency Nasa's Kepler space telescope.

found on the independent web site

“small” astronomers mean planets with less than twice the Earth's diameter.