* Astronomy

First Earth-sized planets spotted

Astronomers have detected the first Earth-sized planets, which are orbiting a star similar to our own Sun.
In the distant past they may have been able to support life and one of them may have had conditions similar to our own planet - a so-called Earth-twin - according to the research team.
One of the planets, named Kepler 20f, is almost exactly the size of the Earth. Kepler 20e is slightly smaller at 0.87 times the radius of Earth and is closer to its star than 20f.
They are both much closer to their star than the Earth is to the Sun and so they complete an orbit much more quickly: 20e circles its star in just six days, 20f completes an orbit in 20 days whereas the Earth takes a year.
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