Two Planets Identified As Most Similar To Earth
After locating more than 340 planets orbiting other stars, astronomers have identified two that are the most similar to Earth so far.
The most recently discovered one is almost twice as large as Earth, making it the smallest exoplanet — for extra-solar planet — found to date. The second one was found in 2007, but new observations have shown that it is the only exoplanet to date that orbits its star in the so-called habitable zone, where water remains a liquid. Thus, it is the only exoplanet discovered that is likely to have oceans.
Intriguingly, both orbit the same star, a dwarf 20 light-years from Earth called Gliese 581, European researchers said Tuesday.
The identification of the small planet “is a remarkable discovery and bodes well for our eventual discovery of a true Earth-like, habitable planet,” astronomer Alan Boss of the Carnegie Institution of Washington wrote in an e-mail.
