Astronomers predict that the first confirmed Earth-like planet will be found next year.
More than 800 Earth-sized planets have been discovered orbiting stars since the first was found in 1995.
Fewer have been identified as having ideal temperatures, sitting inside the “Goldilocks Zone”, an orbital sweet spot – not too cold, not too hot – which allows water to exist in its liquid state. However, this alone does not mean they are inhabitable.
Only nine planets have been flagged as having the potential to sustain life.
But none have yet been officially declared “Earth-like” – either because of their excessive size, high speed or simply a lack of available information.
The vast bulk of discoveries so far have been Jupiter-like gas giants.
“I’m very positive that the first Earth twin will be discovered next year,” Astronomer Abel Mendez, from the Planetary Habitability Lab at the University of Puerto Rico, told Mashable today.
He and other astronomers say new instrumentation, such as the Kepler telescope, using advanced observational techniques are making it easier to detect small planets at greater distances – as well as get greater information on planets at smaller distances.
Such equipment is now available with NASA’s Kepler Space Telescope and the European Southern Observatory’s HARPS telescope in Chile.
An Earth-like planet, Kepler 22-B, has been discovered and it could be right for life.
Possibly the best candidate so far, Kepler 22-B is a “Goldilocks” planet, some 2.4 times bigger than Earth and was found by the Kepler Space Telescope in December last year. However it’s most obvious problem is the 600 light year distance to this planet.
“The first planet with a measured size, orbit and incident stellar flux that is suitable for life is likely to be announced in 2013,” Kepler team member Geoff Marcy said.
Two other planets recently found orbiting two of our closest neighbours, Tau Ceti and Alpha Centauri, are likely to also receive careful attention due to their closer proximity.
One of the most promising and nearby planets is Gliese 581g. This rocky world, if it does indeed exist, is just 20 light-years away from our solar system. It’s likely two to three times as massive as Earth and zips around its parent star, the red dwarf , every 30 days or so.
Based on current data, astronomers have estimated that there are some 200 billion stars in our galaxy, with at least 50 billion planets orbiting them.
They estimate that roughly 1 in 10,000 are similar to Earth. This could give us five million Earth’s in our galaxy alone.
A selection of artists concepts of recently discovered planets.