NASA on Monday announced it had discovered what could be the most Earth-like exoplanet yet — and the one with the best potential of supporting life besides Earth — using its Kepler orbital spacecraft and the Spitzer Space Telescope.
“This is a major milestone on the road to finding Earth’s twin,” said Douglas Hudgins, Kepler program scientist, in a press release from NASA’s Jet Propulsion Laboratory.
The newly discovered planet, Kepler-22b, is 2.4 times the radius of Earth and is locked in a 290-day orbit, similar in length to that of Earth’s year, around a star similar to our Sun located 600 light years away.
Most importantly, Kepler-22b is located within the so-called “Goldilocks Zone,” aka the “habitable zone,” the distance from a star at which a planet can support liquid water on its surface (i.e. where the “porridge” is neither too hot nor too cold).
The surface temperature on the planet is estimated to be a balmy 70 degrees Fahrenheit, Science magazine reported.
Still, scientists can’t say for certain yet whether there is any liquid water on the planet’s surface, as its mass, and thus composition, have yet to be determined.
NASA announced the finding at the start of a five-day science conference at the Ames Research Center in Moffett Field, CA.
But the discovery of Kepler-22b might prove to be just the type of the extraterrestrial iceberg, as NASA also announced that the Kepler mission had discovered no fewer than 1,094 new planet candidates, 89 percent more than the agency reported in February.
That brings the total number of exoplanets up to 2,326, although NASA did lower the total number of potentially habitable ones from 54 to 48 based on a new, refined and stricter definition of the “Goldilocks Zone,” which takes into account the fact that atmospheric conditions can warm a planet.
NASA’s Kepler spacecraft was launched in 2009 specifically to search our galaxy, the Milky Way, for Earth-like worlds. The spacecraft surveys the sky using a photometer, a light-detecting telescope that is sensitive enough to detect the shadow of an Earth like planet moving in front of a star in what amounts to an eclipse from our (the instrument’s) point of view. It is from these shadows that Kepler scientists are able to pinpoint the existence of exoplanets.
We’ve reached out to NASA for more information on this discovery and what else the Kepler science conference promises, and we’ll update when we receive a response.