On Monday, researchers announced that they are one step closer to finding Earth’s twin. NASA’s Kepler mission has confirmed its first planet in the “habitable zone,” the region where liquid water could exist on a planet’s surface.
With the global population rushing past 7 billion earlier this year, space for human development on the Earth’s surface is becoming a valuable commodity. Just in case we can’t slow our exploitative behaviors in time to save this planet, scientists at NASA are already hard at work looking for a suitable substitute elsewhere in the universe.
The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our sun. The planet is about 2.4 times the radius of Earth. Scientists don’t yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but say that its discovery is encouraging.
“This is a major milestone on the road to finding Earth’s twin,” said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. “Kepler’s results continue to demonstrate the importance of NASA’s science missions, which aim to answer some of the biggest questions about our place in the universe.”
While it is the only Kepler discovery to be confirmed, 22b certainly isn’t the first planet that could possibly support human life in the future. In February the Kepler mission discovered dozens of planets in the habtiable zone.
“The tremendous growth in the number of Earth-size candidates tells us that we’re honing in on the planets Kepler was designed to detect: those that are not only Earth-size, but also are potentially habitable,” said Natalie Batalha, Kepler deputy science team lead at San Jose State University in California. “The more data we collect, the keener our eye for finding the smallest planets out at longer orbital periods.”
Since 22b is over 600 light-years away, it will be some time before we have the technology to transport the materials and people it would take to build a civilization there. In the mean time, we should probably find a way to keep from destroying the Earth we’ve got.
Image: Artist’s conception of Kepler-22b