Scientists: There are one hundred million small, Earth-like planets in the Milky Way alone
Image via NASA
A co-investigarore on the Kepler satellite insitute surprised NASA this month with a major, unplanned announcement on data from the Kepler satellite. Eight minutes in to a speech at the TED global conference in Oxford, Sassanov announced that researchers believe the galaxy likely holds about 100 million “small, Earth-like planets,” and have actually identified over 100 of those planets.
Of course, “small, Earth-like” planet doesn’t mean the same thing as “small, life-supporting” planet. Sasselov’s speech created a fair bit of confusion, and numerous articles implied that the Kepler scientists had already found found 100s of “earths.” The confusion likely arose because the reporters did not listen to the entire speech, or even very much past the initial announcement. Sasselov made quite clear that the 100 or so planets the team had already identified, and the 100 million or so it estimated existed in the galaxy, need further study. Thankfully, Space.com was there to correct the sloppy journalism:
With further observation, half of them could well turn out to be false alarms. Many could also be Earth-like in size but orbiting so close to their stars that nothing but their size would be Earth-like. Sasselov said that astronomers will be able to identify at least 60 Earth-like planets. So the unauthorized presentation of preliminary results would seem to confirm that Kepler has succeeded in showing that Earth is no fluke.
Still, it’s an exciting announcement. One hundred million is a damn big number, and there’s a good chance a large number of them could support life. In fact, Sasselov, the director of Harvard’s Origins of Life Initiative, isn’t just looking for Earth-like planets. He and his team are also looking at how life begins (I guess the initiative’s name could tip you off). “Science is in the process of redefining life as we know it,” Sasselov says.
“And in one of our labs, Jack Szostak’s labs, it was a series of experiments in the last four years that showed that the environments–which are very common on planets, on certain types of planets like the Earth–where you have some liquid water and some clays, you actually end up with naturally available molecules which spontaneously form bubbles. But those bubbles have membranes very similar to the membrane of every cell of every living thing on Earth. . . . And they really help molecules, like nucleic acids, like RNA and DNA, stay inside, develop, change, divide and do some of the processes that we call life.”
“There is immense potential for life in this universe,” he added later, “especially now that we know that places like the earth are common. And that potential, that powerful potential is also ours, of you and me.”
Watch the full speech here.