Galaxy grows as 715 planets found
WASHINGTON — The Earth’s galaxy is looking far more crowded and hospitable. NASA on Wednesday confirmed a bonanza of 715 newly discovered planets outside the solar system.
Scientists using the planet-hunting Kepler telescope pushed the number of planets discovered in the galaxy to about 1,700.
Twenty years ago, astronomers had not found any planets circling stars other than the ones revolving around the sun.
“We almost doubled just today the number of planets known to humanity,” NASA planetary scientist Jack Lissauer said in a Wednesday teleconference, calling it “the big motherlode.”
Astronomers used a new confirmation technique to come up with the largest single announcement of a batch of exoplanets, as planets outside our solar system are called.
While Wednesday’s announcements were about big numbers, they also were about implications for life behind those big numbers.
All the new planets are in systems like ours in which multiple planets circle a star. The 715 planets came from looking at just 305 stars.
They were nearly all closer in size to Earth than to gigantic Jupiter.
And four of those new exoplanets orbit their stars in “habitable zones” where it is not too hot or not too cold for liquid water, which is crucial for life to exist.
Douglas Hudgins, NASA’s exoplanet exploration program scientist, called Wednesday’s announcement a major step toward Kepler’s ultimate goal: “finding Earth 2.0.”
So far Kepler has found nine exoplanets in the habitable zone, NASA said.