NASA’s Kepler Mission has just boosted the exoplanet count by a hefty 1,284 in an unprecedented feat. The collection of alien planets verified by NASA’s Kepler team is the largest number discovered so far.
Nearly 5,000 possible exoplanets have been found so far, and nearly half of them were discovered by the Kepler Telescope. The figure puts the total number of exoplanets confirmed by the Kepler Mission at 2,326. The Kepler planet catalog, compiled in July 2015, contains many more possible planet readings to be verified – a total of 4,302 including those mentioned in today’s announcements.
The Kepler Space Telescope uses high precision photometry to view the light generated by 150,000 stars all at once. Over a period of about four years, Kepler observed small fluctuations in the light emanating from stars that are caused by planets in orbit. Yesterday’s Mercury transit, where Mercury could be observed passing before our sun as a dark blip, illustrates the same phenomenon.
NASA’s theory is that habitable exoplanets will exist within a certain zone of a star system, orbiting their respective stars at a distance roughly the equivalent of the inner solar system. It is believed that exoplanets within that zone, closer to their own sun, will be more likely to exhibit earth-like atmosphere, weather, and other physical characteristics. That habitable zone is where the Kepler Space Telescope made its observations.
NASA uses a number of variables to verify the existence of planets from the resulting readings. If the probability is greater than 99 percent, NASA considers it verified as a planet. Today’s news changes scientists’ understanding of the make up of the galaxies and universe. Paul Hertz, Astrophysics Division director at NASA Headquarters, commented in a media release.
“Before the Kepler space telescope launched, we did not know whether exoplanets were rare or common in the galaxy. Thanks to Kepler and the research community, we now know there could be more planets than stars.”
With a goal of finding habitable exoplanets, Kepler’s data will be used to design future NASA missions on the hunt for living alien worlds. The Kepler Mission has brought NASA a number of firsts in the world of astronomy. Just last July, NASA announced that the Kepler team had discovered what they called a “bigger, older cousin to Earth” or the closest thing yet to Earth 2.
Among the 1,824 planets verified in today’s announcement, about 550 feature a rocky composition similar to Earth and are similar in size. It seems to make the dream of finding Earth 2 that much closer to reality. Ellen Stofan, chief scientist at NASA Headquarters in Washington is quoted in the today’s NASA press release.
“This announcement more than doubles the number of confirmed planets from Kepler. This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth.”
As a piece in Forbes points out, there are limitations to what NASA’s Kepler Mission can observe. For example, the Kepler Space Telescope can only view fluctuations in the light of stars that are within its line of sight.
That means, as many as Kepler has found so far, the actual number of exoplanets is probably much, much higher. Estimates put the number of rocky, habitable exoplanets at 60 billion in our galaxy alone. The Forbes article cites theoretical research that now postulates that there is not only one Earth 2 or even several, but that the probability of so many habitable exoplanets must mean that humanity is not the only species to have developed technology. Could there be aliens searching for us too?
NASA’s Kepler Mission
NASA’s Kepler Space Telescope – often dubbed the “planet hunter” – was launched in 2009 and orbits the sun every 371 days, taking just a little longer than Earth.
Just a month ago, NASA’s Kepler Mission ran into trouble after the ground team lost contact with the spacecraft, which was then 75 million miles from Earth. The Kepler Mission entered emergency mode during the first week of April, but NASA was able to rescue the mission, re-establish contact and bring it back on track after a few tense days.
Today’s announcement verifies that the results were worth NASA’s efforts in keeping Kepler – and the hunt for Earth 2 – alive.
[Image via NASA Ames/W. Stenzel]