Exoplanet hunting has become a dedicated field of astronomy ever since 1995 when European astronomers Michel Mayor and Didier Queloz discovered a planet outside of our own solar system orbiting around its own sun-like star. To date, we’ve uncovered 3,600 of these planets, and scientists believe billions more lurk in the Milky Way.
An international team of researchers from institutions including NASA, Caltech, Denmark, and the University of California, Berkeley, today added 95 new exoplanets to the list. The discovery, published in Astronomical Journal, was made possible by data collected by the Kepler Space Telescope. NASA launched Kepler in 2009 and rechristened it “K2” in 2013 after a mechanical failure changed the nature of its operation.
To uncover exoplanets, K2 orbits the earth and fixes its gaze on different patches of sky. It records the light levels of hundreds of thousands of stars in search of characteristic light fluctuations that occur when exoplanets cross in front of their host stars. Since K2’s first data release in 2014, researchers have been combing through the light signals to separate the fluctuations caused by exoplanets from those caused by other sources. The team behind today’s discovery began with 275 candidates. They confirmed 149 as real exoplanets, of which 95 proved to be new discoveries.
“We found that some of the signals were caused by multiple star systems or noise from the spacecraft,” said Andrew Mayo, an American PhD student at the National Space Institute of the Technical University of Denmark and the publication’s lead author. “But we also detected planets that range from sub Earth-sized to the size of Jupiter and larger.”
Exoplanet explorers want to find other Earth-sized planets that may be capable of supporting life. Upcoming space missions like NASA’s James Webb Space Telescope and the Transiting Exoplanet Survey Satellite will take major steps to characterize and study such habitable, Earth-like planets.
“Exoplanets are a very exciting field of space science,” said Mayo. “As more planets are discovered, astronomers will develop a much better picture of the nature of exoplanets, which in turn will allow us to place our own solar system into a galactic context.”