A giant new haul of planets outside the solar system has been added to the list of those found by the ongoing Kepler missions. Led by the University of Arizona, an international team of astronomers has confirmed the existence of 104 exoplanets. It marks the biggest collection of planets discovered by the K2 mission, the Kepler space telescope's second round of planet-hunting.
The new planets bring the number of confirmed Kepler planets to 3,473.
"This allows the astronomical community ease of follow-up and characterisation, and picks out a few gems for first study by the James Webb Space Telescope, which could perhaps provide information about their atmospheres," said Steve Howell, project scientist for Kepler and K2 at NASA's Ames Research Center in Mountain View, California.
Kepler finds exoplanet candidates by studying the stars, looking for regular dips in their brightness levels. These are caused by planets orbiting between Kepler and the star. The planets are confirmed by follow-up observation of these stars by ground-based telescopes. In the case of this study, the team used the Gemini North telescope and the W.M. Keck Observatory in Hawaii, the Automated Planet Finder in California, and the Large Binocular Telescope in Arizona. Of the 197 candidate planets Kepler identified, the team confirmed 104.
At least four of the new batch of planets could be rocky planets, like Earth or Mars. These four planets are located 181 light-years from Earth in the direction of the constellation Aquarius, orbiting a star less than half the size of the sun. They are all between 20 and 50 percent larger than Earth's diameter and have very orbits between 5.5 and 24 days. Although their orbit is so tight, they are still potentially within K2-72's "Goldilocks zone" -- that is, not too cold and not too hot to support life.
More research will need to be conducted on the planets to determine how many of them could support the conditions for the emergence of life.