A UC Berkeley graduate student recently discovered a new solar system with three planets of similar size to Earth, using data from NASA’s Kepler Space Telescope.

Erik Petigura, a graduate student in UC Berkeley’s astronomy department, used computer algorithms to parse through NASA’s data. He then found a solar system that is close enough to Earth to be relatively easy to study and contains a planet that receives a comparable amount of starlight to Earth, meaning it may have a moderate, life-sustaining temperature.

Once Petigura discovered the planets, astronomers used telescopes in Hawaii, Chile and the UC-owned Lick Observatory near San Jose, California, to analyze the star around which the planets orbit — scientists use stars to examine the characteristics of planets.

“Kepler has found other systems, but they were farther away, and their stars were so faint that they were difficult to study,” said University of Hawaii at Manoa astronomer Andrew Howard. “Many of those problems are solved with the new solar system because the star is brighter and closer to Earth.”

The next step is to find this planet’s mass in order to determine its properties. If it has a low mass relative to its size, it is most likely gaseous and therefore more similar to a planet such as Neptune than to Earth.

Because the three planets are larger than Earth but smaller than Neptune, they could help illuminate information about the transition between small, rocky planets and big, gaseous ones, according to Ian Crossfield, the astronomer from University of Arizona who led the study on the discovery of the planets.

Astronomers can determine which molecules are in the atmosphere of a planet by analyzing the light that reaches it. If an atmosphere contains oxygen and nitrogen, it could be compatible with life.

For the last 20 years, scientists have been discovering planets in different solar systems at an exponential rate, Petigura said. Kepler has found more than 1000 of these since it was launched in 2009, according to its website.

The telescope, however, suffered severe hardware failures when two out of four of its reaction wheels stopped working properly, meaning it was unable to take accurate pictures, according to Petigura. Yet NASA scientists found a way to continue to use the machine, which is now operating in a new mode called K2.

Crossfield said this discovery is a sign that the K2 mission is likely to find more planetary systems to study and follow up on.

“The normal operation mode of the spacecraft was compromised, but thanks to ingenious work at NASA, they found a way to continue to use Kepler,” Petigura said. “The data coming down aren’t as high quality as they used to be, so my role is to take the data and clean it up.”