Alien solar system ties ours for largest in a discovery aided by AI

Alien solar system ties ours for largest in a discovery aided by AI

NASA’s Kepler Space Telescope has been searching for exoplanets, or planets that exist outside our own solar system, since it launched in 2009. Thursday it was announced that a previously undiscovered eighth planet was discovered orbiting a star 2,500 light years away, named Kepler-90i, after the star it orbits

“This discovery of an eighth planet ties Kepler-90 with our own solar system for having the most known planets,” said NASA astrophysicist Paul Hertz.

The planet is thought to be about 30 percent larger than Earth and is so close to its star that its average temperature is believed to be like that of Mercury, exceeding 800 degrees Fahrenheit.

The discovery comes with the help of artificial intelligence help from a Google neural network trained to identify weak signals, developed by University of Texas at Austin astronomer Andrew Vanderburg and Google software engineer Christopher Shallue.

“New ways of looking at the data – such as this early-stage research to apply machine learning algorithms – promises to continue to yield significant advances in our understanding of planetary systems around other stars.” said Jessie Dotson, Kepler’s project scientist at NASA’s Ames Research Center in the NASA press release.

According to Wired, Kepler took pictures between 2009 and 2013 of 200,000 stars, looking for repeating cycles of dimming and brightening. These cycles are good indicators that a planet is orbiting the star, and based on the time it takes to dim and how quickly it brightens, information on length of orbit and size of the planet can be extrapolated.

In the dataset compiled by Kepler over its four-year missio,n 35,000 possible planetary signals were identified.

First the neural network was trained to identify previously verified signals and it was able to correctly identify true planets and false positives 96 percent of the time. Once it had “learned” to detect known exoplanet patterns the scientist unleashed it on a series of weaker signals from systems known to already contain planets.

“We got lots of false positives of planets, but also potentially more real planets. It’s like sifting through rocks to find jewels. If you have a finer sieve then you will catch more rocks but you might catch more jewels, as well,” said Vanderburg.

However Keppler-90i wasn’t the only discovery made through the machine learning sifting. Another “jewel,” an Earth-sized sixth planet locked in a “rhythmic orbital dance” with four of its neighboring planets, was found in the Kepler-80 system.

These results demonstrate the enduring value of Kepler’s mission,” said Dotson. A research paper on the findings was accepted for publication in The Astronomical Journal.