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With the discovery of an eighth planet, the Kepler-90 system is the first to tie with our solar system in number of planets. Photo: NASA/Wendy Stenzel

The cosmos is vast; so vast the human eye has come to rely on an increasingly diverse toolbox of telescopes and spacecraft and computers to look farther and farther out into the unknown of space.

Today, NASA and computing giant Google have jointly announced that a machine-learning system they built has discovered the eighth planet orbiting around a star called Kepler-90, a star similar to our sun that holds the potential of hosting life somewhere in its solar system.

NASA and Google announced their findings, which have also been accepted for publication by The Astronomical Journal. The space agency is holding a Reddit “Ask Me Anything” this afternoon.

The planet Kepler-90i now makes the solar system the first to be identified with as many planets as our own - at a distance of more than 2,500 light-years from us.

It was the neural network developed by Christopher Shallue of Google and Andrew Vanderburg that saw the first clues of the eighth planet. The dataset fed into the system was four years including 35,000 possible planetary signals. The exoplanet identification accurate rate was estimated at 96 percent, when the computer was trained to look for clues.

When it assessed the Kepler-90 system, the neural network identified some weak signals as an object crossed past the light of the far-off star.

“Machine learning really shines in situations where there is so much data that humans can’t search it for themselves,” said Shallue.

“We have statistically validated this candidate,” said Andrew Vanderburg, an astronomer and NASA Sagan postdoctoral fellow at the University of Texas, Austin.

“We got lots of false positives of planet, 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,” Vanderburg added.

This eighth planet called Kepler-90i is likely to be an incredibly hot (800 degree Fahrenheit) and mostly rocky planet that orbits its star one every 14 days or so, according to the research.

Shallue and Vanderburg plan to try the neural network’s analysis to the Kepler full data set of approximately 150,000 stars, they said.

The Kepler spacecraft mission was launched in 2009, and has essentially revolutionized the search for planets outside our solar system that can support life.

Kepler now has observed more than 2,000 exoplanets since its launch in 2009.

“That’s a pretty good haul,” said Dotson.

In 2015, NASA announced the discovery of an “Earth 2.0” that had many of the same criteria as our own planet. Kepler-452b is some 1,400 light years away in the constellation Cygnus, is 60 percent bigger than Earth and has a 385-day orbit around its star, which is similar to our own, the agency announced last July.

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