NASA Finds A Second Solar System As Big As Ours With The Help Of Google AI

NASA's Kepler space telescope has discovered an eighth planet in a distant star system called Kepler 90 - the first time a faraway star has been found to have the same number of planets orbiting it as our own sun. Although the Kepler 90 solar system is not new, the eighth planet, Kepler 90i, is, after it was found using AI software in a groundbreaking project between Google and NASA.

The discovery of a system similar to our own raises hopes of finding alien life elsewhere in the universe. The Kepler-90 planets have a similar configuration to our solar system, with small planets orbiting close to their star and the larger planets found farther away. According to NASA, this confirms for the first time that distant star systems can be home to 'families as large as our own.'  The new planet, estimated to be about 30 percent larger than Earth, is 'not a place you'd like to visit,' said Andrew Vanderburg, astronomer and NASA Sagan Postdoctoral Fellow at The University of Texas, Austin.
NASA's Kepler space telescope has discovered an eighth planet in a distant star system, tying our own solar system for the first time. The discovery in the Kepler-90 system was made possible with help from Google's advanced AI machine learning system. Pictured, the Kepler 90 system in its entirety, with Kepler 90i, the new planet, third from left. 

'It is probably rocky, and doesn’t have a thick atmosphere'. And, temperatures at the surface are 'scorching.'

According to Vanderburg, the average surface temperature is likely around 800 degrees Fahrenheit.  

The Kepler planet hunting satellite has been searching the stars for distant worlds using Google's AI system, which used machine learning to 'find' planets in the Kepler data with up to 96 percent accuracy. Neural networks can be trained on huge amounts of data to determine the difference between objects with great accuracy, the team explained in the teleconference.

How AI spotted Kepler 90i: The measured brightness of a star decreases ever so slightly when an orbiting planet blocks some of the light. The Kepler space telescope observed the brightness of 200,000 stars for 4 years to hunt for these characteristic signals caused by transiting planets 

Much like an AI can learn to spot the difference between cats and dogs, it can spot the difference between patterns associated with planets, and other types of patterns in the cosmos that could be false positives.

'After showing our model 15,000 signals, the neural network learned how to distinguish patterns from actual planets from patterns that are caused by other objects,' said Christopher Shallue, senior software engineer at Google AI in Mountain View, California.

He worked on the system as part of his '20 per cent time' at the company, where employees are allowed to work on anything they want.

'We used our model to identify two new planets from a set of 670 stars,' Shallue explained. One of these two planets is called Kepler 80g. The planet we are focusing on today is called Kepler 90i, which is the eighth planet in its star system. This is a really exciting discovery, and we consider it to be a success,' in the use of neural networks in the search for distant worlds, the expert explained. The star system sits roughly 2,545 light-years from Earth in the constellation Draco, and of the new planets found, Kepler 90i is the 'smallest of the bunch.'

The new planet orbits its star once every 14.4 days.

‘But, all of the planets in this system ‘tightly’ orbit their star, which is thought to be cooler than our own sun, meaning their orbital periods are relatively short. Before the latest AI-guided results, 'Kepler 90 was tied with Trappist-1, with 7 planets each,' says Jessie Dotson, Kepler project scientist at NASA's Ames Research Center in California’s Silicon Valley. But now, it ties with our own system with the most known number of planets' around a star.’

The Kepler 90 system was first discovered back in 2013. It was the first seven-planet system identified with the telescope. But, the eighth planet remained undetected for years – until Google’s AI picked up on its ‘weak’ signal.

The AI uses light readings from distant stars to identify potential signs of a planet – and, after training on thousands of previously vetted signals, it was able to spot the previously missed patterns of the elusive eight planet.

‘We get lots of false positives of planets, but also potentially more real planets,’ Vanderburg said. ’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.’The latest discovery is not just a planet candidate; according to NASA, the latest exoplanet has been confirmed to be 'almost certainly,' an exoplanet, with 1 in 10,000 false positive probability. While the discovery is exciting, this particular system isn’t the most promising for the possibility of hosting life. All of its planets are packed close to the star.

All eight planets of Kepler 90 sit closer to their host star than Earth is to the sun; in our own solar system, on the other hand, only Mercury and Venus have such tight orbits.

Kepler 90i is about as hot as Mercury, while the outermost planet in the system, Kepler 90h, is a gas giant roughly the size of Jupiter. The other newly discovered planet, Kepler-80g, is now known to be the sixth in the system. It’s roughly the size of Earth - and, its four neighbouring planets form a ‘resonant chain,’ which locks the planets into a rhythmic ‘orbital dance,’ that likely stabilizes the system.In its initial mission, Kepler surveyed just one patch of sky in the northern hemisphere, measuring the frequency of planets whose size and temperature might be similar to Earth orbiting stars similar to our sun. In the spacecraft's extended mission in 2013, it lost its ability to precisely stare at its original target area, but a fix created a second life for the telescope.

After the fix, Kepler started its K2 mission in 2014, which has provided an ecliptic field of view with greater opportunities for Earth-based observatories in both the northern and southern hemispheres. 

Because it covers more of the sky, the K2 mission is capable of observing a larger fraction of cooler, smaller, red-dwarf type stars.

No comments

Powered by Blogger.