Nasa has found an entire solar system with as many planets as our own.

The discovery of a new planet around the Kepler-90 star, which looks like our own sun, means the distant solar system has a total of eight known planets. And those planets look like those in our own neighbourhood: rocky planets orbit close to the star, with gas giants further away.

The star and its family of planets were already known about, having been detected by the Kepler space telescope. But the breakthrough came when astronomers found the new world, which was done using Google’s artificial intelligence technology.

Nasa's most stunning pictures of space Show all 30 1 /30 Nasa's most stunning pictures of space Nasa's most stunning pictures of space Solar Flare An image from Nasa's Solar Dynamics Observatory (SDO) shows a 200,000 mile long solar filament ripping through the Sun's corona in September 2013 Nasa Nasa's most stunning pictures of space Nasa Celebrates 50 Years of Spacewalking For 50 years, NASA has been "suiting up" for spacewalking. In this 1984 photograph of the first untethered spacewalk, NASA astronaut Bruce McCandless is in the midst of the first "field" tryout of a nitrogen-propelled backpack device called the Manned Maneuvering Unit (MMU) Nasa Nasa's most stunning pictures of space A Hubble Cosmic Couple The spectacular cosmic pairing of the star Hen 2-427 — more commonly known as WR 124 — and the nebula M1-67 which surrounds it ESA/Hubble & NASA Nasa's most stunning pictures of space Veil Nebula Supernova Remnant Nasa's Hubble Space Telescope has unveiled in stunning detail a small section of the Veil Nebula - expanding remains of a massive star that exploded about 8,000 years ago Nasa's most stunning pictures of space The Soyuz TMA-15M rocket launch The Soyuz TMA-15M rocket launches from the Baikonur Cosmodrome in Kazakhstan on Monday, Nov. 24, 2014, carrying three new astronauts to the International Space Station. It also took caviar, ready for the satellite's inhabitants to celebrate the holidays Nasa Nasa's most stunning pictures of space Earth from the ISS From the International Space Station, Expedition 42 Flight Engineer Terry W. Virts took this photograph of the Gulf of Mexico and U.S. Gulf Coast at sunset Nasa Nasa's most stunning pictures of space Black Hole Friday Nasa celebrated Black Friday by looking into space instead — sharing pictures of black holes Nasa Nasa's most stunning pictures of space NuSTAR X-rays stream off the sun in this image showing observations from by NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, overlaid on a picture taken by NASA's Solar Dynamics Observatory (SDO) Nasa Nasa's most stunning pictures of space Cassiopeia A c A false colour image of Cassiopeia A comprised with data from the Spitzer and Hubble Space Telescopes and the Chandra X-Ray observatory Nasa Nasa's most stunning pictures of space Orion Capsule splashes down The Orion capsule jetted off into space before heading back a few hours later — having proved that it can be used, one day, to carry humans to Mars Nasa Nasa's most stunning pictures of space Earth Observations From Gemini IV in 1965 This photograph of the Florida Straits and Grand Bahama Bank was taken during the Gemini IV mission during orbit no. 19 in 1965. The Gemini IV crew conducted scientific experiments, including photography of Earth's weather and terrain, for the remainder of their four-day mission following Ed White's historic spacewalk on June 3 Nasa's most stunning pictures of space Frosty slopes of Mars This image of an area on the surface of Mars, approximately 1.5 by 3 kilometers in size, shows frosted gullies on a south-facing slope within a crater. The image was taken by Nasa's HiRISE camera, which is mounted on its Mars Reconaissance Orbiter Nasa Nasa's most stunning pictures of space Yellowstone from space NASA astronaut Reid Wiseman shared this image of Yellowstone via his twitter account Nasa Nasa's most stunning pictures of space Saturn This near-infrared color image shows a specular reflection, or sunglint, off of a hydrocarbon lake named Kivu Lacus on Saturn's moon Titan Nasa Nasa's most stunning pictures of space Worlds Apart Although Mimas and Pandora, shown here, both orbit Saturn, they are very different moons. Pandora, "small" by moon standards (50 miles or 81 kilometers across) is elongated and irregular in shape. Mimas (246 miles or 396 kilometers across), a "medium-sized" moon, formed into a sphere due to self-gravity imposed by its higher mass Nasa Nasa's most stunning pictures of space Solar Flare An X1.6 class solar flare flashes in the middle of the sun in this image taken 10 September, captured by NASA's Solar Dynamics Observatory Nasa Nasa's most stunning pictures of space Large Magellanic Cloud galaxy An image of the Large Magellanic Cloud galaxy seen in infrared light by the Herschel Space Observatory. Regions of space such as this are where new stars are born from a mixture of elements and cosmic dust Nasa Nasa's most stunning pictures of space Mars Rover Spirit Nasa's Mars Rover Spirit took the first picture from Spirit since problems with communications began a week earlier. The image shows the robotic arm extended to the rock called Adirondack Nasa Nasa's most stunning pictures of space Morning Aurora From the Space Station Nasa astronaut Scott Kelly captured this photograph of the green lights of the aurora from the International Space Station Nasa/Scott Kelly Nasa's most stunning pictures of space Launch of History - Making STS-41G Mission in 1984 The Space Shuttle Challenger launches from Florida at dawn. On this mission, Kathryn Sullivan became the first U.S. woman to perform a spacewalk and Marc Garneau became the first Canadian in space. The crew of seven was the largest to fly on a spacecraft at that time, and STS-41G was the first flight to include two female astronauts Nasa's most stunning pictures of space A Fresh Perspective on an Extraordinary Cluster of Galaxies Galaxy clusters are often described by superlatives. After all, they are huge conglomerations of galaxies, hot gas, and dark matter and represent the largest structures in the Universe held together by gravity Nasa's most stunning pictures of space Hubble Sees a Galactic Sunflower The arrangement of the spiral arms in the galaxy Messier 63, seen here in an image from the Nasa Hubble Space Telescope, recall the pattern at the center of a sunflower ESA/Hubble & NASA Nasa's most stunning pictures of space Pluto image Four images from New Horizons’ Long Range Reconnaissance Imager (LORRI) were combined with colour data from the Ralph instrument to create this enhanced colour global view of Pluto Nasa's most stunning pictures of space Fresh Crater Near Sirenum Fossae Region of Mars The HiRISE camera aboard Nasa's Mars Reconnaissance Orbiter acquired this closeup image of a "fresh" (on a geological scale, though quite old on a human scale) impact crater in the Sirenum Fossae region of Mars. This impact crater appears relatively recent as it has a sharp rim and well-preserved ejecta Nasa's most stunning pictures of space Hubble Peers into the Most Crowded Place in the Milky Way This Nasa Hubble Space Telescope image presents the Arches Cluster, the densest known star cluster in the Milky Way NASA & ESA Nasa's most stunning pictures of space An Astronaut's View from Space Nasa astronaut Reid Wiseman tweeted this photo from the International Space Station on 2 September 2014 Nasa's most stunning pictures of space Giant Landform on Mars On Mars, we can observe four classes of sandy landforms formed by the wind, or aeolian bedforms: ripples, transverse aeolian ridges, dunes, and what are called “draa” Nasa's most stunning pictures of space Expedition 39 Landing A sokol suit helmet can be seen against the window of the Soyuz TMA-11M capsule shortly after the spacecraft landed with Expedition 39 Commander Koichi Wakata of the Japan Aerospace Exploration Agency (JAXA), Soyuz Commander Mikhail Tyurin of Roscosmos, and Flight Engineer Rick Mastracchio of NASA near the town of Zhezkazgan, Kazakhstan (NASA/Bill Ingalls) Nasa's most stunning pictures of space Jupiter's Great Red Spot Viewed by Voyager I Jupiter is the largest planet in the solar system and perhaps the most majestic. Vibrant bands of clouds carried by winds that can exceed 400 mph continuously circle the planet's atmosphere Nasa's most stunning pictures of space Chandra Observatory Sees a Heart in the Darkness This Chandra X-Ray Observatory image of the young star cluster NGC 346 highlights a heart-shaped cloud of 8 million-degree Celsius gas in the central region

A computer was trained to look through the data from the Kepler space telescope, and look for signals that might belong to planets. And it found new planets within existing systems, by spotting signals that seemed to indicate something of interest but were too weak to have been spotted by humans.

That suggests that there might be whole worlds and solar systems hiding within the data we’ve already collected, but which we had not noticed because there are simply so many signals to pick through. Kepler has collected four-years of data from looking at the sky and 150,000 stars – far more than humans could ever look through.

“Just as we expected, there are exciting discoveries lurking in our archived Kepler data, waiting for the right tool or technology to unearth them,” said Paul Hertz, director of Nasa’s astrophysics division in Washington. “This finding shows that our data will be a treasure trove available to innovative researchers for years to come.”

Researcher Andrew Vanderburg said he would be surprised if there was not even more planets lurking to add to the newly discovered systems. He also said that it “almost certainly won’t be the last” system that has eight planets, suggesting our own solar system is not really all that extraordinary.

(Nasa/JPL (Nasa/JPL)

Indeed, the Kepler-90 system might have more planets in it that we have not been able to spot yet. The same has been suggested of our own solar system – leading the two to be linked in a race to find which of them might in fact be bigger.

The planets in the solar system are much more close together than they are in our own, but it is very stable. “The Kepler-90 star system is like a mini version of our solar system. You have small planets inside and big planets outside, but everything is scrunched in much closer,” said Vanderburg, a Nasa Sagan postdoctoral fellow and astronomer at the University of Texas at Austin.

The Kepler-90 system is 2,500 lightyears away and is not a particularly good candidate for finding life. But the discovery about the sheer number of planets in each solar system does improve the chances of finding it, simply by suggesting that there could be far more exoplanets than we ever thought.

At the same time as they found the important new Kepler-90 planet – described as a sizzling-hot world that orbits around its star every 14.4 days – astronomers also found another planet around the Kepler-80 star.

The new planets – just like all of the thousands found by Kepler – were spotted by watching the sky for light coming from the stars. When planets pass in front of their stars, scientists can register the dimming as they go, and use the speed and characteristics of that dimming to work out what the solar system might actually look like.

To train up the algorithms, the Google AI was shown 15,000 signals that have already been checked. It could then look through other, unverified data and look for those same patterns. This is thought to be the first time that neural networks of this kind were used to find planets in the Kepler data.

Scientists hope to use that same AI technology with the rest of the Kepler data set, as well as data from other telescopes. Kepler has been looking at one patch of space for four years, but is now moving around the rest of the sky and sending further information back down to Earth – all of which contains potential planets, and so will benefit from being looked at by Google’s artificial intelligence.