Astronomers Just Found the Most Distant Object in Our Solar System, So They Named It 'Farout'

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This illustration shows what the space object dubbed 'Farout' might look like. Roberto Molar Candanosa/Carnegie Institution for Science

The Proclaimers famously swore to walk 500 miles and walk 500 more to show the depth of their love — but that's nothing compared to the dedication required for this task. If you wanted to see the most distant known object in our solar system, you'd have to walk 120 astronomical units. (And by the way, 1 astronomical unit or AU is 93 million miles.)

But for one group of astronomers, the investment in shoes would be well worth it.

The discovery of the object, provisionally named 2018 VG18 but dubbed "Farout," was announced Dec. 15 by the International Astronomical Union's Minor Planet Center. The same group of researchers who spotted Farout also discovered another far-off object they nicknamed "the Goblin" in October.

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Before the discovery of Farout, the most distant known object in our solar system was Eris, a dwarf planet discovered in 2005, located some 96 AUs from the sun. Goblin is about 80 AUs.

Farout was originally discovered Nov. 10 using the Japanese Subaru 8-meter telescope located at Mauna Kea in Hawaii. The object was observed again early in December, this time by the Magellan telescope at the Las Campanas Observatory in Chile. Both observations confirmed the object's brightness, color, size and path across the night sky. Researchers believe, based on its brightness, that Farout is about 310 miles (500 kilometers) in diameter, likely making it a spherical dwarf planet. It also has a pinkish hue, suggesting that Farout is an ice-rich object.

A scale shows the respective distance in astronomical units between the sun and other objects in space
This scale shows, in astronomical units, the distance from the sun to other known bodies in our solar system. Roberto Molar Candanosa and Scott S. Sheppard/Carnegie Institution for Science

And that's basically the extent of what we know about Farout. It'll be a while before we know more, like full the path of its orbit.

"All that we currently know about 2018 VG18 is its extreme distance from the Sun, its approximate diameter, and its color," one of Farout's discoverers, David Tholen from the University of Hawaii, said in a statement. "Because 2018 VG18 is so distant, it orbits very slowly, likely taking more than 1,000 years to take one trip around the sun."

Proof of Planet X?

Like with Goblin, Farout's discovery was part of a project to locate the elusive Planet X, a super-Earth-sized body that may be located somewhere on the fringes of our solar system. Since we don't know much about Farout's orbit yet, it's too soon to tell if the hypothetical Planet X is exerting force on Farout's orbit.

Planet X, also referred to as Planet 9, has been proposed because of the unusual orbits of smaller bodies like Goblin and Farout. To exert pressure on their orbit's, Planet X would have to be roughly the size of Neptune with a mass 10 times that of Earth's, according to NASA. This planet would require between 10,000 and 20,000 years to complete a single orbit around the sun.

"Planet X needs to be several times larger than Earth in order to gravitationally push the other smaller objects around and shepherd them into similar types of orbits," the Carnegie Institute for Science's Scott Sheppard told Gizmodo. "Planet X is also likely even further away, at a few hundred AU." Sheppard was another of Farout's discoverers.

Spotting bodies like Farout and Goblin could lead astronomers one step closer to discovering Planet X.

The search continues.