A newly discovered object is the most-distant body ever observed in the solar system — and the first object ever found orbiting at more than 100 times the distance from Earth to the sun. "This discovery is truly an international achievement in research using telescopes located in Hawaii and Chile, operated by Japan, as well as a consortium of research institutions and universities in the United States," Chad Trujillo, a researcher at Northern Arizona University and the third member of the discovery team, said in the statement. (Image credit: Roberto Molar Candanosa/Carnegie Institution for Science)

Farout is 120 astronomical units (AU) from the sun — one AU is the distance between Earth and the sun, which is about 93 million miles (150 million kilometers). A statement from these astronomers explained:

The second-most-distant observed solar system object is Eris, at about 96 AU. The object is more than 3.5 times the current distance between Pluto and the sun (34 AU), and it outpaces the previous farthest-known solar system object, the dwarf planet Eris, which is currently about 96 AU from the sun. (Image credit: Roberto Molar Candanosa/Carnegie Institution for Science)

The research team is scoping out these ultradistant objects to search for the gravitational influence of a theorized super-Earth-size Planet Nine, also called Planet X, that researchers have posited orbits in the extreme reaches of the solar system. “With new wide-field digital cameras on some of the world’s largest telescopes, we are finally exploring our Solar System’s fringes, far beyond Pluto.”

In October, the team announced the discovery of “the Goblin” at 80 AU; it’s so named because the distant solar system object was first spotted near Halloween. Their statement explained:

The Goblin was discovered at about 80 AU and has an orbit that is consistent with it being influenced by an unseen super-Earth-sized Planet X on the solar system’s very distant fringes … 2015 TG387 and 2012 VP113 never get close enough to the solar system’s giant planets, like Neptune and Jupiter, to have significant gravitational interactions with them. This hypothetical planet is thought to exist in the outer reaches of the Solar System because of the way other Kuiper Belt objects are orientated. “Planet X is also likely even further away, at a few hundred AU.”

It’s reasonable to wonder how this object managed to stray so far from the Solar System’s planetary pack; astronomers won’t know the answer to this question until Farout’s orbit can be determined. "2018 VG18 is much more distant and slower moving than any other observed solar system object, so it will take a few years to fully determine its orbit," Scott Sheppard, a researcher at the Carnegie Institution for Science in Washington, D.C., and member of the discovery team, said in the statement. “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,” explained Sheppard. The orbital similarities shown by many of the known small, distant Solar System bodies was the catalyst for our original assertion that there is a distant, massive planet at several hundred AU shepherding these smaller objects.”

“All that we currently know about 2018 VG18 is its extreme distance from the Sun, its approximate diameter, and its color,” added Tholen “Because 2018 VG18 is so distant, it orbits very slowly, likely taking more than 1,000 years to take one trip around the Sun.”

The discovery images of 2018 VG18 were taken at the Japanese Subaru 8-meter telescope located atop Maunakea in Hawai‘i on Nov. 10, 2018. “All that we currently know about 2018 VG18 is its extreme distance from the Sun, its approximate diameter, and its color,” said University of Hawaii astronomer David Tholen.”Because 2018 VG18 is so distant, it orbits very slowly, likely taking more than 1,000 years to take one trip around the Sun.”

The new object was announced on Monday, December 17, 2018, by the International Astronomical Union’s Minor Planet Center and has been given the provisional designation 2018 VG18. The discovery images of 2018 VG18 were taken at the Japanese Subaru 8-metre telescope located atop Mauna Kea in Hawaii on November 10, 2018. “With new wide-field digital cameras on some of the world’s largest telescopes, we are finally exploring our Solar System’s fringes, far beyond Pluto.”

The Subaru telescope is owned and operated by Japan and the valuable telescope access that the team obtained was thanks to a combination of time allocated to the University of Hawai‘i, as well as to the U.S. National Science Foundation (NSF) through telescope time exchanges between the US National Optical Astronomy Observatory (NOAO) and National Astronomical Observatory of Japan (NAOJ). The Magellan observations confirmed that 2018 VG18 is around 120 AU, making it the first Solar System object observed beyond 100 AU. But the researchers who found it are calling it “Farout.”

They believe the spherical object is a dwarf planet more than 310 miles in diameter, with a pinkish hue. It has a pinkish hue, a color generally associated with ice-rich objects, the researchers say.
Astronomers announce the discovery of trans-Neptunian object 2018 VG18, the most distant object in the Solar System ever observed at a distance of ~120 AU.