Recordfarthest Solar System object observedFarfarout[2]
About the image. Drawn as a small pinkish icy world, after Farout's measured pink colour. Neither object has been seen as more than a faint point of light; their sizes are estimates and the surface is imagined.
In November 2018 Scott Sheppard, David Tholen and Chad Trujillo, searching the sky with the 8.2-metre Subaru telescope in Hawaii for distant objects and for signs of Planet Nine, found a faint point of light moving extremely slowly. It was 123.4 times as far from the Sun as Earth, farther than anything in the Solar System had ever been seen. They nicknamed it Farout.
Farout
Farout, catalogued as 2018 VG18, has a pinkish colour, typical of ice-rich bodies in the outer Solar System. Its size can only be estimated from its brightness: probably 500 to 800 kilometres across. Follow-up observations pinned down its orbit, which takes about 737 years and carries it between 38 and 125 AU from the Sun. It was found close to its most distant point, which it will reach in 2063.
Farfarout
Farout’s record did not last long. In January 2018 the same team had already photographed an even fainter object, but it took until February 2021 to collect enough observations to confirm it. When first seen it was about 132 AU from the Sun. Inevitably, it was nicknamed Farfarout; its catalogue name is 2018 AG37.
Farfarout moves so slowly that its orbit is still uncertain. It probably takes about 700 years and ranges from about 28 AU, inside Neptune’s orbit, to about 133 AU. That orbit suggests it has been thrown outward by close encounters with Neptune. Its size, guessed from its faintness, is perhaps 400 to 600 kilometres.
Farthest seen, not farthest out
These are the most distant Solar System objects ever observed, but not the most distant ones known to orbit the Sun. Sedna, for example, is now heading towards its closest point to the Sun, 76 AU, but swings out to over 900 AU at the far end of its orbit. Objects that far out are simply too faint to find unless they happen to be near their closest approach.
How far out it would be
Seven planets, from 737 years to 717 years per orbit, all closer in than Mercury. Dashed circles show Jupiter, Saturn and Neptune around the Sun, on the same scale.
Earth days passing: 0
Gallery
A pale pink, frosty, cratered world lit from the left by the Sun, which is only a small bright star at that distance, an impression of Farout or Farfarout, the most distant objects seen in the Solar System. AI-generated painting.A pale pink frozen plain with a lump of frost under a black sky full of stars, the Sun only one small star among them, an impression of the surface of Farout or Farfarout. AI-generated painting.Farout and Farfarout, 3D artist's impression, rendered from the interactive model.Farout and Farfarout, 3D artist's impression, from another angle, rendered from the interactive model.Farout and Farfarout, 3D artist's impression, close-up, rendered from the interactive model.
Timeline
2018Farfarout is first photographed in January; Farout is found in November at 123.4 AU.
2021Farfarout is confirmed at about 132 AU, the most distant Solar System object observed.
2063Farout reaches its most distant point, about 125 AU.
Questions people ask
What is the farthest object in the Solar System?
The farthest ever observed is Farfarout, seen about 132 AU from the Sun. Objects such as Sedna travel much farther, but are too faint to see when they are far out.
How big is Farout?
Estimated at about 500–800 km across, from its brightness.