Space

Astronomers identify most distant known object in the solar system

Astronomers identify most dist...
An artist's impression of Farfarout (bottom left), the new record holder for most distant known object in the solar system
An artist's impression of Farfarout (bottom left), the new record holder for most distant known object in the solar system
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An artist's impression of Farfarout (bottom left), the new record holder for most distant known object in the solar system
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An artist's impression of Farfarout (bottom left), the new record holder for most distant known object in the solar system
A chart showing the relative distances of objects in the solar system, with Farfarout taking the cake
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A chart showing the relative distances of objects in the solar system, with Farfarout taking the cake

For a long time, Pluto was the farthest object we knew about in the solar system, but it’s a cosmic stone’s-throw away compared to more recent discoveries. Now astronomers have confirmed what is currently the most distant world of all – the appropriately named Farfarout.

Provisionally designated 2018 AG37, Farfarout is an astonishing 132 Astronomical Units (AU) from the Sun, or almost 20 billion km (12.4 billion miles). For reference, Earth is 1 AU from the Sun, and even Pluto only gets to about 49 AU at its furthest. Farfarout also pips more recently discovered worlds like Farout, which now sounds positively close at “only” 124 AU, or the Goblin, which is currently 80 AU away.

Interestingly though, it may be the farthest known object in the solar system right now, but despite its name Farfarout doesn’t always hold the crown. It’s on an extremely eccentric 1,000-year orbit that swings it out to about 175 AU, and even that’s not the record, paling in comparison to the Goblin’s incredible 2,300 AU maximum distance. At its closest, Farfarout comes in to a mere 27 AU – that’s nearer to the Sun than Neptune.

A chart showing the relative distances of objects in the solar system, with Farfarout taking the cake
A chart showing the relative distances of objects in the solar system, with Farfarout taking the cake

“Farfarout was likely thrown into the outer solar system by getting too close to Neptune in the distant past," says Chad Trujillo, an author of a study describing the find. “Farfarout will likely interact with Neptune again in the future since their orbits still intersect.”

Farfarout was first discovered back in January 2018 by astronomers using the Subaru Telescope, but its exact distance couldn’t be determined. Being so far (far) out, the object is incredibly dim and moves very slowly across the sky. Further observations were needed to track its path and figure out its size.

In doing so, astronomers estimated that it’s about 400 km (250 miles) wide, which is much smaller than any officially recognized dwarf planet. Further study will be conducted to help determine its orbit and other characteristics more clearly.

And eventually, it will be given a more serious name than Farfarout and a less dry one than 2018 AG37.

Source: NOIRLab, University of Hawaii

9 comments
paul314
So about 1/2000 the way to Alpha Centauri. And the Goblin gets you about 1/100 the way. Ignoring all the obvious issues, you probably could do interstellar travel just by hopping from one cold rock to the next. (OK, maybe a really big few hops in the middle.)
Username
I see no need for a more serious name. How serious are the names of a fictional gods?
McDesign
I'm trying to imagine the tiny arc subtended by a 250-mile diameter, 12.4 million miles away. Hard to imagine the resolution needed to "see" it vs. measure its gravitational effects
alexD
the only benefit I see with these discoveries is to test telescopes, otherwise, no real benefits... so what's next ?? far-far-far-far-far-a-lot-far-out ?
btw, if one looks at the orbits of Neptune and Jupiter, one should notice that while Jupiter is quite away from us for our pity fire-farting rockets, Neptune is a staggering 5-times that same distance... yeah, Pluto is also far....
toni24
I am more interested in any large planets or planetoids in that new family in a different orbital plane than the one we grew up with.Is it possible that the legends of Nibaru and Tiamat are true
Mark T.
This "far out" labeling will not age well. Does anyone really believe there are not myriad further objects in the Scattered Disk and/or Oort Cloud? The current furthest object at 132 AU is almost certainly a function of telescope limitations, not the limit of what is really out there.
bwana4swahili
Will the next object be Farfarfarout? ... Or will opt for Far^3out?
Barry Ribbons
With present technology it would take us at least 10,000 years to reach the nearest stars.
Kirby Monroe
In a nod to "The Hitchhiker's Guide to the Galaxy", I think we should name this object "Rupert".