Astronomers discover a massive trans-Neptunian object 25,000 years from completing a single orbit — triggering a new era of deep space exploration
A distant celestial object, designated 2017 OF201, has just been identified orbiting the Sun from more than twice the distance of Pluto. Likely a dwarf planet, the discovery was made by astronomers at the Institute for Advanced Study in Princeton using years of data from top-tier observatories. This marks the most significant outer solar system object found in over a decade — and signals that dozens more may be hiding in plain sight.
What Makes 2017 OF201 So Special?
This isn’t just another rock floating past Neptune. Based on early estimates, 2017 OF201 spans 435 miles (700 km) in diameter — large enough to rival known dwarf planets like Gonggong and Haumea. But what truly sets it apart is its orbital behavior:
-
Aphelion (farthest point): Over 1,600x Earth’s distance from the Sun
-
Perihelion (closest point): 44.5x Earth’s distance — similar to Pluto
-
Orbital Period: ~25,000 years
Its wildly stretched path suggests a chaotic origin story — possibly flung from the inner solar system or even ejected from the Oort Cloud, then pulled back in.
Found Using Deep Sky Tools
Researchers pieced together its existence from 19 exposures over 7 years, captured by:
-
The Dark Energy Camera (Chile)
-
The Canada-France-Hawaii Telescope (Mauna Kea, Hawaii)
It spends only 1% of its orbit in a range detectable by today’s instruments, making the discovery a needle-in-a-haystack success.
Hundreds More May Exist
The object resides in the Kuiper Belt, a donut-shaped region beyond Neptune long assumed to be sparse. This discovery flips that idea — suggesting many Pluto-sized worlds may be silently orbiting the Sun, too far and too dim for us to detect yet.
According to lead astronomer Sihao Cheng, “The presence of this single object suggests that there could be another hundred or so others with similar orbit and size.”
That’s huge — because it expands our understanding of:
-
Dwarf planet formation
-
Solar system boundaries
-
The possible existence of Planet Nine or even unknown planetary systems beyond our current maps
