A new discovery at the edge of our solar system is turning heads in the astronomy world—and could reshape how we think about the outer reaches of space.
Astronomers have identified a distant object known as 2017 OF201, a minor planet located beyond Pluto, according to Gizmodo. Measuring between 290 and 510 miles in diameter, it’s small compared to major planets but still massive enough to be classified as a trans-Neptunian object (TNO)—a body that orbits the Sun past Neptune.
The discovery was led by Sihao Cheng, the Martin A. and Helen Chooljian Member in the School of Natural Sciences at the Institute for Advanced Study, as reported by Phys.org. The International Astronomical Union’s Minor Planet Center has officially added 2017 OF201 to its registry, marking it as a legitimate celestial body of interest.
What makes this object so fascinating is its extreme orbit.
“The object’s aphelion—the farthest point on the orbit from the sun—is more than 1600 times that of Earth’s orbit,” Cheng said. “Meanwhile, its perihelion—the closest point on its orbit to the sun—is 44.5 times that of Earth’s orbit, similar to Pluto’s orbit.”
In other words, 2017 OF201 is incredibly far away—838 astronomical units (AU) from the Sun, which puts it nearly 30 times farther out than Neptune (which itself orbits about 30 AU from the Sun). This makes 2017 OF201 one of the most remote solar system objects ever observed.
Even more mind-blowing: scientists found it by digging through archived telescope images, not by using new observations. And yet, despite being found in old data, it’s only visible from Earth about one percent of the time due to the vastness of its orbit.
“The presence of this single object suggests that there could be another hundred or so other objects with similar orbit and size; they are just too far away to be detectable now,” Cheng explained.
The revelation opens the door to a potentially vast, hidden population of minor planets lurking far beyond Pluto—some of which may offer new insights into how our solar system formed and evolved. For now, 2017 OF201 is a small but significant clue in the hunt for what might still be out there.
