-
New Horizons—the famous NASA spacecraft that flew by Pluto in 2015—is now making new discoveries beyond the Kuiper Belt.
-
With help from the Subaru telescope in Hawaii, scientists have discovered what could be a second belt of icy bodies beyond the known Kuiper Belt.
-
This possible discovery only highlights how much more there is to learn about our Solar System beyond the reaches of Neptune.
With the James Webb Space Telescope in orbit at Lagrange point 2, roughly 1 million miles from Earth, humanity’s view of the universe now extends some 13.5 billion years into the past. And while astronomers and cosmologists are eager to study the early days of everything, there’s still a lot we don’t know about our own stellar neighborhood.
We know that the Earth orbits the Sun (thanks for that one, Copernicus), and that our star hosts eight full-fledged planets (sorry about that one, Pluto). But astronomers still only have a fuzzy picture of what lies beyond the reaches of Neptune. In 1951, Dutch-American astronomer Gerard Kuiper hypothesized that a belt of objects must lie beyond the most distant planet, and that prediction proved true in 1992 with the discovery of the Kuiper Belt. Now, mounting evidence suggests that a second Kuiper Belt might even lie beyond this first one. A study detailing this discovery, which will be published in the Planetary Science Journal, was recently published on the pre-print server arXiv.
“Our Solar System’s Kuiper Belt long appeared to be very small in comparison with many other planetary systems,” Wes Fraser, the lead author of the study from the National Research Council of Canada, said in a press statement, “but our results suggest that idea might just have arisen due to an observational bias. So maybe, if this result is confirmed, our Kuiper Belt isn’t all that small and unusual after all compared to those around other stars.”
These results come from a joint effort of the New Horizons probe—which famously flew by Pluto back in 2015—and the 8-meter Subaru telescope Mauna Kea, which sits atop the mountain from which it gets its name and has been searching for potential Kuiper Belt objects (KBOs) for New Horizons to visit. For years, Subaru’s search for objects was complicated by being located in front of the dense background of the galaxy’s center. But now that it’s located in a sparse region of the sky, the telescope’s Hyper Suprime-Cam has spotted 239 KBOs in just four years. Of those, about a dozen are particularly interesting.
“The most exciting part of the HSC was the discovery of 11 objects at distances beyond the known Kuiper Belt,” Fumi Yoshida, a co-author of the study from the Chiba Institute of Technology, said in a press statement. “If this is confirmed, it would be a major discovery.”
Their unique nature has to do with their relative distance from both the Sun and the “first” Kuiper Belt, which lies roughly 35 to 55 astronomical units (AU) out from the center of our Solar System (one AU is the average distance from the Earth to the Sun). However, according to Space.com, these newly discovered objects lie between 70 and 90 AU from the Sun.
So, why aren’t these farflung KBOs considered part of the (much larger than expected) original Kuiper Belt? Well, there appears to be a gap of objects located between 55 AU and 70 AU from the Sun (New Horizons is currently located at around 60 AU from the Sun). That means these 11 objects appear to be forming a defined second ring around the Solar System.
The researchers say they’ll continue to track these objects while searching for more like them, and considering that these are clustered in a small part of the sky, there are likely many more out there. Upcoming surveys—especially the Legacy Survey of Space and Time (LSST) at the Vera C. Rubin Observatory—will search for unknown KBOs that lie beyond our (current) understanding.
There’s still a lot we don’t know about our Solar System, but much like our broadening view of the universe, some new facts are certainly coming into focus.
You Might Also Like
