By: Jacob Zari
.jpg)
A dwarf planet that sits just about 4 billion miles away from Earth, has a strange feature that leaves scientists scratching their heads.
The dwarf planet in question is named “Quaoar,” which is just about a tenth of the size of earth. The planet has a ring around it, however scientists say that the ring should not still be there.
Quaoar’s ring has a radius of about 2,420 miles, which is just too far to stay intact. The measurement that scientists use for this is called the “Roche Limit.” The Roche Limit is the line that determines if matter will stay as a ring, or break apart, sometimes in the form of a moon. In Quaoar’s case, its Roche Limit is a radius of 1,100 miles.
Dr. Monique Aller is an associate professor of Observational Astronomy at Georgia Southern. She explains that, “The authors of the Nature paper have run simulations to explore why this ring exists beyond the Classical Roche limit. Their research indicates that elastic collisions could maintain such a ring at the observed distance from the dwarf planet, particularly when combined with orbital resonances and some limitations on the properties of the ring particles.”
Dr. Aller goes on to explain that an orbital resonance “is when objects in orbit experience repeated gravitational pulls, often every integer number of orbits.”
One of the major questions that scientists are now looking into pertains to the ring’s future.
Dr. Jorge Villa-Vargas is a Lecturer in the Physics and Astronomy Department at Georgia Southern, and he mentions that, “Models predict that a ring like the one discovered around Quaoar should start assembling into a moon in only a few decades. For this reason it is very improbable that the fragments of the ring are the result of a recently destroyed moon, and that we have discovered it at the right time,” says Villa-Vargas.
Dr. Aller has a similar idea when it comes to the ring. She says that “Models indicate small particles in the ring likely have a short lifetime, perhaps a few decades or less, depending on their sizes. Larger particles, however, may last for much longer. For comparison, Saturn’s rings likely formed 10-100 million years ago.”
For others, this type of discovery raises red flags. Dr. Clayton Heller is the director of the Planetarium at Georgia Southern, and he voiced his concerns about the recent discovery.
“So you are telling me that they were able to see a thin ring like that, all the way out in the Kuiper Belt? I haven’t seen much on this planet so far, but from what I have seen, I have not noticed an actual ring,” Heller said.
This ring may not have a direct impact on Earth, but scientists say that this is a good stepping stone for future research.
“Understanding the dynamics of systems like Quaoar can help to better understand how the objects of the solar system, including our planet, got assembled and evolved,” says Villa-Vargas.
Dr. Aller adds that “it is of interest to astronomers to better understand how and where material can form into rings (or conversely accrete into larger objects).”