The dwarf planet Quaoar has a ring that is too big for its metaphorical fingers. While all other rings in the solar system lie within or near a mathematically determined distance of their parent bodies, Quaoar’s ring is much farther out.
“For Quaoar, for the ring to be outside this limit is very, very strange,” says astronomer Bruno Morgado of the Federal University of Rio de Janeiro. The finding may force a rethink of the rules governing planetary rings, Morgado and colleagues say in a study published February 8 in Nature.
Quaoar is an icy body about half the size of Pluto that’s located in the Kuiper Belt at the solar system’s edge (SN: 8/23/22). At such a great distance from Earth, it’s hard to get a clear picture of the world.
So Morgado and colleagues watched Quaoar block the light from a distant star, a phenomenon called a stellar occultation. The timing of the star winking in and out of view can reveal details about Quaoar, like its size and whether it has an atmosphere.
The researchers took data from occultations from 2018 to 2020, observed from all over the world, including Namibia, Australia and Grenada, as well as space. There was no sign that Quaoar had an atmosphere. But surprisingly, there was a ring. The finding makes Quaoar just the third dwarf planet or asteroid in the solar system known to have a ring, after the asteroid Chariklo and the dwarf planet Haumea (SN: 3/26/14; SN: 10/11/17).
2023-02-08 11:00:00
Source from www.sciencenews.org
The Solar System is an incredible place, from its planets and moons to the mysterious and fascinating objects found beyond the outer planets. Recently, scientists have uncovered a most incredible and unexpected feature of a small world in the Kuiper Belt: Quaoar, a dwarf planet, has an impossible ring.
Quaoar is located in the outer reaches of the Solar System, beyond Neptune, in a second belt of icy objects known as the Kuiper Belt. It orbits the Sun almost nine billion miles away and is only about 690 miles across — less than one-seventh the size of Earth’s Moon.
Recently, an international team of scientists used the Hubble Space Telescope to study Quaoar and were surprised to discover an unexpected feature: a seemingly impossible ring. The ring of icy particles is an additional 17,550 miles above Quaoar’s surface — farther than the distance between Earth and the Moon!
The ring should not exist. According to current theories, the gravity of small, icy objects like Quaoar cannot keep a ring in place. Scientists believe the ring of icy particles must be continually resupplied, otherwise it could not remain in orbit for more then a few million years. That’s because the particles are too small and light to be held in place by the planet’s gravity.
How the ring was created and how it continues to exist remain a mystery. It may have been created from a relatively recent collision with a comet or it could be the result of material being flung off the planet’s surface due to its rapid rotation. More observations are required to determine the exact cause of the ring.
In conclusion, Quaoar’s impossible ring challenges current theories of orbital dynamics, challenging scientists to come up with creative ideas to explain this strange and amazing feature in the distant reaches of the Solar System.