Rings circle the solar system’s largest planets. Saturn has the most famous ring system, but Jupiter, Neptune, and Uranus are also home to rings of dust, ice, and rock.
A few years ago, scientists also discovered rings around two small bodies between Jupiter and Neptune. Today, another body gets added to the rings list. Haumea.
First discovered nearly 13 years ago, Haumea takes a long, meandering trek around the Sun. A ‘year’ on Haumea lasts 284 Earth-years. While the years are long, the days are short. Very short.
Haumea completes one rotation around its axis in just under four hours. Much quicker than any other object measuring more than a hundred kilometers long in the solar system. The fast rotation speed causes Haumea’s elongated shape. Instead of the usual circle we see from planets this size, it looks more like an egg.
“Now we have discovered that bodies even farther away than the centaurs, bigger and with very different general characteristics, can also have rings,” says Pablo Santos-Sanz, a member of the Institute of Astrophysics of Andalusia (IAA-CSIC) team responsible for this new research.
To make this discovery, scientists waited for Haumea to pass in front of a star (designated URAT1 533-182543). Twelve telescopes across ten European observatories were ready to watch the event (called an occultation) on January 21, 2017.
José Luis Ortiz, a researcher at IAA-CSIC, explains what the telescopes saw. “This deployment of technical means allowed us to reconstruct with a very high precision the shape and size of dwarf planet Haumea, and discover to our surprise that it is considerably bigger and less reflecting than was previously believed. It is also much less dense than previously thought, which answered questions that had been pending about the object.”
We now know Haumea measures 2,320 kilometers across at its widest point. About the same as Pluto. But remember, Haumea’s orbit causes it to be flattened. It’s not the same size as Pluto. Plus, Haumea doesn’t have the global atmosphere that Pluto has according to the researchers responsible for this study.
As for the ring? The researchers believe it sits 2,287 kilometers from the center of Haumea and is darker than the surface of the planet. It’s also 70 kilometers wide.
Today’s discovery shows the closer we look at these small, distant worlds, the more interesting they appear to be. Just look at Pluto. Who expected NASA’s New Horizons probe to reveal such a stunning world?
While Haumea isn’t getting an up-close visit anytime soon, another Kuiper Belt object is. New Horizons is cruising towards 2014 MU69 for a 2019 flyby. Who knows what other unique discoveries lie in the far reaches of the solar system.