Researchers discover the fourth dwarf planet with ring
Oct 12 2017 by Marjorie Miles
Both those worlds are on the smaller end of the dwarf planet spectrum.
Haumea's ring has a radius of almost 1,500 miles, the team discovered, and it moves very slowly in contrast with its host planet.
Of course, rings around larger worlds in the Solar System are common, and while Saturn's is the most famous and extensive, there are also ring systems around the other giant planets: Jupiter, Uranus, and Neptune.
Pluto, Eris, Makemake and Haumea are particularly hard to study due to their small size, low brightness, and enormous distance.
In fact, all of its strangeness might be linked with Haumea and its two moons - Hi'aka and Namaka - potentially originating from a larger Haumea that was struck by something in the Kuiper Belt. An entire day on the dwarf planet lasts only four hours.
They say the dwarf planet has an unusual elongated ellipsoid shape, with axes of approximately 2,322 kilometres (1,442 miles) by 1,704 kilometres (1,059 miles) by 1,138 kilometres (707 miles), and no global atmosphere that can be detected.
The discoverer of six moons and three planetary rings-including the gossamer rings of Jupiter-Mark Showalter is now heading up the hazard planning team for New Horizon's next flyby target, a tiny object in the Kuiper belt known as MU69.
But Haumea's ring is the first time astronomers have witnessed the phenomenon in a minor planet that isn't a Centaur.
The nomenclature of dwarf came into existence when thousands of Neptunian objects located in the outer solar system were found to be approximately the size of the Pluto which led the International Astronomical Union to create the category of dwarf planets.
Haumea is one of the fastest objects when talking about the speed any planet takes to rotate. The new information could cost Haumea its dwarf planet status. They got 10 Earth-based observatories ready, and on that night all pointed their telescopes towards the same patch of sky to learn as much as they could.
The paper also suggests that Haumea might not be as small as we think.
As for whether the finding at Haumea means MU69 could have New Horizons-smashing rings of its own, Ortiz says he doubts it. But as for how it formed, we don't yet know. Ortiz estimates that about a quarter of bodies in the outer solar system might have rings around them, although he stresses that this is still "pure speculation" for now.