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A thin shell of ice formed by a continuous cycle of heating and freezing gives Haumea, a distant dwarf planet discovered in 2004, its distinctive glimmer in deep space.
Astronomers knew Haumea had a frosty coating, but they didn’t know it was made of fresh, highly organized crystals instead of old, amorphous glass-like ice.
“Since solar radiation constantly destroys the crystalline structure of ice on the surface, energy sources are required to keep it organized,” said planetary scientist Benoit Carry of the European Space Agency in a press release May 12. The findings have been accepted for publication in Astronomy and Astrophysics.
Named after the Hawaiian goddess of childbirth, the rocky, football-shaped Haumea is one-tenth the size of Earth and about 43 times farther from the sun, located beyond Pluto in the Kuiper belt.
By analyzing sunlight bouncing off Haumea’s surface with the Very Large Telescope in Chile, Carry and other astronomers calculated that its surface ice is constantly replenished. They think heat from radioactive elements, combined with gravitational kneading from its two tiny satellite bodies Hi’iaka and Namaka, melts ice on Haumea’s surface. It soon refreezes, resulting in a perpetual cycle of icy renewal.
Another area of fascination for astronomers is a dark, reddish spot on Haumea’s surface. Irradiated minerals or organic matter may cause the discoloration.
Astronomer Pedro Lacerda of Queen’s University in Belfast said in the press release that it may be an especially rich source of crystalline water ice, a fountain for Haumea.
Image: Artist’s rendering of Haumea (SINC/José Antonio Peñas).
