Dwarf planets in our solar system: icy enigmas for stargazers

Dwarf planets are relatively new discoveries by Earth's astronomers and the term to refer to these mysterious objects beyond Neptune has only been designated in 2006 by the International Astronomical Union.

Little is known about these celestial objects floating around the Kuiper Belt. But astronomers in Europe now know for certain that at least one the dwarf planets is covered with crystalline ice.

Scientists from the European Southern Observatory (ESO) reported via a press release on Thursday that one of the dwarf planets called Haumea, a flattened body that's about 2,000 kilometers long, has been confirmed to have a crystalline ice surface rather than simple frost.

Astronomers have long theorized that Haumea is covered with ice because it shines brightly in space. What is surprising is that the ice found is crystalline or has an ordered structure, something thought to be rare for these space objects as sunlight does not allow ice to form that way.

At least 75 percent of Haumea's surface and 100 percent of its satellite Hi'iaka is covered with ice with an ordered structure because of the interplay between elements and tidal forces.

Haumea is the fifth largest of the known dwarf planets, a new classification in which Pluto was demoted as a planet by the IAU. The three other known dwarf planets are Eris, Ceres and Makemake.

Named after a Hawaiian goddess of fertility, Haumea was discovered in 2004 but there is little information yet about its orbit and structure. It has two known satellites, Hi'iaka (400 kilometers in diameter) and Namaka (200 kilometers in diameter).

The creation of the dwarf planets classification has been the subject of much debate among astronomers.