Category Archives: planetary science

And Now We Have More Naming of Dwarf Planets

Welcome to Haumea!

Haumea and its moons Hiiaka and Namaka. Artists concept by A. Feild, STScI
Haumea and its moons Hi'iaka and Namaka. Artist's concept by A. Feild, STScI

Let’s all give a big welcome to a newly named (but not newly discovered) dwarf planet orbiting the Sun out between 35 and 50 AU from the Sun. The new name is Haumea, given this week by the International Astronomical Union to honor the Hawaiian goddess of childbirth and fertility. In Hawaiian mythology, this goddess also represents the element of stone, which is very applicable to this dwarf planet. Observations of Haumea hint that this world is almost entirely composed of rock with a crust of pure ice — somewhat unusual for this region of the solar system.

Haumea is joined in its orbit by two satellites that are thought to have been created by impacts with other objects in the distant past, collisions that blasted parts of the surface away from Haumea. The debris likely re-coalesced to form the two moons. The first and largest moon is now named Hi’iaka, after the Hawaiian goddess who is said to have been born from the mouth of Haumea and the patron goddess of the island of Hawai’i. The second moon of Haumea is named Namaka, a water spirit who is said to have been born from Haumea’s body.

Rosetta and the Stone, Part II

A Diamond-shaped Asteroid

Asteroid Steins
Asteroid Steins

The European Space Agency’s Rosetta spacecraft focused its OSIRIS imaging system and the VIRTUS infrared-sensitive spectrometer on asteroid (2867 Steins) last night and came away with some great images of a diamond-shaped chunk of rock.  The images were presented at a press conference early Saturday, and they show quite a lot of detail. Rita Schulz, Rosetta Project Scientist, said, “In the images is a chain of impact craters, which must have formed from recurring impact as the asteroid rotated. The impact may have been caused by a meteoroid stream, or fragments from a shattered small body.”

That chain is made up of at least seven craters laid down when successive pieces of debris hit the asteroid. There are more images and data to analyze, making this a very well-studied asteroid indeed! You can follow the mission at the link above.