David Jewitt (University of Hawaii) and Jane Luu (MIT Lincoln Lab) have obtained the first high quality spectrum of Quaoar using the Subaru telescope.

Quaoar is a bright object in the Kuiper Belt, the repository of the Solar System's most primitive building blocks beyond the orbit of the planet Neptune. The spectrum shows evidence for crystalline water ice which has an approximate lifetime of 10 million years on Quaoar's surface. This suggests that some process is still active, 4500 million years after the formation of the Solar System, either excavating Quaoar's surface to reveal crystalline water ice formed in the past, or heating it to create new crystalline water ice.

While the interpretation remains speculative, the good news is that astronomers are, for the first time, able to take useful spectra that reveal unexpected and intriguing properties of the surface of distant Quaoar.

Link

More info: Subaru telescope web page