NASA: Hydra, Pluto's Moon Wrapped in 'Pristine' Ice Water
NASA's New Horizon mission was launched in 2006. It was the first mission Pluto's icy system. The New Horizon spacecraft have sent data about Pluto's satellites including Hydra, one of Pluto's smallest and farthest moon. According to the data, it was distinctively proven that Hydra is wrapped in 'nearly pristine water ice.'
Hydra was discovered in 2005 but due to their immense distance to Earth, very little information is available about the moon. The findings coincides with the older studies which stated that Hydra have a reflective surface. Now the latest data explains why. In the latest report by NASA, the recently beamed information known as infrared spectra "show the unmistakable signature of crystalline water ice: a broad absorption from 1.50 to 1.60 microns and a narrower water-ice spectral feature at 1.65 microns." The data was gathered by Ralph/Linear Etalon Imaging Spectral Array (LEISA) instrument.
There's a similarity in composition between Pluto's larger moon, Charon, which also contained water ice. But recent finding shows that the grains of ice on Hydra's surface are larger and more reflective on some angles as compared to Charon. "Hydra's deep water bands and high reflectance imply relatively little contamination by darker material that has accumulated on Charon's surface over time" said NASA.
In another NASA report, they describe Hydra's properties. It is an irregular-shaped moon which measures 34 miles 955 kilometers) in length.
Older study suggests that Hydra and Charon might have been joined together in the past. But the question is why they exhibit different icy behavior. "Perhaps micrometeorite impacts continually refresh the surface of Hydra by blasting off contaminants," said Simon Porter, New Horizons science team member from Southwest Research Institute in Boulder, Colorado.
The New Horizon is working to obtain more information about other moons from Pluto so they can compare their compositions and bevahoirs with Hydra and Charon.