  We report the detection of crystalline water ice on the surface of 2003 EL61.
Reflectance spectra were collected from Gemini North telescope from 1.0 to 2.4
micron wavelength range, and from the Keck telescope across the 1.4 to 2.4
micron wavelength range. The signature of crystalline water ice is obvious in
all data collected. Like the surfaces of many outer solar system bodies, the
surface of 2003 EL61 is rich in crystalline water ice, which is energetically
less favored than amorphous water ice at low temperatures, suggesting that
resurfacing processes may be taking place. The near infrared color of the
object is much bluer than a pure water ice model. Adding a near infrared blue
component such as hydrogen cyanide or phyllosilicate clays improves the fit
considerably, with hydrogen cyanide providing the greatest improvement. The
addition of hydrated tholins and bitumens also improves the fit but is
inconsistent with the neutral V-J reflectance of 2003 EL61. A small decrease in
reflectance beyond 2.3 micron may be attributable to cyanide salts. Overall,
the reflected light from 2003 EL61 is best fit by a model of 2/3 to 4/5 pure
crystalline water ice and 1/3 to 1/5 near infrared blue component such as
hydrogen cyanide or kaolinite. The surface of 2003 EL61 is unlikely to be
covered by significant amounts of dark material such as carbon black, as our
pure ice models reproduce published albedo estimates derived from the spin
state of 2003 EL61.
