  We have obtained a near infrared spectrum of the brightest satellite of the
large Kuiper Belt Object, 2003 EL61. The spectrum has absorption features at
1.5 and 2.0 microns, indicating that water ice is present on the surface. We
find that the satellite's absorption lines are much deeper than water ice
features typically found on Kuiper Belt Objects. We argue that the unusual
spectrum indicates that the satellite was likely formed by impact and not by
capture.
