NASA is asking amateur astronomers to submit their best images of the orbiting NanoSail-D spacecraft, which belatedly and unexpectedly unfurled its 9-square-meter solar sail Jan. 20.

To encourage observations of NanoSail-D, NASA is partnering with to award a $500 grand prize for the best images. The contest, announced Jan. 26, is open to all types of images, including telescopic captures of the sail to simple wide-field camera shots of solar-sail flares.

NASA said the solar sail will be observable for 70 to 120 days before it enters the atmosphere and disintegrates.

NanoSail-D was launched in November as part of the FASTSat mission. The satellite was designed, developed and tested at the Marshall Space Flight Center in partnership with the Von Braun Center for Science & Innovation and Dynetics Inc., all of Huntsville, Ala.