NASA has designed a spacecraft that moves through space with a solar sail. Picture an unmanned spacecraft with a rectangular gold metallic sail that is 100 feet square. Photons from the sun moving through space hit the sail and move the spacecraft. NASA launched the NanoSail-D and deployed its sail over the U.S. in low orbit in January. Here is a link with a great picture of what the spacecraft probably looks like.
Through March 7th, the spacecraft moving through space can be seen with the naked eye (no telescope needed)! To help you see NanoSail-D, NASA has partnered with SpaceWeather.com to provide tracking maps (click here) so you know when to look up in the sky. In Chicago, we will be looking north/northwest at 6:30 pm today. SpaceWeather.com is hosting a photo competition with prizes up to $500. Go to http://www.nanosail.org/ to learn more about the contest.