Astronomy Picture of the Day . ... Orcus of the Outer Solar System . ... 90482 Orcus was first discovered in 2004 and is slightly smaller than Pluto, although still one of the largest Kuiper belt objects known. ... Martian Dunes and the Shadow of Opportunity . ... To others it may look like a grazing seahorse, but the dark object toward the image right is actually an inanimate pillar of smoky dust about 20 light years long. ... Equinox means equal night. ... First page ] Prev. ...