Ganymede Enhanced: What does the largest moon in the Solar System look like? Ganymede, larger than even Mercury and Pluto, has a surface speckled with bright young craters overlying a mixture of older, darker, more cratered terrain laced with grooves and ridges. Like Earth's Moon, Ganymede keeps the same face towards its central planet, in this case Jupiter.
Orion A colony of hot, young stars lives in the Orion nebula, about 1,450-light years from Earth. This image was captured shortly after Spitzer's warm mission phase began. Image and caption: NASA/JPL-Caltech/J. Stauffer (SSC/Caltech)