Stars are giant, luminous spheres of plasma. Galaxies consist of stars, stellar remnants, dust, gas, and dark matter, bound together by gravity. Learn more about stars and galaxies.
This fascinating Chandra X-Ray Observatory space wallpaper of the young star cluster NGC 346 highlights a heart-shaped cloud of 8 million-degree Celsius gas in the central region.
This stunning space wallpaper is the first map of radioactivity in a supernova remnant, the blown-out bits and pieces of a massive star that exploded.
NASA's Cold Atom Laboratory utilizes a magnetic trap that confines particles, allowing them to cool to temperatures just barely above absolute zero as seen in this space wallpaper.
This space wallpaper shows Jupiter's moon Ganymede centered at 200 west longitude. This mosaic (right) served as the base map for the geologic map of Ganymede (left).
This stunning space wallpaper is a composite of 25 separate images spanning the period of Feb. 11, 2013 to Feb. 11, 2014.
This space wallpaper is an artist's impression based on the first ever map of the weather on the surface of the nearest brown dwarf to Earth.
The left-front wheel of NASA's Curiosity Mars rover shows dents and holes in this cool space wallpaper taken during the 469th Martian day, or sol, of the rover's work on Mars (Nov. 30, 2013).