Since its launch two years ago, the Chandra X-Ray telescope has captured some of the most beautiful and haunting images of the deep universe.
Now, a gallery of the best pictures from the last two years is available online.
Astronomers at Harvard University have gathered nearly 50 of Chandra's most stunning images into a series of desktop wallpapers, screensavers and virtual post cards.
The awe-inspiring pictures show a range of exotic cosmic phenomena such as pulsars, supernovae and giant dust clouds being sucked into super-massive black holes.
Sitting in high orbit above the Earth, the Chandra observatory was the third of NASA's "great observatories," orbiting telescopes that include the Hubble and the now-defunct Compton Gamma-ray Observatory.
Named after the late Subrahmanyan Chandrasekhar, one of the greatest astrophysicists of the twentieth century, the Chandra X-Ray telescope peers deep into the universe.
It has captured images of gas clouds so vast that light takes more than five-million years to go from one end to the other. And it's a great time machine, observing galaxies as they appeared 12 billion years ago.
And although nothing can escape a black hole, not even light, the Chandra telescope can capture images of particles in the last millisecond before they are sucked inside.
-- By Leander Kahney.
