Mysterious volcanic domes - rich in silica - have been found on the far side of the moon. Their origin remains enigmatic. Read more about mystery moon domes.
On July 21, just 21 minutes before Atlantis' final deorbit burn, astrophotographer Thierry Legault captured this image of the shuttle crossing in front of the sun.
The cloud of water vapor - 140 trillion times more water than in Earth's oceans - is 12 billion light-years away and surrounds the black hole of quasar.
An exoplanet like a hot Jupiter, orbiting close to its sun, would likely have an aurora up to 1,000 times brighter than one on Earth. Read more on exoplanet aurora.
As the Hubble Space Telescope worked to support NASA's New Horizons mission to Pluto, it also found a fourth moon for the dwarf planet, scientists announced today.
NASA engineers estimate that Dawn orbit capture around Vesta took place around 5 UTC Saturday, July 16. This image is from 9,500 miles (15,000 kilometers) away.