Try to solve this brain teaser in less than a minute.
The Moon, and the question of how it was formed, has long been a source of fascination and wonder.
Scientists are predicting a change to the night sky that will be visible to the naked eye.
Astronomers have been surprised to see a huge shadow sweeping across a disk of dust and gas encircling a nearby star, and incredibly, it takes 16 years for just one rotation.
Astronomers using NASA's Hubble Space Telescope have measured the material along the Voyager 1 and 2 probes' trajectories as they move through space.
NASA's NuSTAR (Nuclear Spectroscopic Telescope Array) recently identified two gas-enshrouded supermassive black holes, located at the centers of nearby galaxies.
"No sex allowed."
Atoms manipulated to be 4000 times larger than usual may be the tool dark-matter hunters have been waiting for.