What's the story behind mysterious "halos" of bare sand that surround coral reefs? When reefs are healthy an unusual phenomenon occurs: a perimeter of bare sand forms around the corals. These ...

Coral reef halos, also known as grazing halos or sand halos, are bands of bare, sandy seafloor that surround coral patch reefs. These features, clearly-visible from satellite imagery, may provide a ...

For the first time in almost 5,000 years of observations, researchers have fully cataloged optical illusions created in the sky as light shines through ice crystals known as atmospheric halos. The ...

Every galaxy is thought to form at the center of a dark matter halo. Stars are formed when gravity within dark matter halos draws in gas, but astrophysicists don't know whether star-free dark matter ...

PITTSBURGH (KDKA) -- When you hear the word halo, you may think of an angel. The topic here is halos, but these ones are in the sky, and something I get asked about a lot. They are sun halos, or the ...