The world's largest iceberg, A23a, is stuck again. For more than 30 years, the giant frozen block — equivalent to the size of Rhode Island — was grounded on the sea floor in Antarctic coastal waters.

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. For months, a ...

A cold winter is likely in store for those in the northern U.S., with milder temperatures across the southern tier, according to NOAA’s National Weather Service winter outlook issued Thursday. The ...