The Soviet Union was the world's first communist country and had a major influence on the 20th century — and still has an influence today.
Astronomers may have discovered a binary pair of supermassive black holes that are doomed to collide 10,000 years from now.
A mountain-sized chunk of volcanic rock under Japan is changing the way that tectonic plates subduct and may be channeling the direction of earthquakes.
Stonehenge may have been used as a solar calendar, with each of the stones representing a day and sections of the circle of stones possibly corresponding to weeks.