Learn about the comet impact hypothesis that may explain why North America lost most of its megafauna along with the Clovis ...

Meteorological seasons are defined by the weather. They break down the year into three-month seasons based on annual ...

On Monday, Sept. 22, day and night will be nearly equal in length as Earth's axis is side-on to the sun, officially beginning ...

September is the Autumnal Equinox — the beginning of fall — in the Northern Hemisphere. Here’s a look at “What’s up in the sky” in the D.C. region this month.