Why Do We Have Leap Years? The Science Behind February 29
A year is not exactly 365 days. Here is why calendars add a leap day every four years, why some century years do not count and when the next leap year arrives.
Science & Space
Discoveries, space missions and environmental news from scientific agencies.
Guides & original stories
How Hurricanes Form and How They Are Rated, Explained
What a hurricane needs to form, how storms are named and rated on the Saffir-Simpson scale, why storm surge is so dangerous and how to prepare.
Latest headlines
APOD: 2026 October 14 – Mars and the Beehive Under an Aurora
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Hurricane Simon Lurks Off the Mexican Coast
Hurricane Simon, the latest in a long progression of tropical cyclones in the Eastern Pacific this season, passed close to the Mexican coast as a category 4 storm on October 11, 2026.…
NASA Names Astronaut Christina Koch Acting Deputy Chief Engineer
NASA engineer and astronaut Christina Koch will serve as the agency’s acting deputy chief engineer beginning on Sunday, Nov. 1, following the retirement of Katherine Van Hooser, who will…