How Big Was the Asteroid That Killed the Dinosaurs?

Encyclopædia Britannica, Inc.

Learn more about these huge solar explosions.

Encyclopædia Britannica, Inc.

Learn about phytoplankton's role as the oxygen-producing foundation of many marine food chains.

Encyclopædia Britannica, Inc.

Learn more about refraction.

JPL/NASA

Learn how scientists find and track near-Earth asteroids, which are asteroids that might pass close to Earth's orbit.

Encyclopædia Britannica, Inc.

Hell Creek was home to T. rex, Triceratops, and now…these foot bones.

Great Museums Television (A Britannica Publishing Partner)

A discussion of the competition among collectors and museums for dinosaur bones, including those of Sue, from the documentary The Dinosaur Wars.

Goddard Space Flight Center GSFC/NASA

Captured on October 20, 2020, during the OSIRIS-REx mission's Touch-and-Go (TAG) sample collection event, this series of 82 images shows the SamCam imager's field of view as the NASA spacecraft approaches and touches down on asteroid Bennu's surface. The sampling event brought the spacecraft all the way down to sample site Nightingale, and the team on Earth received confirmation of successful touchdown at 6:08 pm Eastern Daylight Time. Preliminary data show the sampling head touched Bennu's surface for approximately five seconds, after which the spacecraft performed a back-away burn.