Neil Armstrong Takes Humankind's First Steps on the Lunar Surface During NASA's Apollo 11 Mission

Contunico © ZDF Studios GmbH, Mainz

Overview of various Pacific coral reef sharks, notably the blacktip reef shark, gray reef shark, and nurse shark.

Encyclopædia Britannica, Inc.

Video showing how roots take up substances from the soil via osmosis, diffusion, and active transport.

Encyclopædia Britannica, Inc.

All wild axolotls live in the same small lake, and some of the qualities of this unique ecological context have allowed them to remain in their juvenile stage throughout their lives.

Media Editor: Lee Goldstein

NASA

This video shows an Apollo mission taking off from the Moon. The Lunar Module consisted of two parts. The lower half, or descent stage, contained the landing engine and gear and was left behind to save weight and fuel. The upper half, or ascent stage, carried the astronauts to a rendezvous with the orbiting Command and Service modules, which took them back to Earth. The liftoff was recorded with a camera on the mission's Lunar Roving Vehicle.

© Open University (A Britannica Publishing Partner)

A discussion of the Nice model (named for Nice, France) of the formation of the orbital structure of the outer planets and the Kuiper belt. The Nice model also accounts for the age of some Moon rocks.

NASA/Dryden Research Aircraft Movie Collection

At NASA's Dryden Flight Research Center in California, test flights of the X-15 rocket-powered airplane, the M2-F1 “lifting body” reentry vehicle, and the LLRV (Lunar Landing Research Vehicle) during the 1960s contributed vital information to the U.S. space program.

Encyclopædia Britannica, Inc.

History of the American human spaceflight program in the 1960s.