Oklo: Ancient African Nuclear Reactors
16.10.2002

The remnants of nuclear reactors nearly two billion years old were found in the 1970s in Africa. These reactors are thought to have occurred naturally. No natural reactors exist today, as the relative density of fissionable uranium has now decayed below that needed for a sustainable reaction.

Apollo 17 Panorama: Astronaut Running
10.12.2006

What would it be like to explore the surface of another world? In 1972 during the Apollo 17 mission, astronaut Harrison Schmitt found out first hand. In this case, the world was Earth's own Moon.

Twilight in a Flower
6.05.2023

Transformed into the petals of a flower, 16 exposures show the passage of day into night in this creative timelapse skyscape. Start at the top and move counterclockwise to follow consecutive moments as the twilight sky turns an ever darker blue and night blossoms.

Welcome to Planet Earth
26.10.1997

Welcome to Planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen.

Jupiter's Rings
2.08.1995

Astronomers using NASA's Voyager spacecraft to search for a ring system around Jupiter discovered these faint rings in 1979. Unlike Saturn's bright rings which are composed of chunks of rock and ice, Jupiter's rings appear to consist of fine particles of dust.

Apollo 11: Catching Some Sun
20.09.2003

Bright sunlight glints and long dark shadows dramatize this image of the lunar surface taken by Apollo 11 astronaut Neil Armstrong, the first to walk on the Moon. Pictured is the mission's lunar...

Mimas: Small Moon with a Big Crater
25.04.1999

Mimas is one of the smaller moons of Saturn but shows one of the largest impact craters. In fact, if the impact had been much greater, it would have disrupted the entire satellite. The large crater has been named Herschel after the 1789 discoverer of Mimas, Sir William Herschel.

Oklo: Ancient African Nuclear Reactors
20.02.2005

The remnants of nuclear reactors nearly two billion years old were found in the 1970s in Africa. These reactors are thought to have occurred naturally. No natural reactors exist today, as the relative density of fissile uranium has now decayed below that needed for a sustainable reaction.

Stonehenge: Ancient Monument to the Sun
12.09.1999

Stonehenge consists of large carved stones assembled about 4000 years ago. Long before modern England was established, ancient inhabitants somehow moved 25 ton rocks nearly 20 miles to complete it. From similar constructs...

Mimas: Small Moon with A Big Crater
24.09.1995

Mimas is one of the smaller moons of Saturn but shows one of the largest impact craters! In fact, if the impact had been much greater, it would have disrupted the entire satellite. The large crater has been named Herschel after the 1789 discoverer of Mimas, Sir William Herschel.