Lunation
7.11.1999

Our Moon's appearance changes nightly. This slow-loading time-lapse sequence shows what our Moon looks like during a lunation, a complete lunar cycle. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible. The Moon always keeps the same face toward the Earth.

Return at Sunrise
13.03.2015

Thursday, shortly after local sunrise over central Asia, this Soyuz spacecraft floated over a sea of golden clouds during its descent by parachute through planet Earth's dense atmosphere. On board were Expedition 42 commander Barry Wilmore of NASA and Alexander Samokutyaev and Elena Serova of the Russian Federal Space Agency (Roscosmos).

Earth During a Total Eclipse of the Sun
17.03.2015

What does the Earth look like during a total solar eclipse? It appears dark in the region where people see the eclipse, because that's where the shadow of the Moon falls. The shadow...

Ganymede: The Largest Moon in the Solar System
20.06.2000

If Ganymede orbited the Sun, it would be considered a planet. The reason is that Jupiter's moon Ganymede is not only the largest moon in the Solar System, it is larger than planets Mercury and Pluto.

Neighboring Galaxy: The Large Magellanic Cloud
4.08.2001

The brightest galaxy visible from our own Milky Way Galaxy is the Large Magellanic Cloud (LMC). Visible predominantly from Earth's Southern Hemisphere, the LMC is the second closest galaxy, neighbor to the Small Magellanic Cloud, and one of eleven known dwarf galaxies that orbit our Milky Way Galaxy.

M1: The Exploding Crab Nebula
21.11.1995

The Crab Nebula resulted from a star that exploded - a supernova. The outer layers of the star were thrown violently into space, while the inner core collapsed to form a neutron star. This neutron...

A Crescent Earth At Midnight
6.10.1996

The Earth's northern hemisphere appears outlined as a sunlit crescent in this dramatic view from the GOES 8 satellite. The image was made near midnight for the Geostationary Operational Environmental Satellite on June 22 this year, two days after the Summer Solstice.

WR124: Stellar Fireball
8.11.1998

Some stars explode in slow motion. Rare, massive Wolf-Rayet stars are so tumultuous and hot they are disintegrating right before our telescopes. Glowing gas globs each over 30 times more massive than the Earth are being expelled by a violent stellar wind.

Neighboring Galaxy: The Large Magellanic Cloud
21.02.2000

The brightest galaxy visible from our own Milky Way Galaxy is the Large Magellanic Cloud (LMC). Visible predominantly from Earth's Southern Hemisphere, the LMC is the second closest galaxy, neighbor to the Small Magellanic Cloud, and one of eleven known dwarf galaxies that orbit our Milky Way Galaxy.

Oklo: Ancient African Nuclear Reactors
12.09.2010

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.