The International Space Station Expands Again
23.06.2008

The developing International Space Station (ISS) has changed its appearance again. Earlier this month, the Space Shuttle orbiter Discovery visited the ISS and added components that included Japan's Kibo Science Laboratory. The entire...

Phases of the Moon
10.03.2018

Look at the Moon every night and its visible sunlit portion gradually changes. In phases progressing from New Moon to Full Moon to New Moon again, a lunar cycle or lunation is completed in about 29.5 days.

Steep Cliffs on Mars
15.03.2005

Vertical cliffs of nearly two kilometers occur near the North Pole of Mars. Also visible in the above image of the Martian North Polar Cap are red areas of rock and sand, white areas of ice, and dark areas of unknown composition but hypothesized to be volcanic ash.

Steep Cliffs on Mars
1.07.2007

Vertical cliffs of nearly two kilometers occur near the North Pole of Mars. Also visible in the above image of the Martian North Polar Cap are red areas of rock and sand, white areas of ice, and dark areas of unknown composition but hypothesized to be volcanic ash.

A Zodiacal Skyscape
23.02.2012

Venus and Jupiter are this month's two brightest planets. Shortly after sunset on February 20, they dominate the sky above the western horizon and this snowy landscape. In clear and transparent skies over Cherry Springs State Park, Pennsylvania, USA, they are also seen immersed in Zodiacal light.

Comet Garradd and M92
4.02.2012

Sweeping slowly through the constellation Hercules, Comet Garradd (C2009/P1) passed with about 0.5 degrees of globular star cluster M92 on February 3. Captured here in its latest Messier moment, the steady performer remains just below naked-eye visibility with a central coma comparable in brightness to the dense, well-known star cluster.

Auroras Over Both Earth Poles
14.11.2001

Auroras in the north and south can be nearly mirror images of each other. Such mirroring had been suspected for centuries but dramatically confirmed only last month by detailed images from NASA's orbiting Polar spacecraft.

Astronaut at Work
30.05.2004

Did you ever have a day where everything got turned around and you just couldn't tell which way was up? Fortunately, this didn't happen to astronaut James S. Voss on 2000 May 21, who spent six hours preparing to fix and upgrade the International Space Station.

Southern Jupiter from Perijove 3
17.12.2016

Southern Jupiter looms some 37,000 kilometers away in this JunoCam image from December 11. The image data was captured near Juno's third perijove or closest approach to Jupiter, the spacecraft still in its 53 day long looping orbit.

Mercury on the Horizon
20.03.2000

Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it is never seen far from the Sun, and so is only visible near sunrise or sunset. If trailing the Sun, Mercury will be visible for several minutes before it follows the Sun behind the Earth.