Chandras First Light: Cassiopeia A
27.08.1999

Cosmic wreckage from the detonation of a massive star is the subject of this official first image from NASA's Chandra X-ray Observatory. The supernova remnant, known as Cassiopeia A, was produced when a star exploded around 300 years ago in this northern sky constellation.

Southern Neptune
10.07.1999

Neptune, the Solar System's outermost gas giant planet, is 30 times farther from the Sun than Earth. Twelve years after a 1977 launch, Voyager 2 flew by Neptune and found surprising activity on a planet that receives only 3 percent as much sunlight as Jupiter.

In the Heart of the Virgo Cluster
8.07.2008

The Virgo Cluster of Galaxies is the closest cluster of galaxies to our Milky Way Galaxy. The Virgo Cluster is so close that it spans more than 5 degrees on the sky - about 10 times the angle made by a full Moon.

Titan, Rings, and Saturn from Cassini
7.03.2011

How thin are the rings of Saturn? Saturn's rings to be about one kilometer thick, making them many times thinner, in relative proportion, than a razor blade. This thinness sometimes appears in dramatic fashion during an image taken nearly along the ring plane.

Echoes from the Depths of a Red Giant Star
8.04.2011

A journey to the center of a red giant star is very firmly in the realm of science fiction. But the science of asteroseismology can explore the conditions there. The technique is to time the small variations in a star's brightness measured by the planet hunting Kepler spacecraft.

Red Aurora Over Australia
1.02.2012

Why would the sky glow red? Aurora. Last week's solar storms, emanating mostly from active sunspot region 1402, showered particles on the Earth that excited oxygen atoms high in the Earth's atmosphere. As the excited element's electrons fell back to their ground state, they emitted a red glow.

Dark Sand Cascades on Mars
25.11.2012

They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars.

Filaments of the Vela Supernova Remnant
1.10.2013

The explosion is over but the consequences continue. About eleven thousand years ago a star in the constellation of Vela could be seen to explode, creating a strange point of light briefly visible to humans living near the beginning of recorded history.

Cataclysmic Dawn
10.01.2015

Will this dawn bring another nova? Such dilemmas might be pondered one day by future humans living on a planet orbiting a cataclysmic variable binary star system. Cataclysmic variables involve gas falling from a large star onto an accretion disk surrounding a massive but compact white dwarf star.

Pluto Resolved
14.07.2015

New Horizons has survived its close encounter with Pluto and has resumed sending back images and data. The robotic spacecraft reported back on time, with all systems working, and with the expected volume of data stored.