Astronomy Picture Of the Day (APOD)The Sun Spews X-rays
Our Sun is really very hot. The Sun's outer atmosphere is so hot that it emits much light in the X-ray band, which was unexpected. X-rays are usually emitted from objects having a temperature in the millions of degrees, not the mere thousands of degrees of the Sun's surface.
Deimos: Small Martian Moon
Mars has two tiny moons, Phobos and Deimos. Pictured above is Deimos, the smallest moon of Mars. In fact, Deimos is the smallest known moon in the Solar System measuring only 9 miles across.
Phobos: Doomed Moon of Mars
Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These Martian moons may well...
Central Galactic Star Bursts
The pictured core of the galaxy NGC 253 shows an exceptionally high rate of star formation. In the center are some of the densest knots of stars ever found, surrounded by glowing gas and dust lanes. Galaxies where such high star formation rates are seen are called "starburst" galaxies.
An Energetic Radio Galaxy
The radio and optical emission seen in the above superposed images of the radio galaxy 3C368 indicate that energetic processes are at work. A radio galaxy is a galaxy that is visible to radio telescopes. A large radio signal usually indicates very powerful phenomena.
The International Ultraviolet Explorer
The International Ultraviolet Explorer (IUE) was launched by a NASA Delta rocket in 1978 to provide a space telescope for ultraviolet astronomy. A collaborative project among NASA, ESA and the British SRC (now PPARC) agencies, IUE's estimated lifetime was 3 to 5 years.
A Venusian Landscape
This computer generated view of a Venusian volcano was created using data from NASA's Magellan spacecraft. Magellan used its onboard radar to map the surface of Venus which is hidden from telescopic observations by a perpetual cloud cover.
A Venus Landing
This image is part of the first color panoramic view from Venus. It was transmitted by a TV camera on the Soviet Venera 13 lander which parachuted to the surface on March 1, 1982.
Star Trails in Southern Skies
As the Earth spins on its axis, the sky seems to rotate around us. This motion produces the beautiful concentric arcs traced out by the stars in this time exposure of the night sky. In the foreground of the picture is the dome of the Anglo-Australian Telescope in central New South Wales Australia.
Orion's Horsehead Nebula
The black indentation to the red emission nebula seen just to the right of center of the above photograph is one of the most famous features in any nebulae on the sky. Because of its shape, it is known as the Horsehead Nebula.