Astronomy Picture Of the Day (APOD)A Supernova Starfield
Bright stars don't last forever. A bright star similar to others in this field exploded in a spectacular supernova that was witnessed on Earth in 1987. The result is visible even today as unusual rings and glowing gas. The above picture is a composite of recent images taken over several years.
The Solar Wind Emerges
Winds of fast particles blow out from the Sun, but why? Astronomers came a step closer to answering this question recently by making detailed observations of the high-speed wind source with the space-borne Solar and Heliospheric Observatory (SOHO).
Titan: Saturns Smog Moon
The largest moon of Saturn is a rare wonder. Titan is the only one of Saturn's moons with an atmosphere, and one of only two moons in the Solar System with this distinction (Neptune's Triton is the other).
The First Explorer
The first US spacecraft was Explorer 1. The cylindrical 30 pound satellite was launched (above) as the fourth stage of a Jupiter-C rocket (a modified US Army Redstone ballistic missile) and achieved orbit on January 31, 1958.
HR 4796A: Not Saturn
These are not false-color renderings of the latest observations of Saturn's magnificent rings. Instead, the panels show a strikingly similar system on a much larger scale - a ring around the young, Vega-like star, HR 4796A, located about 200 light-years from Earth.
Spiral galaxies abound in the universe, but spiral sunspots are definitely an unusual twist. This distinctive spiral-shaped sunspot caught the attention of National Solar Observatory astronomers and was photographed on February 19, 1982 with the Vacuum Solar Telescope on Kitt Peak.
A Galactic Mushroom Cloud
Part of our Galaxy is exploding. Recent radio observations show new details of hot gas expanding rapidly from an energetic star-forming region in our Galactic disk out into our Galaxy's halo. The combined power of at least hundreds of supernovae is needed to drive this tremendous expansion.
The Orion Nebula from Subaru
The Orion Nebula (M42) shows a host of treasures when viewed in infrared light. Some stars in the Trapezium, an open cluster of stars at the center, are only visible in infrared light. The orange feature above center is called the Kleinman-Low Nebula, and appears greatly affected by newly forming central star IRc2.
The Subaru Telescope
Last week, Japan's new Subaru Telescope made its first observations of the sky. The gray building housing Subaru is visible just left of the white Keck domes near the photo's center. Subaru is the latest in the class of optical telescopes using a mirror with a diameter greater than 8 meters.
Welcome to Planet Earth
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.