Astronomy Picture Of the Day (APOD)Pluto: The Frozen Planet
This portrait of Pluto and its companion Charon was taken by the Hubble Space Telescope in 1994. Pluto is usually the most distant planet from the Sun but because of its eccentric orbit Pluto crossed inside of Neptune's orbit in 1979.
Lunar Close Up
Late last month, NASA's Lunar Prospector spacecraft moved in for a closer look at the Moon. Now entering an extended mission phase, controllers have reduced the altitude of this polar lunar orbiter from 100 kilometers to about 30 kilometers (18 miles).
A Disk and Jet in Haro 6-5B
Planets condense from disks. Several new Hubble Space Telescope pictures of stars surrounded by disks were released earlier this week. Since the glare of the central star usually makes a surrounding disk hard...
GRB 990123 Host Galaxy Imaged
Do the powerful explosions known as gamma-ray bursts (GRBs) originate in galaxies? This subject took on new light yesterday with the release of a Hubble Space Telescope image of the sky surrounding GRB 990123. This burst was first detected only two weeks ago and cataloged as one of the most powerful GRBs ever.
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.