Astronomy Picture Of the Day (APOD)The Very Large Array Turns Twenty
The most photogenic array of radio telescopes in the world has also been one of the most productive. Each of the 27 radio telescopes in the Very Large Array (VLA) is the size of a house and can be moved on train tracks.
Olympus Mons Volcano on Mars
Scroll right to virtually climb the largest volcano in the Solar System. Olympus Mons on Mars measures three times higher than Earth's highest mountain, and has a volume over fifty times greater than Earth's largest volcano. The caldera at the top is over 70 kilometers wide.
Skylab Over Earth
Skylab was an orbiting laboratory launched by a Saturn V rocket in May 1973. Skylab was visited three times by NASA astronauts who sometimes stayed as long as two and a half months. Many scientific tests were performed on Skylab, including astronomical observations in ultraviolet and X-ray light.
M51: The Center Of The Whirlpool
In the center of M51, a spiral galaxy 23 million light-years away, astronomers have identified a dense region of young stars. Viewed face-on in the constellation Canes Venatici, the swirling arcs of this galaxy's spiral arms have inspired its popular name, The Whirlpool Galaxy.
Nearly 400 years ago astronomer Johannes Kepler observed comet tails blown by a solar breeze and suggested that vessels might likewise navigate through space using appropriately fashioned sails. It is now widely recognized that...
Eros Horizon View
Since April 30, the robotic NEAR-Shoemaker spacecraft has been orbiting only 31 miles from asteroid Eros. Cruising over the asteroid's north and south poles at a leisurely 7 miles per hour, the spacecraft completes an orbit once every 1.2 earth days. This dramatic horizon view
Pleiades, Planets, And Hot Plasma
Bright stars of the Pleiades, four planets, and erupting solar plasma are all captured in this spectacular image from the space-based SOlar and Heliospheric Observatory (SOHO). In the foreground of the 15 degree wide field of view, a bubble of hot plasma, called a Coronal Mass Ejection (CME)
M4: The Closest Known Globular Cluster
M4 is a globular cluster visible in dark skies about one degree west of the bright star Antares in the constellation Scorpius. M4 is perhaps the closest globular cluster at 7000 light years, meaning that we see M4 only as it was 7000 years ago, near the dawn of recorded human history.
Light Bridges on the Sun
Bridges the length of a planet can form on the Sun in a matter of hours. Known as light bridges, these structures may form as large sunspot groups decay. Above, one of the sharpest photographs of the Sun ever taken shows two such light bridges that appeared late last month.
Antares and Rho Ophiuchi
Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark.