Astronomy Picture Of the Day (APOD)The Flight of Helios
Solar-powered, remotely piloted, and flying at about 25 miles per hour, NASA's Helios aircraft, is pictured above at 10,000 feet in skies northwest of Kauai, Hawaii on August 13. This ultralight propeller driven aircraft, essentially a flying wing with 14 electric engines, was built by AeroVironment Inc.
How Big Is 2001 KX76
Newly discovered minor planet 2001 KX76 is circled in the top panel above, a recent composite image from the European Southern Observatory's 2.2 meter telescope at La Silla, Chile. Though 2001 KX76 appears...
AFGL 2591: A Massive Star Acts Up
Young star AFGL 2591 is putting on a show. The massive star is expelling outer layers of dust-laced gas as gravity pulls inner material toward the surface. AFGL 2591 is estimated to be about...
Jagged Hills on Jupiters Callisto
Why does Jupiter's moon Callisto have unusual jagged hills? This mystery came to light after the robot spacecraft Galileo, in orbit around Jupiter since 1995, swooped past the dark moon in May. The resulting pictures were the highest resolution yet obtained for a Jovian moon: objects as small as 3 meters across are discernable.
Artificial Night Sky Brightness
Where have all the dim stars gone? From many places on the Earth including major cities, the night sky has been reduced from a fascinating display of hundreds of stars to a diffuse glow through which only a handful of stars are visible.
Uranus: The Tilted Planet
Uranus is the third largest planet in our Solar System after Jupiter and Saturn. Uranus is composed mostly of rock and ices, but with a thick hydrogen and helium atmosphere. The blue hue of Uranus' atmosphere arises from the small amount of methane which preferentially absorbs red light.
Pioneer 10: The First 7 Billion Miles
Q: What was made by humans and is 7.3 billion miles away? A: Pioneer 10 -- and 1997 was the 25th anniversary of its launch. Almost 11 light-hours distant, Pioneer 10 is presently about twice as far from the Sun as Pluto, and bound for interstellar space at 28,000 miles per hour.
NEAR at Eros: Before Touchdown
On 12 February, 2001, the NEAR-Shoemaker spacecraft gently touched-down on the the surface of Eros -- the first ever landing on an asteroid. During the descent, the spacecraft's camera recorded successive images of the diminutive world's surface, revealing fractured boulders, dust filled craters, and a mysterious collapsed channel.
Distortion from a Distant Cluster
This stunning color deep sky view toward the constellation Pisces was made with data from a fast, sensitive, digital detector known as the Big Throughput Camera operating at Cerro Tololo Inter-American Observatory in Chile.
The Bubbling Cauldron of NGC 3079
Edge-on spiral galaxy NGC 3079 is a mere 50 million light-years away toward the constellation Ursa Major. Shown in this stunning false-color Hubble Space Telescope image, the galaxy's disk - composed of spectacular star clusters in winding spiral arms and dramatic dark lanes of dust - spans some 70,000 light-years.