Astronomy Picture Of the Day (APOD)Scorpius in Red and Blue
Cosmic dust clouds dim the light of background stars. But they also reflect the light of stars nearby. Since bright stars tend to radiate strongly in the blue portion of the visible spectrum, and the interstellar dust scatters blue light more strongly than red, the dusty reflection nebulae tend to be blue.
All the Water on Europa
How much of Jupiter's moon Europa is made of water? A lot, actually. Based on the Galileo probe data acquired during its exploration of the Jovian system from 1995 to 2003, Europa posses a deep, global ocean of liquid water beneath a layer of surface ice.
A Partial Solar Eclipse over Texas
It was a typical Texas sunset except that most of the Sun was missing. The location of the missing piece of the Sun was not a mystery -- it was behind the Moon. Sunday night's partial eclipse of the Sun by the Moon turned into one of the best photographed astronomical events in history.
A Close Pass of Saturns Moon Dione
What's that past Dione? When making its closest pass yet of Saturn's moon Dione late last year, the robotic Cassini spacecraft snapped this far-ranging picture featuring Dione, Saturn's rings, and the two small moons Epimetheus and Prometheus.
A Partial Eclipse Over Manila Bay
What's happened to the setting Sun? An eclipse! In early 2009, the Moon eclipsed part of the Sun as visible from parts of Africa, Australia, and Asia. In particular the above image, taken from the Mall of Asia seawall, caught a partially eclipsed Sun setting over Manila Bay in the Philippines.
Annular Solar Eclipse
Tomorrow, May 20, the Moon's shadow will race across planet Earth. Observers within the 240-300 kilometer wide shadow track will be able to witness an annular solar eclipse as the Moon's apparent size is presently too small to completely cover the Sun.
GALEX: The Andromeda Galaxy
A mere 2.5 million light-years away, the Andromeda Galaxy really is just next door as large galaxy's go. So close, and spanning some 260,000 light-years, it took 11 different image fields from the Galaxy Evolution Explorer (GALEX) satellite's telescope to produce this gorgeous portrait of the spiral galaxy in ultraviolet light.
Herschel s Cygnus X
The Herschel Space Observatory's infrared view of Cygnus X spans some 6x2 degrees across one of the closest, massive star forming regions in the plane of our Milky Way galaxy. In fact, the rich stellar nursery already holds the massive star cluster known as the Cygnus OB2 association.
Star Formation in the Tarantula Nebula
The largest, most violent star forming region known in the whole Local Group of galaxies lies in our neighboring galaxy the Large Magellanic Cloud (LMC). Were the Tarantula Nebula at the distance of the Orion Nebula -- a local star forming region -- it would take up fully half the sky.
All the Water on Planet Earth
How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius.