Astronomy Picture of the Day

2010-02-05 Jean-Luc Dauvergne

It's spring for the northern hemisphere of Mars and spring on Mars usually means dust storms. So the dramatic brown swath of dust (top) marking the otherwise white north polar cap in this picture of the Red Planet is not really surprising. Taking ...

2010-02-04 Máximo Ruiz

This cosmic expanse of dust, gas, and stars covers close to 3 degrees on the sky in the heroic constellation Perseus. Right of center in the gorgeous skyscape is the dusty blue reflection nebula NGC 1333, about 1,000 light-years away. At that ...

2010-02-03

What is this strange object? First discovered on ground based LINEAR images on January 6, the object appeared unusual enough to investigate further with the Hubble Space Telescope last week. Pictured above, what Hubble saw indicates that P/2010 ...

2010-02-02 Wally Pacholka

ven from the top of a volcanic crater, this vista was unusual. For one reason, Mars was dazzlingly bright two weeks ago, when this picture was taken, as it was nearing its brightest time of the entire year. Mars, on the far upper left, is the ...

2010-02-01

Another moon of Saturn has been imaged in detail by the Cassini spacecraft. Orbiting Saturn since 2004, the robotic Cassini got its closest look yet at Saturn's small moon Prometheus last week. Visible above in an unprocessed image from 36,000 ...

2010-01-31

The ancient text has no known title, no known author, and is written in no known language: what does it say and why does it have many astronomy illustrations? The mysterious book was once bought by an emperor, forgotten on a library shelf, sold ...

2010-01-30 Adam Block

Charles Messier described the 88th entry in his 18th century catalog of Nebulae and Star Clusters as a spiral nebula without stars. Of course the gorgeous M88 is now understood to be a galaxy full of stars, gas, and dust, not unlike our own Milky ...

2010-01-29 Alan Friedman

Mars is at opposition tonight, opposite the Sun in planet Earth's sky. Of course, it will be easy to spot because Mars appears close to tonight's Full Moon, also opposite the Sun in Earth's night sky in the constellation Cancer. For this ...

2010-01-28 Noel Carboni

An asterism is just a recognized pattern of stars that is not one the 88 official constellations. For example, one of the most famous (and largest) asterisms is the Big Dipper within the constellation Ursa Major. But this pretty chain of stars, ...

2010-01-27

What's that behind Titan? It's another of Saturn's moons: Tethys. The robotic Cassini spacecraft orbiting Saturn captured the heavily cratered Tethys slipping behind Saturn's atmosphere-shrouded Titan late last year. The largest crater on ...