Astronomy Picture of the Day

2012-10-11

North America at night is easy to recognize in this view of our fair planet from orbit, acquired by the Suomi-NPP satellite on October 8. The spectacular waves of visible light emission rolling above the Canadian provinces of Quebec and Ontario ...

2012-10-10

In myth, Atlas holds up the heavens, but in this scene they seem to pivot around a lighthouse beacon. Photographed with a camera fixed to a tripod, the well-planned image, a composite of 30 one minute exposures, records star trails in the ...

2012-10-09

It's easy to get lost following the intricate filaments in this detailed mosaic image of faint supernova remnant Simeis 147 (S147). Also cataloged as Sh2-240, it covers nearly 3 degrees or 6 full moons on the sky. That's about 150 light-years at ...

2012-10-08

Ghostly in appearance, Abell 39 is a remarkably simple, spherical nebula about five light-years across. Well within our own Milky Way galaxy, the cosmic sphere is roughly 7,000 light-years distant toward the constellation Hercules. Abell 39 is a ...

2012-10-07

Are square A and B the same color? They are! To verify this, either run your cursor over the image or click here to see them connected. The above illusion, called the same color illusion, illustrates that purely human observations in science may ...

2012-10-06

Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star ...

2012-10-05 Ole C. Salomonsen

What's happening behind that mountain? A convergence of variable sky spectacles. One night in mid-September near Troms?, Norway, high red aurora could be seen shimmering through lower green aurora in a way that created a striking and somewhat ...

2012-10-04 Martin Pugh

A mere seven hundred light years from Earth, in the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this ...

2012-10-03 Juan Carlos Casado

Sometimes it's hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing ...

2012-10-02

Fresh evidence of an ancient stream has been found on Mars. The robotic rover Curiosity has run across unusual surface features that carry a strong resemblance to stream banks on Earth. Visible in the above image, for example, is a small ...