Astronomy Quilt of the Week
16.10.2005

Demonstrating her mastery of a traditional astronomical imaging technique quilter and astronomy enthusiast Judy Ross has produced this spectacular composition of "Astronomy Quilt Piece of the Week". Her year-long effort resulted in an arrangement...

A Full Sky Aurora Over Norway
3.01.2012

Higher than the highest building, higher than the highest mountain, higher than the highest airplane, lies the realm of the aurora. Auroras rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from energetic electrons and protons striking molecules in the Earth's atmosphere.

The Pleiades Star Cluster
3.01.2005

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

NGC 6188 and NGC 6164
28.12.2012

Fantastic shapes lurk in clouds of glowing hydrogen gas in NGC 6188, about 4,000 light-years away. The emission nebula is found near the edge of a large molecular cloud unseen at visible wavelengths, in the southern constellation Ara.

Light from the First Stars
2.01.2007

What were the first stars like? No one is yet sure. Our Sun is not a first-generation star. It is not even second generation. The first stars to appear in the universe likely came and went about 13 billion years ago.

What the Hubble Saw
25.11.2004

In this striking 41 inch by 38 inch quilt, astronomy enthusiast Judy Ross has interpreted some of the Hubble Space Telescope's best galactic and extragalactic vistas. Featured in past APODs, clockwise from...

47 Tuc: A Great Globular Cluster of Stars
26.08.2008

Stars come in bunches. Of the over 200 globular star clusters that orbit the center of our Milky Way Galaxy, 47 Tucanae is the second brightest globular cluster (behind Omega Centauri). Light takes about...

Gamma Ray Earth
31.03.2005

The pixelated planet above is actually our own planet Earth seen in gamma rays - the most energetic form of light. In fact, the gamma rays used to construct this view pack over 35 million electron volts (MeV) compared to a mere two electron volts (eV) for a typical visible light photon.

Tungurahua Erupts
18.09.2007

Volcano Tungurahua erupted spectacularly last year. Pictured above, molten rock so hot it glows visibly pours down the sides of the 5,000-meter high Tungurahua, while a cloud of dark ash is seen being ejected toward the left. Wispy white clouds flow around the lava-lit peak, while a star-lit sky shines in the distance.

Vanishing Umbra
8.04.2006

During the March 29 total solar eclipse, the Moon's dark central shadow or umbra is vanishing beyond the horizon in this dramatic view of the landscape a few kilometers southeast of Incesu, Anatolia, Turkey. The large, snow covered mountain in the distance is 3,250 meter high volcano Hasan Dag.