Astronomy Picture of the Day

2011-01-04 Juan José Manzano

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just ...

2011-01-03 Jimmy Westlake

If you can find Orion, you might be able to find the Winter Hexagon. The Winter Hexagon involves some of the brightest stars visible, together forming a large and easily found pattern in the winter sky of Earth's northern hemisphere. The stars ...

2011-01-02

Here is what the Earth looks like during a solar eclipse. The shadow of the Moon can be seen darkening part of Earth. This shadow moved across the Earth at nearly 2000 kilometers per hour. Only observers near the center of the dark circle see a ...

2011-01-01 Adam Block

Celebrate the New Year with the Fireworks Galaxy! Also known as NGC 6946, the big, beautiful spiral galaxy is located just 10 million light-years away, behind a veil of foreground dust and stars in the high and far-off constellation of Cepheus. ...

2010-12-31 Tamas Ladanyi

Looking back on the year, have you wondered where the Sun was in the sky each day during 2010 at exacty 9am UT? Of course you have. Search no further for the answer! It was somewhere along this celestial figure 8 curve known as an analemma. ...

2010-12-30 Adam Block

In this beautiful celestial still life composed with a cosmic brush, dusty nebula NGC 2170 shines at the upper left. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae, a compact red emission region, ...

2010-12-29 Grupo de Observadores Astronómicos de Tenerife

Hugging the horizon, a dark red Moon greeted early morning skygazers in eastern Atlantic regions on December 21, as the total phase of 2010's Solstice Lunar Eclipse began near moonset. This well composed image of the geocentric celestial event is ...

2010-12-28 Tunç Tezel

Sometimes the sky itself seems to glow. Usually, this means you are seeing a cloud reflecting sunlight or moonlight. If the glow appears as a faint band of light running across the whole sky, you are probably seeing the combined light from the ...

2010-12-27

Are the nearest galaxies distributed randomly? A plot of over one million of the brightest "extended sources" detected by the Two Micron All Sky Survey (2MASS) shows that they are not. The vast majority of these infrared extended sources are ...

2010-12-26 Donegal Skies

Orion always comes up sideways ... and was caught in the act earlier this month by over a snowy landscape in Donegal, Ireland. To compose this serene picture, the photographer found a picturesque setting to the east, waited until after sunset, ...