Astronomy Picture Of the Day (APOD)Thors Helmet Emission Nebula
This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor's Helmet. Heroically sized even for a Norse god, Thor's Helmet spans about 30 light-years across. In fact, the helmet is more...
Dark Matter in a Simulated Universe
Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...
Orionid Meteors from Orion
Meteors have been shooting out from the constellation of Orion. This was expected, as October is the time of year for the Orionids Meteor Shower. Pictured here, over a dozen meteors were caught in successively added exposures last weekend over Wulan Hada volcano in Inner Mongolia, China.
Night on a Spooky Planet
What spooky planet is this? Planet Earth of course, on a dark and stormy night in 2013 at Hverir, a geothermally active area along the volcanic landscape in northeastern Iceland. Geomagnetic storms produced...
NGC 6369: The Little Ghost Nebula
Wraithlike NGC 6369 is a faint apparition in night skies popularly known as the Little Ghost Nebula. It was discovered by 18th century astronomer Sir William Herschel as he used a telescope to explore the medicinal constellation Ophiucus. Herschel historically classified the round and planet-shaped nebula as a Planetary Nebula.
Mirach s Ghost
As far as ghosts go, Mirach's Ghost isn't really that scary. Mirach's Ghost is just a faint, fuzzy galaxy, well known to astronomers, that happens to be seen nearly along the line-of-sight to Mirach, a bright star. Centered in this star field, Mirach is also called Beta Andromedae.
NGC 7635: Bubble in a Cosmic Sea
Adrift in a cosmic sea of stars and glowing gas the delicate, floating apparition left of center in this widefield view is cataloged as NGC 7635, the Bubble Nebula. A mere 10 light-years wide, the tiny Bubble Nebula was blown by the winds of a massive star.
Marius Hills: Holes in the Moon
Could humans live beneath the surface of the Moon? This intriguing possibility was bolstered in 2009 when Japan's Moon-orbiting SELENE spacecraft imaged a curious hole beneath the Marius Hills region on the Moon, possibly a skylight to an underground lava tube.
Where Your Elements Came From
The hydrogen in your body, present in every molecule of water, came from the Big Bang. There are no other appreciable sources of hydrogen in the universe. The carbon in your body was made by nuclear fusion in the interior of stars, as was the oxygen.
NGC 4993: The Galactic Home of an Historic Explosion
That reddish dot -- it wasn't there before. It's the dot to the upper left of galaxy NGC 4993's center, do you see it? When scanning the large field of possible locations...