Astronomy Picture Of the Day (APOD)Animation: Spiral Disk around a Black Hole
What would it look like to orbit a black hole? Many black holes are surrounded by swirling pools of gas known as accretion disks. These disks can be extremely hot, and much of the orbiting gas will eventually fall through the black hole's event horizon -- where it will never been seen again.
Lenticular Clouds over Mount Etna
What's happening above that volcano? Although Mount Etna is seen erupting, the clouds are not related to the eruption. They are lenticular clouds formed when moist air is forced upwards near a mountain or volcano.
Human as Spaceship
You are a spaceship soaring through the universe. So is your dog. We all carry with us trillions of microorganisms as we go through life. These multitudes of bacteria, fungi, and archaea have different DNA than you. Collectively called your microbiome, your shipmates outnumber your own cells.
1901 Photograph: The Orion Nebula
By the turn of the 20th century advances in photography contributed an important tool for astronomers. Improving photographic materials, long exposures, and new telescope designs produced astronomical images with details not visible at the telescopic eyepiece alone.
The Elephant s Trunk Nebula in Cepheus
Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Also known as vdB 142, the cosmic elephant's trunk is over 20 light-years long.
The Perseids and the Plough
Despite interfering moonlight, many denizens of planet Earth were able to watch this year's Perseid meteor shower. This pastoral scene includes local skygazers admiring the shower's brief, heavenly flashes in predawn hours near peak activity on August 13 from Nalati Grassland in Xinjiang, China.
Saturn Behind the Moon
What's that next to the Moon? Saturn. In its monthly trip around the Earth -- and hence Earth's sky -- our Moon passed nearly in front of Sun-orbiting Saturn earlier this week. Actually the Moon passed directly in front of Saturn from the viewpoints of a wide swath of Earth's Southern Hemisphere.
Supernova Cannon Expels Pulsar J0002
What could shoot out a neutron star like a cannon ball? A supernova. About 10,000 years ago, the supernova that created the nebular remnant CTB 1 not only destroyed a massive star but blasted its newly formed neutron star core -- a pulsar -- out into the Milky Way Galaxy.
Perseid Meteors over Slovakia
Tonight is a good night to see meteors. Comet dust will rain down on planet Earth, streaking through dark skies during the peak of the annual Perseid Meteor Shower. The featured composite image was taken during last year's Perseids from the Poloniny Dark Sky Park in Slovakia.
Arp 87: Merging Galaxies from Hubble
This dance is to the death. Along the way, as these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. The bridge...