Astronomy Picture of the Day

2011-07-22

Nix and Hydra were first introduced to human eyes in Hubble Space Telescope images from May 2005, as Pluto's second and third known moons. Now Hubble images have revealed a fourth satellite for the icy, dwarf planet. Provisionally designated P4, ...

2011-07-21 John Sarkissian

The Parkes 64 meter radio telescope is known for its contribution to human spaceflight, famously supplying television images from the Moon to denizens of planet Earth during Apollo 11. The enormous, steerable, single dish looms in the foreground ...

2011-07-20

Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above. Under usual circumstances, a pretty ...

2011-07-19

What does the surface of asteroid Vesta look like? The brightest asteroid in the Solar System and the object which takes up about 10 percent of the entire mass of the main asteroid belt had never been seen up close before. Over the past few ...

2011-07-17 Peter Wienerroither

You could be the first person ever to take a real single-exposure image like this. The above image from Vienna, Austria is not real in the sense that the 360 degree star trails in the sky appear only because of a digital trick. Real star trails ...

2011-07-16 Babak Tafreshi

A starry night over the city of Dubai in the United Arab Emirates is really not so starry. In fact, the Moon is the only celestial beacon to come close to competing with city lights in this night skyscape, a situation all too familiar to urban ...

2011-07-15

NGC 3314 is actually two large spiral galaxies which just happen to almost exactly line up. The foreground spiral is viewed nearly face-on, its pinwheel shape defined by young bright star clusters. But against the glow of the background galaxy, ...

2011-07-14

Neptune rotates once on its axis in about 16 hours. So, spaced about 4 hours apart these 4 images of the solar system's most distant gas giant cover one Neptune day. Recorded by the Hubble Space Telescope in late June they combine exposures made ...

2011-07-13

For the last time, the US Space Shuttle has approached the International Space Station (ISS). Following a dramatic launch from Cape Canaveral last week that was witnessed by an estimated one million people, Space Shuttle Atlantis on STS-135 ...

2011-07-12 Bob Franke

Here is one of the largest objects that anyone will ever see on the sky. Each of these fuzzy blobs is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies. The cluster is seen through a foreground of faint ...