Asteroids in the Distance
23.06.2002

Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak through our atmosphere daily, most evaporating quickly to nothing.

APOD: 2005 December 28- Smooth Sections on Asteroid Itokawa
28.12.2005

What are parts of this asteroid's surface so smooth? No one is yet sure, but it may have to do with the dynamics of an asteroid that is a loose pile of rubble rather than a solid rock.

Retrograde Mars
27.10.2014

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

APOD: 2024 December 8 Б Aurora around Saturns North Pole
8.12.2024

Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraft monitored Saturn's North Pole simultaneously during Cassini's final orbits around the gas giant in September 2017. During this time, Saturn's tilt caused its North Pole to be clearly visible from Earth.

Retrograde Mars
16.12.2003

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Sunset, Shadowrise
29.07.2010

From central Australia, this serene 360 degree panorama follows a clear horizon as twilight began on May 28. At left, a bright western sky is still illuminated by the setting Sun. But sweeping right...

Rocket Streak and Star Trails
30.01.2014

Fixed to a tripod and looking east across the Kennedy Space Center's Turn Basin, a camera captured these star trails as a series of short exposures over a three hour period on the evening of January 23rd.

Asteroids in the Distance
17.04.2005

Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak through our atmosphere daily, most evaporating quickly to nothing.

Islands of Four Mountains from Above
22.06.2010

Our Earth is covered by volcanoes. Volcanoes are breaks in the Earth's cool surface where hot liquid rock from the interior comes out -- sometimes suddenly. In the above image from the ASTER camera...

APOD: 2023 April 19 Б Auroral Storm over Lapland
19.04.2023

On some nights the sky is the best show in town. On this night, auroras ruled the sky, and the geomagnetic storm that created this colorful sky show originated from an increasingly active Sun.