X-Ray Moon
4.10.2003

This x-ray image of the Moon was made by the orbiting ROSAT (Röntgensatellit) Observatory in 1990. In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray moon, the darker half of the moon, and the x-ray sky background.

The Milky Way Over Devils Tower
29.07.2009

Was Devil's Tower once an explosive volcano? Famous for its appearance in films such as Close Encounters, the origin of Devil's Tower in Wyoming, USA is still debated, with a leading hypothesis holding that it is a hardened lava plume that probably never reached the surface to become a volcano.

The Tulip in the Swan
26.07.2012

Framing a bright emission region this telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula the glowing cloud of interstellar gas and dust is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101.

Distant Neutrinos Detected Below Antarctic Ice
1.09.2015

From where do these neutrinos come? The IceCube Neutrino Observatory near the South Pole of the Earth has begun to detect nearly invisible particles of very high energy. Although these rarely-interacting neutrinos pass through much of the Earth just before being detected, where they started remains a mystery.

Fermi Science Finals
23.07.2018

The Fermi Science Playoffs celebrate 10 years of the Fermi Gamma-ray Space Telescope's exploration of the high-energy universe. Surviving all early rounds of voting, these two finalists in the competion square off at last.

A Northern Winter Sky Panorama
24.12.2019

What stars shine in Earth's northern hemisphere during winter? The featured image highlights a number of bright stars visible earlier this month. The image is a 360-degree horizontal-composite panorama of 66 vertical frames taken consecutively with the same camera and from the same location at about 2:30 am.

APOD: 2023 July 24 Б Chemicals Glow as a Meteor Disintegrates
24.07.2023

Meteors can be colorful. While the human eye usually cannot discern many colors, cameras often can. Pictured here is a fireball, a disintegrating meteor that was not only one of the brightest the photographer has ever seen, but colorful.

The Radio Sky: Tuned to 408MHz
14.12.1997

Tune your radio telescope to 408MHz (408 million cycles per second) and check out the Radio Sky! You should find that frequency on your dial somewhere between US broadcast television channels 13 and 14.

NGC 1499: California Nebula
10.03.2005

Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun also lies within the Milky Way's Orion Arm, only about 1,500 light-years from the California Nebula.

Denizen of the Tarantula Nebula
7.04.1999

The star cluster at lower right, cataloged as Hodge 301, is a denizen of the Tarantula Nebula. An evocative nebula in the southern sky, the sprawling cosmic Tarantula is an energetic star forming region some 168,000 light-years distant in our neighboring galaxy the Large Magellanic Cloud.