Gamma-Ray Quasars
23.10.1995

Gamma rays are more than 10,000 times more energetic than visible light. If you could "see" gamma rays, the night sky would seem very different indeed. The bright object in the center of the false color gamma-ray image above is quasar 3C279, a nondescript, faint, starlike object in the visible sky.

Milky Way and Aurora over Antarctica
27.07.2015

It has been one of the better skies of this long night. In parts of Antarctica, not only is it winter, but the Sun can spend weeks below the horizon. At China's Zhongshan Station, people sometimes venture out into the cold to photograph a spectacular night sky.

LIGO Virgo GW170814 Skymap
28.09.2017

From around planet Earth three gravitational wave detectors have now reported a joint detection of ripples in spacetime, the fourth announced detection of a binary black hole merger in the distant Universe. The event...

A Perseid Meteor
11.08.1997

Tonight the Perseid Meteor Shower reaches its maximum. Grains of rocky ice will streak across the sky as they evaporate during entry into Earth's atmosphere. These ice chips were shed from Comet Swift-Tuttle. The Perseids result from the annual crossing of the Earth through Comet Swift-Tuttle's orbit.

LDN 1622: Dark Nebula in Orion
11.05.2007

The silhouette of an intriguing dark nebula inhabits this cosmic scene, based on images from the Palomar Observatory Sky Survey. Lynds' Dark Nebula (LDN) 1622 appears against a faint background of glowing hydrogen gas only easily seen in long telescopic exposures of the region.

APOD: 2025 March 4 Б A Quadruple Alignment over Italy
4.03.2025

Why does this Moon look so unusual? A key reason is its vivid red color. The color is caused by the deflection of blue light by Earth's atmosphere -- the same reason that the daytime sky appears blue. The Moon also appears unusually distorted.

NICER at Night
1.06.2019

A payload on board the International Space Station, the Neutron star Interior Composition Explorer (NICER) twists and turns to track cosmic sources of X-rays as the station orbits planet Earth every 93 minutes. During orbit nighttime, its X-ray detectors remain on.

7,000 Stars and the Milky Way
17.05.1997

This panorama view of the sky is really a drawing. It was made in the 1940s under the supervision of astronomer Knut Lundmark at the Lund Observatory in Sweden. To create the picture, draftsmen...

Red Cloudbow over Delaware
13.06.2018

What kind of rainbow is this? In this case, no rain was involved -- what is pictured is actually a red cloudbow. The unusual sky arc was spotted last month during sunset in Rehoboth Beach, Delaware, USA.

APOD: 2023 March 15 Б Jupiter and Venus Converge over Germany
15.03.2023

This was a sky to show the kids. Early this month the two brightest planets in the night sky, Jupiter and Venus, appeared to converge. At their closest, the two planets were separated by only about the angular width of the full moon.