Vintage Gamma Rays
6.04.2002

Gamma-rays are the most energetic form of electromagnetic radiation. But these high energy photons penetrate and interact in normal materials and cannot be focused by lenses and mirrors like those in optical telescopes. So how do you make an image in gamma-ray light?

Surveyor At Mars
6.10.1997

Mars Global Surveyor achieved Martian orbit on September 11 and began aerobraking into its final mapping orbit, a process that will take until March next year. Anticipating the labors ahead, Mars Orbital Camera operators have begun acquiring test images.

Enceladus Backlit by Saturn
8.02.2012

This moon is shining by the light of its planet. Specifically, a large portion of Enceladus pictured above is illuminated primarily by sunlight first reflected from the planet Saturn. The result is that the normally snow-white moon appears in the gold color of Saturn's cloud tops.

Observatory, Mountains, Universe
29.12.2014

The awesomeness in this image comes in layers. The closest layer, in the foreground, contains the Peak Terskol Observatory located in the northern Caucasus Mountains of Russia. The white dome over the 2-meter telescope is clearly visible. The observatory is located on a shoulder of Mt.

The Colorful Moon
16.03.2002

Do you recognize the Earth's Moon when you see it? The crazy, patchwork appearance of the false-color image makes this almost full view of the Moon's familiar near side look very strange.

Cassiopeia A Light Echoes in Infrared
15.06.2005

Why is the image of Cassiopeia A changing? Two images of the nearby supernova remnant taken a year apart in infrared light appear to show outward motions at tremendous speeds. This was unexpected since the supernova that created the picturesque nebula was seen 325 years ago. The reason is likely light echoes.

Skylights Over Libya
28.12.2010

Sometimes the sky itself seems to glow. Usually, this means you are seeing a cloud reflecting sunlight or moonlight. If the glow appears as a faint band of light running across the whole sky, you are probably seeing the combined light from the billions of stars that compose our Milky Way Galaxy.

The M81 Galaxy Group Through the Integrated Flux Nebula
13.03.2012

Large galaxies and faint nebulae highlight this deep image of the M81 Group of galaxies. First and foremost in the wide-angle 12-hour exposure is the grand design spiral galaxy M81, the largest galaxy visible in the image.

APOD: 2025 October 13 Б Lemmon Tree
13.10.2025

The tree is not in danger. That's because the comet pictured just above it, Comet C/2025 A6 (Lemmon), is far in the distance, well away from the Earth. Comet Lemmon now continues...

Red Sun through Wildfire Smoke
30.07.2026

This could be the view from an exoplanet orbiting around a red dwarf star, but it is our own Sun. This image was taken on July 22, 2026, in the Okanagan region in the Canadian province of British Columbia.