From the Northern to the Southern Cross
27.01.2014

There is a road that connects the Northern to the Southern Cross but you have to be at the right place and time to see it. The road, as pictured above, is actually...

NGC 3521: Galaxy in a Bubble
2.04.2021

Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years away, toward the constellation Leo. Relatively bright in planet Earth's sky, NGC 3521 is easily visible in small telescopes but often overlooked by amateur imagers in favor of other Leo spiral galaxies, like M66 and M65.

IRAS Orion
31.07.1998

Do you recognize the constellation Orion? This striking but unfamiliar looking picture of the familiar Orion region of the sky was produced using survey data from the InfraRed Astronomical Satellite (IRAS). It combines information...

Chandra Resolves the Hard X Ray Background
14.01.2000

It is everywhere but nobody knew why. In every direction at all times, the sky glows in X-rays. The X-ray background phenomenon was discovered over 35 years ago, soon after the first X-ray satellites were launched, and has since gone unexplained.

Noctilucent Clouds Over Germany
24.06.2009

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.

NGC 3521: Galaxy in a Bubble
15.09.2011

Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years away, toward the constellation Leo. Relatively bright in planet Earth's sky, NGC 3521 is easily visible in small telescopes but often overlooked by amateur imagers in favor of other Leo spiral galaxies, like M66 and M65.

Ancients of Sea and Sky
19.06.2018

They may look like round rocks, but they're alive. Moreover, they are modern versions of one of the oldest known forms of life: stromatolites. Fossils indicate that stromatolites appeared on Earth about 3.7 billion years ago -- even before many of the familiar stars in the modern night sky were formed.

M83: Star Streams and a Thousand Rubies
3.07.2024

Big, bright, and beautiful, spiral galaxy M83 lies a mere twelve million light-years away, near the southeastern tip of the very long constellation Hydra. About 40,000 light-years across, M83 is known as the Southern Pinwheel for its pronounced spiral arms.

APOD: 2025 September 16 Б New Comet SWAN25B over Mexico
16.09.2025

A newly discovered comet is already visible with binoculars. The comet, C/2025 R2 (SWAN) and nicknamed SWAN25B, is brightening significantly as it emerges from the Sun's direction and might soon become visible on your smartphone -- if not your eyes.

Star Cluster R136 Bursts Out
30.07.2001

In the center of star-forming region 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. Known as R136, the cluster's energetic stars are breaking out of the cocoon of gas and dust from which they formed.