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: 2024 July 16 Б Cometary Globules
16.07.2024

What are these unusual interstellar structures? Bright-rimmed, flowing shapes gather near the center of this rich starfield toward the borders of the nautical southern constellations Pupis and Vela. Composed of interstellar gas and dust, the grouping of light-year sized cometary globules is about 1300 light-years distant.

APOD: 2026 February 8 Б Active Sunspot Region 4366 Crosses the Sun
8.02.2026

An unusually active sunspot region is now crossing the Sun. The region, labelled AR 4366, is much larger than the Earth and has produced several powerful solar flares over the past ten days. In the featured image, the region is marked by large and dark sunspots toward the upper right of the Sun's disk.

The T Tauri Star Forming System
4.06.2001

What did the Sun look like before there were planets? A prototype laboratory for the formation of low mass stars like our Sun is the T Tauri system, one of the brighter star systems toward the constellation of Taurus. In young systems, gravity causes a gas cloud to condense.

Trifid Pillars and Jets
30.12.2001

Dust pillars are like interstellar mountains. They survive because they are more dense than their surroundings, but they are being slowly eroded away by a hostile environment. Visible in the above picture...

Martian Dunes and the Shadow of Opportunity
24.03.2009

Human made robots continue to roll across the surface of Mars. Both Opportunity and its sister rover Spirit are in their sixth year on Mars, exploring the red planet for years longer than original expectations.

Curiosity on Mars: A Wall of Gale Crater
15.08.2012

If you could stand on Mars, what would you see? The above image is a digitally re-colored approximation of what you might see if the above Martian landscape had occurred on Earth. Images from...

Suiting Up for the Moon
1.04.2015

How will cows survive on the Moon? One of the most vexing questions asked about space, scientists have spent decades debating this key issue. Finally, after extensive computer modeling and over a dozen midnight milkings, engineers have designed, built, and now tested the new Lunar Grazing Module (LGM), a multi-purpose celestial bovine containment system.

The Extraordinary Spiral in LL Pegasi
8.07.2018

What created the strange spiral structure on the upper left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.

Iridescent Clouds over Sweden
15.01.2020

Why would these clouds multi-colored? A relatively rare phenomenon in clouds known as iridescence can bring up unusual colors vividly or even a whole spectrum of colors simultaneously. These polar stratospheric clouds clouds, also known as nacreous and mother-of-pearl clouds, are formed of small water droplets of nearly uniform size.