Milky Way with Airglow Australis
4.09.2015

After sunset on September 1, an exceptionally intense, reddish airglow flooded this Chilean winter night skyscape. Above a sea of clouds and flanking the celestial Milky Way, the airglow seems to ripple and flow across the northern horizon in atmospheric waves.

APOD: 2024 April 29 Б Comet, Planet, Moon
29.04.2024

Three bright objects satisfied seasoned stargazers of the western sky just after sunset earlier this month. The most familiar was the Moon, seen on the upper left in a crescent phase. The rest of the Moon was faintly visible by sunlight first reflected by the Earth.

APOD: 2026 April 21 Б Three Sky Arches over Snowy Alps
21.04.2026

Why are there three arches across the sky instead of two? Last month, after being dropped off by a helicopter at a high mountain peak in the Alps near the Swiss Italian border, an adventurous astrophotographer expected two arches of our Milky Way galaxy to be visible during the night.

ISS: Sunlight to Shadow
28.02.2008

Orbiting 400,000 kilometers above the Earth, the Moon slid into Earth's shadow to begin last week's total lunar eclipse. Of course the International Space Station (ISS) slides into Earth's shadow every 90 minutes, the time it takes it to complete one orbit at an altitude of about 400 kilometers.

Planet Earth at Blue Hour
11.10.2019

Nature photographers and other fans of planet Earth always look forward to the blue hour. That's the transition in twilight, just before sunrise or after sunset, when the Sun is below the horizon but land and sky are still suffused with beautiful bluish hues of light.

A Sun Halo Beyond Stockholm
10.01.2011

What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a large lens. In the above case, however, there are actually millions of lenses: ice crystals. As water freezes in the upper atmosphere, small, flat, six-sided, ice crystals might be formed.

Saturn and Mars visit Milky Way Star Clouds
10.05.2016

Planets, stars, nebulas and a galaxy -- this impressive image has them all. Closest to home are the two planets Mars (right) and Saturn (center), visible as the two bright orange spots in the upper half of the featured image.

APOD: 2026 April 20 Б Comet R3 PanSTARRS over a Himalayan Valley
20.04.2026

The best way to see comet R3 PanSTARRSБs long tail is with a camera. This week, the recently brightened comet appears in northern skies to the east just before dawn, but is only barely visible to the unaided eye.

Perseid Night at Yosemite
18.08.2016

The 2016 Perseid meteor shower performed well on the night of August 11/12. The sky on that memorable evening was recorded from a perch overlooking Yosemite Valley, planet Earth, in this scene composed of 25 separate images selected from an all-night set of sequential exposures.

Gemini Stars Pollux and Castor
16.05.2017

Who are the twins of Gemini? It terms of astronomical objects, the famous constellation is dominated by two bright stars: Pollux (left) and Castor (right). Pictured, the two stars stand out because they are so bright, so close together both in angle and brightness, but so different in color.