APOD: 2025 August 12 Б Perseids from Perseus
12.08.2025

Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks tonight is known as the Perseids -- the meteors all appear to come from a radiant toward Perseus.

Southern Moonscape
6.02.2020

The Moon's south pole is near the top of this detailed telescopic view. Looking across the rugged southern lunar highlands it was captured from southern California, planet Earth. At the Moon's third quarter phase the lunar terminator, the sunset shadow line, is approaching from the left.

APOD: 2024 January 8 Б The Phases of Venus
8.01.2024

Venus goes through phases. Just like our Moon, Venus can appear as a full circular disk, a thin crescent, or anything in between. Venus, frequently the brightest object in the post-sunset or pre-sunrise sky, appears so small, however, that it usually requires binoculars or a small telescope to clearly see its current phase.

Lava Flows on Venus
23.03.2004

The hot surface of Venus shows clear signs of ancient lava flows. Evidence of this was bolstered by the robot spacecraft Magellan, which orbited Venus in the early 1990s. Using imaging radar, Magellan was able to peer beneath the thick perpetual clouds that cover Earth's closest planetary neighbor.

Moon and Planets Sky
26.03.2004

Look up into the sky tonight and without a telescope or binoculars you might have a view like this one of Moon, planets and stars. The lovely photo was taken on March 23rd, and captures the crescent Moon on the horizon with Venus above it. Both brilliant celestial bodies are over-exposed.

Driving Toward a Sun Halo
13.06.2006

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.

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.

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.