Cassini Spacecraft Crosses Saturns Ring Plane
23.02.2014

If this is Saturn, where are the rings? When Saturn's "appendages" disappeared in 1612, Galileo did not understand why. Later that century, it became understood that Saturn's unusual protrusions were rings and that when the Earth crosses the ring plane, the edge-on rings will appear to disappear.

Crescent Moon and Venus
6.03.2009

Last Friday, the Moon and Venus shared the early evening sky in a beautiful conjunction. Separated by only about 2 degrees, they also were both in a crescent phase. Just like our Moon, Venus can appear as a full disk or a thin crescent.

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.

Io Aurora
16.10.1998

Alluring aurora surrounding Io (eye-oh) appear as a ghostly glow while the volcanic moon orbits within Jupiter's dark shadow. Gas giant Jupiter is off to the right of this image, recorded in May by the robot Galileo spacecraft's solid state imaging camera from a distance of about 1.3 million kilometers.

Io at Sunset
20.01.2003

How tall are mountains on Jupiter's moon Io? One way to find out is to view them at sunset. Tall structures facing the Sun are then better-lit and cast long shadows. The above...

Star Trails Above Mauna Kea
20.12.2005

Is there a road to the stars? Possibly there are many, but the physical road pictured above leads up to the top of a dormant volcano that is a premier spot on planet Earth for observing stars and astronomical phenomena.

APOD: 2026 April 11 Б Artemis II: Flight Day 6
11.04.2026

On flight day 6 (April 6) the Artemis II mission achieved a historic lunar flyby. Rounding the lunar far side, the deep space maneuver marked humanity's first venture to the Moon since Apollo 17 in 1972.

Comet Clark is near the Edge.
27.05.2017

Sweeping through this stunning field of view, Comet 71P/Clark really is in the foreground of these cosmic clouds. The 2 panel telescopic mosaic is color enhanced and is about 5 degrees (10 full moons) across.

Mobius Arch Moonrise
28.02.2014

Only two days past full, February's moon shines through thin clouds, rising on the left in this fisheye night skyscape. The moonlight illuminates a weathered, rounded foreground in the Alabama Hills, conveniently located east of Mt. Whitney along the Sierra Nevada range in California, USA, planet Earth.

South Pole Lunar Eclipse
7.09.2007

The Moon was up continuously for 14 days in August -- when viewed from the South Pole. But during the total lunar eclipse on August 28, it circled only about 10 degrees above the horizon.