All the Water on Planet Earth
26.09.2022

How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius.

Europa's Ice Rafts
10.04.1997

The surface of Jupiter's moon Europa has shifted. Photographs released yesterday of Europa's surface taken by the spacecraft Galileo show that the smooth moon's icy surface is sometimes like a giant scrambled jigsaw puzzle. Pieces of Europa's surface, identifiable above, have rafted to new locations.

Twilight in a Western Sky
31.03.2018

A slender crescent Moon and inner planets Venus and Mercury never wander far from the Sun in planet Earth's skies. In the fading evening twilight of March 18, they line up near the western horizon in this atmospheric skyscape.

Galileo Views Io Eruption
15.08.1996

Io's surface is active. Geyser-like eruptions from volcanoes on this Jovian moon were seen by both Voyager spacecraft in 1979 and were also spotted this year in late June by Galileo's camera from a distance of about 600,000 miles.

Saturn, Tethys, Rings, and Shadows
5.04.2015

Seen from ice moon Tethys, rings and shadows would display fantastic views of the Saturnian system. Haven't dropped in on Tethys lately? Then this gorgeous ringscape from the Cassini spacecraft will have to do for now.

Mercury from Passing BepiColombo
28.06.2022

Which part of the Moon is this? No part -- because this is the planet Mercury. Mercury's old surface is heavily cratered like that of Earth's Moon. Mercury, while only slightly larger than Luna, is much denser and more massive than any Solar System moon because it is made mostly of iron.

Herschel Crater on Mimas
13.08.2022

Mimas, small 400 kilometer-diameter moon of Saturn, is host to 130 kilometer-diameter Herschel crater, one of the larger impact craters in the entire Solar System. The robotic Cassini spacecraft orbiting Saturn in 2010 recorded...

APOD: 2023 October 15 Б An Eclipse Tree
15.10.2023

Yes, but can your tree do this? If you look closely at the ground in the featured image, you will see many images of yesterday's solar eclipse -- created by a tree. Gaps between...

Saturn and Titan from Cassini
24.03.2008

Spectacular vistas of Saturn and its moon continue to be recorded by the Cassini spacecraft. Launched from Earth in 1997, robotic Cassini entered orbit around Saturn in 2004 and has revolutionized much of humanity's knowledge of Saturn, its expansive and complex rings, and it many old and battered moons.

A Total Solar Eclipse Close Up in Real Time
12.09.2017

How would you feel if the Sun disappeared? Many eclipse watchers across the USA surprised themselves with the awe that they felt and the exclamations that they made as the Sun momentarily disappeared behind the Moon.