Io: Moon over Jupiter
7.08.2016

How big is Jupiter's moon Io? The most volcanic body in the Solar System, Io (usually pronounced "EYE-oh") is 3,600 kilometers in diameter, about the size of planet Earth's single large natural satellite.

Jupiter Cloud Animation from Juno
21.05.2018

How do Jupiter's clouds move? To help find out, images taken with NASA's Juno spacecraft during its last pass near Jupiter have been analyzed and digitally extrapolated into a time-lapse video.

APOD: 2025 September 1 Б Callisto: Dirty Battered Iceball
1.09.2025

Its surface is the most densely cratered in the Solar System -- but what's inside? Jupiter's moon Callisto is a battered ball of dirty ice that is larger than the planet Mercury.

A Year of Resolving Backgrounds
30.12.2000

No matter which direction you look, no matter what type of light you see, the sky glows - but why? The sources of many of these background radiations have remained long-standing puzzles, but this millennial year brought some partial resolutions.

The Compton Observatory Turns Five
13.04.1996

Earlier this April, NASA's Compton Gamma Ray Observatory, completed its fifth successful year in orbit, exploring the gamma ray sky. Pictured is astronaut Jay Apt perched in the shuttle payload bay below the massive observatory. Compton is the largest civilian instrument ever flown - the whole observatory is roughly the size of a school bus.

Neutron Mars
4.09.2004

Looking for water on Mars, researchers using detectors on board the orbiting Mars Odyssey spacecraft have created this false-color global map of energetic neutrons from the otherwise Red Planet. What do neutrons have to do with water?

Rotating Titan in Infrared Light
15.02.2006

Titan is one of the strangest places in our Solar System. The only moon known with thick clouds, this unusual satellite of Saturn shows evidence of evaporating lakes created by methane rain. The clouds...

Mars Rover at Victoria Crater Imaged from Orbit
9.10.2006

An unusual spot has been found on Mars that scientists believe is not natural in origin. The spot appears mobile and is now hypothesized to be a robot created by an intelligent species alien to Mars. In fact, the spot appears to be NASA's robotic Opportunity rover currently rolling across Mars.

Solar System Portrait
13.02.2015

On another Valentine's Day 25 years ago, cruising four billion miles from the Sun, the Voyager 1 spacecraft looked back one last time to make this first ever Solar System family portrait. The complete portrait is a 60 frame mosaic made from a vantage point 32 degrees above the ecliptic plane.

Saturn, Titan, Rings, and Haze
5.05.2019

This is not a solar eclipse. Pictured here is a busy vista of moons and rings taken at Saturn. The large circular object in the center of the image is Titan, the largest moon of Saturn and one of the most intriguing objects in the entire Solar System.