Riverbeds and Lakebeds Discovered on Saturn's Titan
24.01.2005

Methane rain, evaporating lakes, flowing rivers, and water ice-volcanoes all likely exist on Saturn's moon Titan, according to preliminary analyses of recent images taken by the successful Huygen's lander. A snaking...

Mimas: Small Moon with a Big Crater
25.04.1999

Mimas is one of the smaller moons of Saturn but shows one of the largest impact craters. In fact, if the impact had been much greater, it would have disrupted the entire satellite. The large crater has been named Herschel after the 1789 discoverer of Mimas, Sir William Herschel.

Saturn: 1993 2022
19.08.2022

Saturn is the most distant planet of the Solar System easily visible to the unaided eye. With this extraordinary, long-term astro-imaging project begun in 1993, you can follow the ringed gas giant for one Saturn year as it wanders once around the ecliptic plane, finishing a single orbit around the Sun by 2022.

Saturn and ISS
9.07.2022

Soaring high in skies around planet Earth, bright planet Saturn was a star of June's morning planet parade. But very briefly on June 24 it posed with a bright object in low Earth orbit, the International Space Station.

Iridescent Clouds Over Aiguille de la Tsa
14.10.2003

Before the sun rose over the mountains, iridescent colors danced across the sky. The unexpected light show was caused by a batch of iridescent clouds, and captured on film in early September in Arolla, Wallis, Switzerland. The peak in the foreground of the above image is Aiguille de la Tsa.

A Hole Punch Cloud Over Alabama
12.01.2004

What could create a huge hole the clouds? Such a hole, likely hundreds of meters across, was photographed last month from a driveway near Mobile, Alabama, USA. Very unusual to see, hole-punch clouds like this are still the topic of meteorological speculation. A leading hypothesis holds that the hole-punch cloud is caused by falling ice-crystals.

Aurora Over Clouds
10.09.2003

Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle.

Nacreous Clouds over Lapland
9.02.2023

Vivid and lustrous, wafting iridescent waves of color wash across this skyscape from Kilpisjцrvi, Finland. Known as nacreous clouds or mother-of-pearl clouds, they are rare. But their unforgettable appearance was captured looking south at 69 degrees north latitude at sunset on January 24.

APOD: 2023 February 12 Б Mammatus Clouds over Nebraska
12.02.2023

When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms.

Uranian Moons, Rings, And Clouds
26.11.1997

The giant planet Uranus is faint and featureless when viewed in visible light. But this pair of near-infrared mosaics from the Hubble Space Telescope's NICMOS camera reveals moons, rings, and clouds of this distant gas planet.