Noctilucent Clouds Tour France
9.07.2016

Bright noctilucent or night shining clouds are not familiar sights from northern France. But these electric-blue waves coursed through skies over the small town of Wancourt in Pas-de-Calais on July 6, just before the dawn.

Noctilucent Clouds over Paris Fireworks
10.07.2018

It's northern noctilucent cloud season -- perhaps a time to celebrate! Composed of small ice crystals forming only during specific conditions in the upper atmosphere, noctilucent clouds may become visible at sunset during late summer when illuminated by sunlight from below.

Sand Dunes Thawing on Mars
24.09.2019

What are these strange shapes on Mars? Defrosting sand dunes. As spring dawned on the Northern Hemisphere of Mars, dunes of sand near the pole, as pictured here in late May by ESA's ExoMars Trace Gas Orbiter, began to thaw.

APOD: 2024 April 22 Б Moon and Smoke Rings from Mt Etna
22.04.2024

Yes, but can your volcano do this? To the surprise of some, Mt. Etna emits, on occasion, smoke rings. Technically known as vortex rings, the walls of the volcano slightly slow the outside of emitted smoke puffs, causing the inside gas to move faster.

A Radar Image of Venus
15.05.2001

The largest radio telescopes in the world are working together to create a new map of the surface of Venus. The surface of Venus is unusually hidden by a thick atmosphere of mostly carbon dioxide gas. These thick clouds are transparent, however, to radar signals sent and received from Earth.

Saturn's Rings Seen Sideways
29.04.1996

Saturn's rings are actually very thin. This picture from the Hubble Space Telescope was taken on August 6, 1995 when the rings lined up sideways as seen from Earth. Saturn's largest moon Titan is seen on the left, and Titan's shadow can be seen on Saturn's cloud tops!

The Dotted Dunes of Mars
31.08.2004

What causes the black dots on dunes on Mars? As spring dawns on the Northern Hemisphere of Mars, dunes of sand near the poles being to defrost. Thinner regions of ice typically thaw first revealing sand whose darkness soaks in sunlight and accelerates the thaw.

Red Moon Triple
29.10.2004

Some thought of baseball and some thought of Halloween during October 27th's widely viewed total lunar eclipse. Sliding through Earth's shadow, the Moon turned haunting shades of red and orange during the eclipse's total phase.

Eclipsed Moon and Stars
8.03.2007

This dramatic image features a dark red Moon during a total lunar eclipse -- celestial shadow play enjoyed by many denizens of planet Earth last Saturday. Recorded near Wildon, Austria, the picture is a composite...

A White Battle in the Black Sea
24.04.2017

Trillions have died in the Earth's seas. Calcified shields of the dead already make up the white cliffs of Dover. The battle between ball-shaped light-colored single-celled plants -- phytoplankton called coccolithophores -- and even smaller, diamond-shaped viruses dubbed coccolithoviruses -- has raged for tens of millions of years.