APOD: 2024 April 22 Б Moon and Smoke Rings from Mt Etna
21.04.2024

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
7.03.2007

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
23.04.2017

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.

APOD: 2024 November 27 Б The Meteor and the Comet
26.11.2024

How different are these two streaks? The streak on the upper right is Comet Tsuchinshan-Atlas showing an impressive dust tail. The comet is a large and dirty iceberg that entered the inner Solar System and is shedding gas and dust as it is warmed by the Sun's light.

APOD: 2025 August 16 Б A Cool GIF of a 2025 Perseid
15.08.2025

The camera battery died about 2am local time on August 12, while shooting in the bright moonlit skies from a garden in Chastre, Brabant Wallon, Belgium, planet Earth. But not before it captured...

The Galactic Center in Infrared
8.07.2001

The center of our Galaxy is a busy place. In visible light, much of the Galactic Center is obscured by opaque dust. In infrared light, however, dust glows more and obscures less, allowing nearly one million stars to be recorded in the above photograph.