Eclipsosaurus Rex
7.10.2017

We live in an era where total solar eclipses are possible because at times the apparent size of the Moon can just cover the disk of the Sun. But the Moon is slowly moving away from planet Earth. Its distance is measured to increase about 1.5 inches (3.8 centimeters) per year due to tidal friction.

Sun and Moon Halo
3.04.2015

Two pictures captured on April 1 are combined in this creative day and night composite. Separated in time by about 10 hours the images otherwise match, looking along the coast at Östersund Sweden.

Lunar Occultation of Mercury
28.02.2026

Fans of the western sky after sunset have lately enjoyed this month's remarkable array of bright planets. Witnessed from some locations, on February 18 planet Mercury even appeared to slide behind the Moon, an event known as a lunar occultation.

A Twilight Occultation
10.12.2010

A thin, one day old crescent Moon hugged the western horizon after sunset on Monday, December 6. The Moon also occulted or passed in front of Mars. But only some well-placed skygazers along a band through North America were able to catch this lunar occultation's final act in fading twilight.

Beneath Venus' Clouds
24.09.1996

If the thick clouds covering Venus were removed, how would the surface appear? Using an imaging radar technique, the Magellan spacecraft was able to lift the veil from the Face of Venus and produce this spectacular high resolution imageof the planet's surface.

Nocturnal: Scenes from the Southern Night
6.08.2012

Have you ever seen the night sky change? It does -- sometimes in beautiful and unexpected ways. To see it, though, usually requires patience. The above award winning video shows several of the possible changes in dramatic fashion with a time lapse video.

Into the Shadow
24.01.2020

On January 21, 2019 moonwatchers on planet Earth saw a total lunar eclipse. In 35 frames this composite image follows the Moon that night as it crossed into Earth's dark umbral shadow. Taken...

APOD: 2026 March 2 Б The Dusty Surroundings of Orion and the Pleiades
2.03.2026

How well do you know the night sky? OK, but how well can you identify famous sky objects in a very deep image? Either way, here is a test: see if you can find some well-known night-sky icons in a deep image filled with filaments of normally faint dust and gas.

A Triangular Shadow of a Large Volcano
5.07.2011

Why does the shadow of this volcano look like a triangle? The Mount Teide volcano itself does not have the strictly pyramidal shape that its geometric shadow might suggest. The triangle shadow phenomena is not unique to the Mt. Teide, though, and is commonly seen from the tops of other large mountains and volcanoes.

A Triangular Shadow of a Large Volcano
9.06.2019

Why does the shadow of this volcano look like a triangle? The Mount Teide volcano itself does not have the strictly pyramidal shape that its geometric shadow might suggest. The triangle shadow phenomena is not unique to the Mt. Teide, though, and is commonly seen from the tops of other large mountains and volcanoes.