Saturns Rings from the Other Side
22.06.2005

What do Saturn's rings look like from the other side? From Earth, we usually see Saturn's rings from the same side of the ring plane that the Sun illuminates them. Geometrically...

Moon Occults Saturn
8.05.1999

On September 18, 1997, many stargazers in the U. S. were able to watch a lovely early morning lunar occultation as a bright Moon passed in front of Saturn. Using a 1.2 meter reflector, astronomer Kris Stanek had an excellent view of this dream-like event from the Whipple Observatory atop Arizona's Mount Hopkins.

A Solar Eclipse Quilt
13.11.2012

Some people are so inspired by solar eclipses that they quilt. Pictured above is a resulting textile from one such inspiration. The 38x38 inch quilt offers impressions of a total annular eclipse, when the Moon is too far from the Earth to cover the entire Sun, witnessed in Spain in October of 2005.

Galileo s Europa
19.09.2003

Launched in 1989 and looping through the jovian system since late 1995, the voyage of NASA's Galileo spacecraft will soon come to an end. The spacecraft has been targeted to plunge directly into Jupiter this Sunday, September 21st, at about 30 miles per second.

A New Year s Crescent
1.01.2014

That's not the young crescent Moon poised above the western horizon at sunset. Instead it's Venus in a crescent phase, captured with a long telephoto lens from Quebec City, Canada, planet Earth on a chilly December 30th evening. The very bright celestial beacon is droping lower into the evening twilight every day.

APOD: 2024 April 8 Б The Changing Ion Tail of Comet Pons Brooks
8.04.2024

How does a comet tail change? It depends on the comet. The ion tail of Comet 12P/PonsБBrooks has been changing markedly, as detailed in the featured image sequenced over nine days from March 6 to 14 (top to bottom).

The Earth Also Rises
25.03.2000

The Lunar Orbiter 1 spacecraft was launched in 1966 to map the lunar surface in preparation for the Apollo moon landings. NASA's plucky robotic explorer performed its job well and pioneered this classic view of the Earth poised above the lunar horizon.

APOD: 2025 April 6 Б Moonquakes Surprisingly Common
6.04.2025

Why are there so many moonquakes? Analyses of seismometers left on the moon during the Apollo moon landings reveal a surprising number of moonquakes occurring within 100 kilometers of the surface. In fact, 62 moonquakes were detected in data recorded between 1972 and 1977.

APOD: 2025 January 15 Б Wolf Moon Engulfs Mars
15.01.2025

Does the Moon ever engulf Mars? Yes, but only in the sense that it moves in front, which happens on rare occasions. This happened just yesterday, though, as seen from some locations in North America and western Africa.

Venus: Earths Cloudy Twin
16.05.2004

This picture by the Galileo spacecraft shows just how cloudy Venus is. Venus is very similar to Earth in size and mass - and so is sometimes referred to as Earth's sister planet - but Venus has a quite different climate.