Stereo Helene
5.01.2013

Get out your red/blue glasses and float next to Helene, small, icy moon of Saturn. Appropriately named, Helene is one of four known Trojan moons, so called because it orbits at a Lagrange point. A Lagrange point is a gravitationally stable position near two massive bodies, in this case Saturn and larger moon Dione.

Dust Hip Deep on Phobos
14.09.1998

Landing on the Martian Moon Phobos might be harder than previously thought. The reason: Moon dust. Recent photographs of Phobos have indicated that a layer of fine powder estimated to be a meter deep covers the whole surface. Evidence comes from infrared pictures that indicate the rapid speed that Phobos' surface cools after sunset.

A Crescent Sunrise
17.08.1999

Normally, the Moon shows phases, but the Sun does not. The reason is founded in the fact that the Moon shines only by reflected sunlight. When the Moon is closer to the Sun than the Earth, only part of it appears to be lit - resulting in a familiar crescent-shaped phase.

At the Shadow s Edge
25.11.2021

Shaped like a cone tapering into space, the Earth's dark central shadow or umbra has a circular cross-section. It's wider than the Moon at the distance of the Moon's orbit though. But during the lunar eclipse of November 18/19, part of the Moon remained just outside the umbral shadow.

Moonset from Taiwan
14.08.2013

It took three worlds to create this simple image. The first world was the Earth, which was quite prominent. The dividing line running horizontally below the middle separates sea from sky. On this part of the Earth, it was almost nighttime. The second world was the Moon, which was almost invisible.

Bailys Beads near Solar Eclipse Totality
11.11.2012

Just before the Sun blacks out, something strange occurs. As the Moon moves to completely cover the Sun in a total solar eclipse -- like the one set to occur over parts of Australia on Tuesday -- beads of bright sunlight stream around the edge of the Moon.

Ithaca Chasma: The Great Rift on Saturns Tethys
24.06.2008

What created the Great Rift on Saturn's moon Tethys? No one is sure. More formally named Ithaca Chasma, the long canyon running across the right of the above image extends about 2,000 kilometers long and spreads as much as 100 kilometers wide.

APOD: 2025 March 4 Б A Quadruple Alignment over Italy
4.03.2025

Why does this Moon look so unusual? A key reason is its vivid red color. The color is caused by the deflection of blue light by Earth's atmosphere -- the same reason that the daytime sky appears blue. The Moon also appears unusually distorted.

November s Lunar Eclipse
7.11.2003

The Moon slides through the Earth's shadow this Saturday night / Sunday morning (November 8/9) giving skygazers in the Americas, Europe, Africa, and western Asia a chance to enjoy a total lunar eclipse. As lunar eclipses go, this will be a brief one though, with the total phase lasting only about 25 minutes.

Moonquakes Surprisingly Common
27.03.2006

Why are there so many moonquakes? A recent reanalysis of seismometers left on the moon by the Apollo moon landings has revealed a surprising number of moonquakes occurring within 30 kilometers of the surface. In fact, 28 moonquakes were detected in data recorded between 1972 and 1977.