Regulus Occulted
2.08.1999

On May 21, viewed from the continental US, a star winked out as it passed behind the dark limb of the first-quarter Moon. The star, Regulus, is hotter than the sun, about 69 light-years distant, and shines in Earth's skies as the brightest star in the constellation Leo, the Lion.

Eclipsed Moonlight
22.02.2008

Moon watchers blessed with clear skies over the Americas, Europe, Africa and western Asia enjoyed a total lunar eclipse this week. Catching eclipsed moonlight, astroimager Jerry Lodriguss offers this view of the inspiring celestial...

Ice at the Lunar South Pole
4.12.1996

Ice on the Moon? The prospecting Clementine spacecraft may well have discovered it. In 1994, Clementine spent 70 days in lunar orbit mapping the Moon's surface. Shown above is a dramatically detailed composite view centered on the Lunar South Pole - constructed from 1500 Clementine images.

Sun Block
18.08.1999

During a total solar eclipse, Earth's moon blocks the sun - almost exactly. While the sun is about 400 times wider than the moon, it is also about 400 times farther away and each appears to be half a degree or so in diameter.

Moonquakes Surprisingly Common
10.10.2010

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.

APOD: 2025 September 1 Б Callisto: Dirty Battered Iceball
1.09.2025

Its surface is the most densely cratered in the Solar System -- but what's inside? Jupiter's moon Callisto is a battered ball of dirty ice that is larger than the planet Mercury.

Embraced by Sunlight
3.02.2022

Even though Venus (left) was the brightest planet in the sky it was less than 1/30th the apparent size of the Moon on January 29. But as both rose before the Sun they shared a crescent phase.

A Lunar Eclipse on Solstice Day
20.12.2010

Sometime after sunset tonight, the Moon will go dark. This total lunar eclipse, where the entire Moon is engulfed in the shadow of the Earth, will be visible from all of North America, while the partial phase of this eclipse will be visible throughout much of the rest of the world.

Mimas, Crater, and Mountain
11.01.2017

Mimas is an icy, crater-pocked moon of Saturn a mere 400 kilometers (250 miles) in diameter. Its largest crater Herschel is nearly 140 kilometers wide. About a third the diameter of Mimas itself, Herschel crater gives the small moon an ominous appearance, especially for scifi fans of the Death Star battlestation of Star Wars fame.

APOD: 2025 March 30 Б A Partial Solar Eclipse over Iceland
30.03.2025

What if the Sun and Moon rose together? That happened yesterday over some northern parts of planet Earth as a partial solar eclipse occurred shortly after sunrise. Regions that experienced the Moon blocking part of the Sun included northeastern parts of North America and northwestern parts of Europe, Asia, and Africa.