The Bay of Rainbows
12.02.2026

Dark, smooth regions that cover the Moon's familiar face are called by Latin names for oceans and seas. That naming convention is historical, though it may seem a little ironic to denizens...

A Lunar Eclipse Mosaic
6.05.2004

From start to finish, this impressive digital mosaic covers May 4th's total eclipse of the Moon. Astronomer Anthony Ayiomamitis reports that the eclipse viewing was wonderful from Greece, where skies cleared shortly before the celestial show began.

Celestial Alignment over Sicilian Shore
4.03.2019

This was a sunrise to remember. About a month ago, just before the dawn of the Sun, an impressive alignment of celestial objects was on display to the east. Pictured, brightest and closest to the horizon, is the Moon.

Io in True Color
20.09.1999

The strangest moon in the Solar System is bright yellow. This recently released picture, showing Io's true colors, was taken in July by the Galileo spacecraft currently orbiting Jupiter. Io's colors derive from sulfur and molten silicate rock. The unusual surface of Io is kept very young by its system of active volcanoes.

Opposite the Setting Sun
3.05.2018

On April 30, a Full Moon rose opposite the setting Sun. Its yellowish moonglow silhouettes a low tree-lined ridge along Lewis Mountain in this northeastern Alabama skyscape. Sharing the telephoto field-of-view opposite the Sun are Earth's grey shadow, the pinkish Belt of Venus, and bright planet Jupiter.

Views from Cassini at Saturn
18.06.2017

What has the Cassini orbiter seen at Saturn? The featured music video shows some of the early highlights. In the first time-lapse sequence (00:07), a vertical line appears that is really Saturn's thin rings seen nearly edge-on. Soon some of Saturn's moon shoot past.

Aurora Over Yellowknife
22.09.2009

Sometimes, after your eyes adapt to the dark, a spectacular sky appears. In this case, a picturesque lake lies in front of you, beautiful green auroras flap high above you, brilliant stars shine far in the distance, and a brilliant moon shines just ahead of you.

A Colorful Lunar Corona
15.06.2015

What are those colorful rings around the Moon? A corona. Rings like this will sometimes appear when the Moon is seen through thin clouds. The effect is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in an intervening but mostly-transparent cloud.

Tololo Totality
15.03.2025

On March 14 the Moon was Full. In an appropriate celebration of Pi day, that put the Moon 3.14 radians (180 degrees) in ecliptic longitude from the Sun in planet Earth's sky.

The Largest Impact Crater
6.09.1996

What is the largest known impact crater in the Solar System? Over 1300 miles across, the South Pole-Aitken Basin on the farside of Earth's Moon holds that distinction. Circled above in a false color mosaic of Clementine images it was caused when an asteroid or comet sized object crashed