Moonrise and Mountain Shadow
13.03.2020

What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is 3.14 radians (aka 180 degrees) from the Sun in ecliptic longitude.

Springtime on Mars
22.04.2003

Vast canyons, towering volcanoes, sprawling fields of ice, deep craters, and high clouds can all be seen in this image of the Solar System's fourth planet: Mars. The orbiting robot Mars Global Surveyor spacecraft took the above mosaic of images as springtime dawned in Northern Mars in 2002 May.

Enceladus Close Up
16.03.2005

The surface of Enceladus is as white as fresh snow. Still, an impressive variety of terrain is revealed in this contrast enhanced image. At a resolution of about 30 meters per pixel, the close-up view spans over 20 kilometers - recorded during the touring Cassini spacecraft's March flyby of the icy Saturnian moon.

APOD: 2025 May 20 Б Milky Way over Maunakea
19.05.2025

Have you ever seen the band of our Milky Way Galaxy? In a clear sky from a dark location at the right time, a faint band of light becomes visible across the sky. Soon after your eyes become dark adapted, you might spot the band for the first time. It may then become obvious.

APOD: 2023 August 15 Б A Triply Glowing Night Sky over Iceland
14.08.2023

The Sun is not the quiet place it seems. It expels an unsteady stream of energetic electrons and protons known as the solar wind. These charged particles deform the Earth's magnetosphere, change paths...

A Hole in Mars
9.03.2014

What created this unusual hole in Mars? The hole was discovered by chance in 2011 on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars.

Galileo Views Io Eruption
15.08.1996

Io's surface is active. Geyser-like eruptions from volcanoes on this Jovian moon were seen by both Voyager spacecraft in 1979 and were also spotted this year in late June by Galileo's camera from a distance of about 600,000 miles.

The Helix Nebula from CFHT
23.11.2020

Will our Sun look like this one day? The Helix Nebula is one of brightest and closest examples of a planetary nebula, a gas cloud created at the end of the life of a Sun-like star.

A Furious Sky over Mount Shasta
27.09.2022

Is the sky angry with Mount Shasta? According to some ancient legends, the spirits of above and below worlds fight there, sometimes quite actively during eruptions of this enormous volcano in California, USA. Such drama can well be imagined in this deep sky image taken in late June.

Mars and a Colorful Lunar Fog Bow
1.02.2010

Even from the top of a volcanic crater, this vista was unusual. For one reason, Mars was dazzlingly bright two weeks ago, when this picture was taken, as it was nearing its brightest time of the entire year. Mars, on the far upper left, is the brightest object in the above picture.