Moons and Bright Mars
1.08.2003

In this serene view, the moons of Earth along with the bright planet Mars shine above the city of Turku near the southwestern tip of Finland. Of course Earth's large natural satellite, the Moon, at a distance of 400,000 kilometers, is by far the brightest object in this sky.

An Annular Solar Eclipse at High Resolution
5.10.2005

On Monday, part of the Sun went missing. The missing piece was no cause for concern -- the Moon was only momentarily in the way. The event was not a total eclipse of the Sun for any Earth-bound sky enthusiast but rather, at best, an annular eclipse, where the Moon blocked most of the Sun.

Comet Lulin and Distant Galaxies
6.03.2009

Now fading in our night sky, Comet Lulin has provided some lovely cosmic vistas. Moving rapidly against the background of stars, Lulin briefly posed with the likes of Saturn, and Regulus (Alpha Leo). But here it is seen against a field of distant galaxies.

Golden Gate Sunset: Green Flash
1.12.2015

The setting is San Francisco Bay, the time is sunset, and the bridge is the Golden Gate. What you are about to see is an unexpected double sunset ending with a rare green flash.

APOD: 2025 April 30 Б A Happy Sky over Bufa Hill in Mexico
29.04.2025

Sometimes, the sky itself seems to smile. A few days ago, visible over much of the world, an unusual superposition of our Moon with the planets Venus and Saturn created just such an iconic facial expression.

Io: The Prometheus Plume
18.08.1997

Two sulfurous eruptions are visible on Jupiter's volcanic moon Io in this color composite Galileo image. On the left, over Io's limb, a new bluish plume rises about 86 miles above the surface of a volcanic caldera known as Pillan Patera.

Sparkling Star May Indicate Galactic Composition
24.06.1998

If a star in this photograph twinkled slightly, would anyone notice? Would anyone care? Astronomers with the MACHO Collaboration noticed one such twinkle just last week, and many members of the astronomical community now care.

A Planet For Gliese 876
26.06.1998

Centered in this unremarkable, 1/4 degree wide patch of sky in the constellation Aquarius is the star Gliese 876. Gliese 876 is smaller than the Sun, only about 1/3 as massive, and too faint to be seen without a telescope. But it is known to be one of the nearest stars, only 15 light-years distant.

The Perseus Cluster of Galaxies
29.12.2005

Here is one of the largest objects that anyone will ever see on the sky. Each of these fuzzy blobs is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies. The cluster is seen through a foreground of faint stars in our own Milky Way Galaxy.

Star Factory Messier 17
10.08.2007

Sculpted by stellar winds and radiation, the star factory known as Messier 17 lies some 5,500 light-years away in the nebula-rich constellation Sagittarius. At that distance, this 30 arcminute field of view spans almost 50 light-years.