The Lunar X
10.12.2016

The striking X appearing in this lunarscape is easily visible in binoculars or a small telescope. Yet, not too many have seen it. The catch is this lunar X is fleeting, only apparent in the hours before the Moon's first quarter phase.

A Phoenix Aurora over Iceland
3.01.2021

All of the other aurora watchers had gone home. By 3:30 am in Iceland, on a quiet September night, much of that night's auroras had died down. Suddenly, unexpectedly, a new burst of particles streamed down from space, lighting up the Earth's atmosphere once again.

Saturn and Six Moons
6.07.2021

How many moons does Saturn have? So far 82 have been confirmed, the smallest being only a fraction of a kilometer across. Six of its largest satellites can be seen here in a composite...

Orion Pines
16.04.2022

Taken with a camera fixed to a tripod, many short exposures were aligned with the stars to unveil this beautiful, dark night sky. Captured near the rural village of Albany`a at the northeastern corner of Spain, the three stars of Orion's belt stretch across top center in the starry frame.

APOD: 2025 June 24 Б In the Center of Spiral Galaxy M61
24.06.2025

Is there a spiral galaxy in the center of this spiral galaxy? Sort of. Image data from the Hubble Space Telescope, the European Southern Observatory, and smaller telescopes on planet Earth are combined in this detailed portrait of face-on spiral galaxy Messier 61 (M61) and its bright center.

Jupiter s Brain
1.02.2001

Gas giant Jupiter is the solar system's largest world with about 320 times the mass of planet Earth. Famous for its Great Red Spot, Jupiter is also known for its regular, equatorial cloud bands, visible in very modest sized telescopes.

The Milky Way Behind an Eclipsed Moon
3.06.2003

What's behind the Moon? Each month, our Moon passes in front of -- and outshines -- many an interesting star field. Exceptions occur during a new Moon and during a total eclipse. In the background...

How to Search for Aliens
17.05.1999

"Mom, can I use our computer to search for aliens?" Last week, the SETI@home project released free software that enables many home computers to search for signals from intelligent extra-terrestrials. These signals may have already been detected by the huge Arecibo radio telescope

NGC 1 and NGC 2
19.08.2005

Beautiful nebulae, clusters, and galaxies that grace planet Earth's night sky are often known by their New General Catalog designation or NGC number. That classic listing was compiled by John Louis Emil Dreyer, remarkable director of the Armagh Observatory from 1882 to 1916.

Messier Craters in Stereo
8.06.2013

Many bright nebulae and star clusters in planet Earth's sky are associated with the name of astronomer Charles Messier, from his famous 18th century catalog. His name is also given to these two large and remarkable craters on the Moon.