11 Hour Star Trails
15.09.2006

Fix your camera to a tripod, lock the shutter open, and you can make an image of star trails - graceful concentric arcs traced by the stars as planet Earth rotates on its axis. Of course, the length of the star trails will depend on the exposure time.

Meteor Over Crater Lake
25.04.2012

Did you see it? One of the more common questions during a meteor shower occurs because the time it takes for a meteor to flash is typically less than the time it takes for a head to turn.

Orion: Belt, Flame, and Horsehead
4.06.2017

What surrounds the famous belt stars of Orion? A deep exposure shows everything from dark nebula to star clusters, all embedded in an extended patch of gaseous wisps in the greater Orion Molecular Cloud Complex.

APOD: 2025 September 25 Б Saturn Opposite the Sun
25.09.2025

This year Saturn was at opposition on September 21, opposite the Sun in planet Earth's sky. At its closest to Earth, Saturn was also at its brightest of the year, rising as the Sun set and shining above the horizon all night long among the fainter stars of the constellation Pisces.

The Complete Galactic Plane: Up and Down
13.03.2018

Is it possible to capture the entire plane of our galaxy in a single image? Yes, but not in one exposure -- and it took some planning to do it in two. The top part of the featured image is the night sky above Lebanon, north of the equator, taken in 2017 June.

The 220 Mirrors of CRTF
4.10.1999

Even the largest of modern optical telescopes are small when compared with the light gathering power of the Central Receiver Test Facility (CRTF) located in New Mexico, USA. CRTF has 220 mirrors each over 7-meters in diameter all focused on a single tower.

Cloud, Clusters and Comet Siding Spring
4.09.2014

On October 19th, a good place to watch Comet Siding Spring will be from Mars. Then, this inbound visitor (C/2013 A1) to the inner solar system, discovered in January 2013 by Robert McNaught at Australia's Siding Spring Observatory, will pass within 132,000 kilometers of the Red Planet.

Polaris and the Trail of Comet ZTF
3.02.2023

Stars trace concentric arcs around the North Celestial Pole in this three hour long night sky composite, recorded with a digital camera fixed to a tripod on January 31, near цger, Lleida, Spain. On that date Comet C/2022 E3 (ZTF) was near its northernmost declination in planet Earth's sky.

A Late Leonid from a Sparse Shower
25.11.2003

The 2003 Leonids Meteor Shower contained relatively few meteors. As expected and unlike the last few years, the Earth just did not pass through any dense particle streams left over by the Sun-orbiting Comet Tempel-Tuttle.

Mars Saturn Conjunction
9.04.2022

Fainter stars in the zodiacal constellation Capricornus are scattered near the plane of the ecliptic in this field of view. The two brightest ones at center aren't stars at all though, but the planets Mars and Saturn.