A Martian Halloween
31.10.2005

From sunset to sunrise, an unusually bright yellowish orb will hang in the sky this Halloween: Mars. Yesterday, Earth passed Mars as they orbited the Sun, bringing Mars closer than it will be for the next thirteen years. Tonight though, Mars will be nearly as bright as last night, a beacon of extraterrestrial spookiness.

Regulus Occulted
2.08.1999

On May 21, viewed from the continental US, a star winked out as it passed behind the dark limb of the first-quarter Moon. The star, Regulus, is hotter than the sun, about 69 light-years distant, and shines in Earth's skies as the brightest star in the constellation Leo, the Lion.

Aurora, Stars, Meteor, Lake, Alaska
9.10.2007

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 aurora flap high above you, brilliant stars shine far in the distance, and, for a brief moment, a bright meteor streaks by.

Simeis 147: Supernova Remnant from Palomar
29.11.2005

It's easy to get lost following the intricate filaments in this detailed image of faint supernova remnant Simeis 147. Seen towards the constellation Taurus it covers nearly 3 degrees (6 full moons) on the sky corresponding to a width of 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years.

Messier Marathon
27.05.2011

In this action scene, red night vision lights, green laser pointers, tripods and telescopes in faint silhouette surround intrepid sky gazers embarked on the 10th annual Iran Messier Marathon. Completing the marathon requires viewing all 110 objects in 18th century French astronomer Charles Messier's catalog in one glorious dusk-to-dawn observing run.

The Light of Stars
8.05.2012

What's moving? Time lapse videos of the sky can be quite spectacular when they last long enough for stars, planets, aurora, and clouds to appear to move in just a few seconds. Pictured...

Comet LINEAR Extends
10.07.2000

Comet LINEAR's tail appears to be extending. Many sky watchers are closely following Comet C/1999 S4 LINEAR and wondering if it will develop an impressive tail or become visible to the naked eye later this month.

Star Trails Over Vienna
14.07.2005

As the Earth spins on its axis, the sky seems to rotate around us. This motion, called diurnal motion, produces the beautiful concentric trails traced by stars during time exposures. In the middle...

Eclipse at Moonset
9.10.2014

The Pacific Ocean and Chilean coast lie below this sea of clouds. Seen through the subtle colors of the predawn sky a lunar eclipse is in progress above, the partially eclipsed Moon growing dark.

ELT and the Milky Way
16.03.2024

The southern winter Milky Way sprawls across this night skyscape. Looking due south, the webcam view was recorded near local midnight on March 11 in dry, dark skies over the central Chilean Atacama desert.