The Mileage of Light
28.05.2011

If you're driving down a dark road on a starry night, you might want to check the odometer. Earlier this month, when traveling astronomer Dennis Mammana did he was greeted with the significant mileage reading of 186,282 miles. That's the number of miles light travels in one second.

Cave with Aurora Skylight
22.07.2014

Yes, but have you ever seen aurora from a cave? To capture this fascinating juxtaposition between below and above, astrophotographer Bjargmundsson spent much of a night alone in the kilometer-long RaufarhСlshellir lava cave in Iceland during late March. There, he took separate images of three parts of the cave using a strobe for illumination.

The Pleiades Star Cluster
6.05.2001

It is the most famous star cluster on the sky. The Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

The Annotated Galactic Center
28.12.2001

The sky toward the center of our Galaxy is filled with a wide variety of celestial wonders. Many are easily visible with binoculars. Constellations near the galactic center include Sagittarius, Libra, Scorpius, Scutum, and Ophiuchus. Nebulae include Messier Objects M8, M16, M17, M20 and the Pipe Nebula.

Touran Sunrise
22.03.2007

Clouds covered the eastern horizon on Monday, when the Sun rose over the expansive Touran Wildlife Reserve in northeastern Iran. Of course, on that day the Moon rose with the Sun, creating a widely enjoyed partial solar eclipse.

December Sunrise, Cape Sounion
22.12.2009

The Sun is a moving target. Its annual motion through planet Earth's sky tracks north and south, from solstice to solstice, as the seasons change. On December 21st, the solstice marking the first...

As Above, So Below
3.12.2011

A single, long exposure captured these star trails above a remarkably colorful sea of clouds. As seen from Medvednica mountain, the surrounding peaks and lights illuminating the clouds from below are north of Zagreb, Croatia.

Comet PANSTARRS Just After Sunset
18.03.2013

Have you seen the comet? As Comet PANSTARRS fades, careful observers -- even with unaided eyes -- should still be able to find the shedding ice ball on the western horizon just after sunset. Pictured above, Comet PANSTARRS (C/2011 L4) was pointed out from a hilltop last week on First Encounter Beach in Massachusetts, USA.

Sunspot at Sunset
13.07.2013

Reddened rays of the setting Sun flooded the skies over Cedar Creek Lake, southeast of Dallas, Texas, planet Earth on July 6th. And while sunsets may be the most watched celestial event, this one even offered something extra.

Full Moon and Boston Light
12.07.2017

This well-planned telephoto timelapse captures July's Full Moon rise across outer Boston Harbor, Massachusetts, planet Earth. In the foreground, the historic terrestrial beacon is known as Boston Light. July's Full Moon...