Aurora Over Winnipeg
5.11.2001

What's happening above that city? The city is Winnipeg, Canada, and the phenomenon is aurora. These past few months have been active ones for our Sun, producing several coronal mass ejections (CMEs) of particles that have swept past our Earth and caused many spectacular auroras.

X-Ray Earth
30.12.1996

The Earth glows in many kinds of light, including the energetic X-ray band. Actually, the Earth itself does not glow - only aurora produced high in the Earth's atmosphere. Above is the first picture of the Earth in X-rays, taken in March with the orbiting Polar satellite. Bright X-ray emission is shown in red.

Star Cluster Messier 67
9.08.2007

Gathered at the center of this sharp skyview are the stars of Messier 67, one of the oldest known open star clusters. In fact, though open star clusters are usually much younger, the stars...

A Floral Aurora Corona
28.07.2009

Few auroras show this level of detail. Above, a standard digital camera captured a particularly active and colorful auroral corona that occurred last week above Alberta, Canada. With a shape reminiscent of a flower, the spectacular aurora had an unusually high degree of detail.

Diamonds in a Cloudy Sky
8.08.2009

Cloudy skies over Wuhan, China hid the delicate solar corona during July's total eclipse of the Sun. Still, the Moon's silhouette was highlighted by these glistening diamonds as the total eclipse phase ended.

A Full Circle Rainbow over Norway
27.12.2022

Have you ever seen an entire rainbow? From the ground, typically, only the top portion of a rainbow is visible because directions toward the ground have fewer raindrops. From the air, though, the entire 360-degree circle of a rainbow is more commonly visible.

Meteor Borealis
16.08.2024

A single exposure made with a camera pointed almost due north on August 12 recorded this bright Perseid meteor in the night sky west of Halifax, Nova Scotia, Canada. The meteor's incandescent trace is fleeting.

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...

APOD: 2006 September 27- Earth from Saturn
27.09.2006

What's that pale blue dot in this image taken from Saturn? Earth. The robotic Cassini spacecraft looked back toward its old home world earlier this month as it orbited Saturn. Using Saturn itself to block the bright Sun, Cassini imaged a faint dot on the right of the above photograph.