The Not So Quiet Sun
6.08.2010

After a long solar minimum, the Sun is no longer so quiet. On August 1, this extreme ultraviolet snapshot of the Sun from the Solar Dynanimcs Observatory captured a complex burst of activity playing across the Sun's northern hemisphere.

Moonbow and Rainbows Over Patagonia
10.08.2009

Have you ever seen a moonbow? Just as rainbows are lit by the Sun, moonbows are lit by the Moon. Since the Sun is so much brighter than the Moon, sunlit rainbows are much brighter and more commonly seen than moonbows.

The Swift View of Comet Lulin
21.02.2009

Now growing brighter, Comet Lulin is headed for its closest approach to planet Earth early next week. But the comet's greenish glow, familiar to earthbound skygazers, is replaced by false colors in this premier view from the orbiting Swift satellite.

Sundogs over the VLA
23.08.1999

What if you woke up one morning and saw more than one Sun in the sky? Most probably, you would be seeing sundogs, extra-images of the Sun created by falling ice-crystals in the Earth's atmosphere. As water freezes in the atmosphere, small, flat, six-sided, ice crystals might be formed.

APOD: 2026 August 3 Б Vaporizing Meteor Photobombs the Lacerta Nebula
3.08.2026

What's happening to this meteor? This bright meteor streak appeared and disappeared quickly during a long exposure of the Great Lacerta Nebula, seen faintly in red toward the center of the image.

Halley s Nucleus: An Orbiting Iceberg
5.08.2000

What does a comet nucleus look like? Formed from the primordial stuff of the solar system, it is thought to resemble a very dirty iceberg. But for active comets, telescopic images only reveal the surrounding cloud of gas and dust, the comet's coma, and the characteristic cometary tails.

A Sun Halo Beyond Stockholm
10.01.2011

What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a large lens. In the above case, however, there are actually millions of lenses: ice crystals. As water freezes in the upper atmosphere, small, flat, six-sided, ice crystals might be formed.

APOD: 2026 August 22 Б Mostly Perseids
22.08.2026

Recorded the night of August 12-13, images from four dedicated meteor-monitoring cameras at an astronomical observatory in Czechia were aligned and combined to create this all-night, all-sky view. On that night, the total count came to 1,706 meteors.

Fibrils Flower on the Sun
16.02.2015

When does the Sun look like a flower? In a specific color of red light emitted by hydrogen, as featured here, some regions of the solar chromosphere may resemble a rose. The color-inverted image was taken in 2014 October and shows active solar region 2177.

Comet C 2002 T7 (LINEAR)
22.04.2004

Discovered by the the Lincoln Near Earth Asteroid Research (LINEAR) project in October of 2002, comet C/2002 T7 is now visiting the inner solar system, making its closest approach (see animation by L. Koehn) to the Sun tomorrow, April 23rd.