Red Aurora Over Australia
28.01.2017

Why would the sky glow red? Aurora. A solar storm in 2012, emanating mostly from active sunspot region 1402, showered particles on the Earth that excited oxygen atoms high in the Earth's atmosphere. As the excited element's electrons fell back to their ground state, they emitted a red glow.

Red Aurora Over Australia
1.02.2012

Why would the sky glow red? Aurora. Last week's solar storms, emanating mostly from active sunspot region 1402, showered particles on the Earth that excited oxygen atoms high in the Earth's atmosphere. As the excited element's electrons fell back to their ground state, they emitted a red glow.

The Expanding Echoes of Supernova 1987A
23.02.2019

Can you find supernova 1987A? It isn't hard -- it occurred at the center of the expanding bullseye pattern. Although this stellar detonation was first seen in 1987, light from SN 1987A continued to bounce off clumps of interstellar dust and be reflected to us even many years later.

Mars, Pleiades, and Andromeda over Stone Lions
12.10.2020

Three very different -- and very famous -- objects were all captured in a single frame last month. On the upper left is the bright blue Pleiades, perhaps the most famous cluster of stars on the night sky. The Pleiades (M45) is about 450 light years away and easily found a few degrees from Orion.

Supernova 1987a Fireball Resolved
23.01.1997

Ten years ago the most notable supernova of modern times was observed. In February 1987, light reached Earth from a star which exploded in the nearby Large Magellanic Cloud galaxy. Supernova 1987a remains the closest supernova since the invention of the telescope.

30 Doradus Across the Spectrum
23.12.1997

30 Doradus is lit up like a Christmas tree. Shining in light across the electromagnetic spectrum, 30 Doradus glows because of all the energetic processes that go on there. A distinctive region visible...

Eclipsed Moon in the Milky Way
17.06.2011

On June 15, the totally eclipsed Moon was very dark, with the Moon itself positioned on the sky toward the center of our Milky Way Galaxy. This simple panorama captures totality from northern Iran in 8 consecutive exposures each 40 seconds long.

Sky Delights Over Sweden
15.04.2008

This night was a sky enthusiast's delight. While relaxing in Sweden last week, many a cosmic wonder was captured with a single snapshot. They are described here from near to far. In the foreground are nearby trees and more distant snow covered mountains.

A Volcano of Fire under a Milky Way of Stars
26.05.2019

Sometimes it's hard to decide which is more impressive -- the land or the sky. On the land of the featured image, for example, the Volcano of Fire (VolcАn de Fuego) is seen erupting topped by red-hot, wind-blown ash and with streams of glowing lava running down its side.

X Ray Milky Way
9.01.2002

If you had x-ray vision, the center regions of our galaxy would not be hidden from view by immense cosmic dust clouds opaque to visible light. Instead, the Milky Way toward Sagittarius might look something like this stunning mosaic of images from the orbiting Chandra Observatory.