Noctilucent Clouds Over Germany
24.06.2009

Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above.

Moonrise Through Mauna Keas Shadow
4.12.2010

How can the Moon rise through a mountain? It cannot -- what was photographed here is a moonrise through the shadow of a large volcano. The volcano is Mauna Kea, Hawai'i, USA, a frequent spot for spectacular photographs since it is arguably the premier observing location on planet Earth.

A Cliff Looming on Comet 67P
19.05.2015

What that looming behind this gravel-strewn hill on Comet ChuryumovGerasimenko? A jagged cliff. The unusual double-lobed nucleus of Comet 67P/ChuryumovGerasimenko lends itself to unusual and dramatic vistas, another of which has been captured by the Rosetta spacecraft that arrived at the comet last September.

Aurora over Clouds
23.11.2015

Auroras usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact the Earth's magnetosphere, from which charged particles spiral along the Earth's magnetic field to strike atoms and molecules high in the Earth's atmosphere.

The Milky Way Over the Arizona Toadstools
22.02.2015

Which is older -- the rocks you see on the ground or the light you see from the sky? Usually its the rocks that are older, with their origin sentiments deposited well before light left any of the stars or nebulas you see in the sky.

A Rare Annular Venusian Solar Eclipse
15.06.2004

An unusual type of solar eclipse occurred last week. Usually it is the Earth's Moon that eclipses the Sun. Last week, for the first time in over 100 years, the planet Venus took a turn.

A Twisted Meteor Train
1.02.2005

Did this meteor leave a twisting path? Evidently. Meteor trains that twist noticeably are rare - and even more rarely photographed - but have been noted before. The underlying reason for unusual meteors trains is that many meteors are markedly non-spherical in shape and non-uniform in composition.

Stars, Meteors, and a Comet in Taurus
6.01.2019

This was an unusual night to look in the direction of the Bull. The constellation Taurus is always well known for hosting two bright star clusters -- the Pleaides, visible on the right, and the comparatively diffuse Hyades, visible on the left.

Weak Lensing Distorts the Universe
29.03.2008

Is the distant universe really what it appears to be? Astronomers hope not. Intervening dark matter, which is normally invisible, might show its presence by distorting images originating in the distant universe, much the way an old window distorts images originating on the other side.

Asperitas Clouds Over New Zealand
18.08.2018

What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Formally recognized as a distinct cloud type only last year, Asperitas clouds can be stunning in appearance, unusual in occurrence, and are relatively unstudied.