Frosty Mountains on Mars
30.07.2003

What causes the unusual white color on some Martian mountains? The answer can be guessed by noticing that the bright areas disappear as springtime takes hold in the south of Mars: dry ice. Unlike water ice, dry carbon dioxide ice sublimates directly to gas from its frozen state.

Beta Pictoris Revisited
28.11.1997

In the early 1980s, Beta Pictoris became one of the most important stars in the sky. Satellite and ground-based telescopic observations revealed the presence of a surrounding outer disk of material and an inner "clear" zone about the size of our solar system - strong evidence for the formation of planets.

An Unexplored Nebula
29.09.2005

The combined light of the stars of the Milky Way are reflected by this cosmic dust cloud that soars some 300 light-years above the plane of our Galaxy. Dubbed the Angel Nebula by astronomer...

Circum axial Leaf Trails
19.05.2007

Are photographs of star trails really evidence of the Earth's rotation about its axis? Yes they are, and science journalist Trudy E. Bell discovered that there is a simple way to demonstrate this, if you have the stomach for it.

Sunset at the Portara
20.03.2009

Today, the Sun crosses the celestial equator heading north at 11:44 UT. Known as an equinox, this astronomical event marks the first day of spring in the northern hemisphere and autumn in the south. It also marks the beginning of Norouz, the Persian (Iranian) new year. Equinox means equal night.

Kona Galaxy Garden
18.01.2011

How does your galaxy grow? Quite contrary to a typical galaxy, this one needs water to flourish. Pictured above as it appears at the Paleaku Peace Gardens Sanctuary in Kona, Hawaii, USA, a meticulously planned garden spanning about 30 meters provides a relatively accurate map of our Milky Way Galaxy.

Little Planet Lovejoy
11.01.2012

Once a bright apparition in the southern hemisphere dawn Comet Lovejoy is fading, but its long tail still stretches across skies near the south celestial pole. Captured on the morning of December 30th, the comet appears near edge of this little planet as well.

The Bubble and M52
8.10.2013

To the eye, this cosmic composition nicely balances the Bubble Nebula at the lower left with open star cluster M52 above it and to the right. The pair would be lopsided on other scales, though.

Sprite Lightning in Slow Motion
13.10.2014

What causes sprite lightning? Mysterious bursts of light in the sky that momentarily resemble gigantic jellyfish have been recorded for over 25 years, but their root cause remains unknown. Some thunderstorms have them -- most don't. Recently, however, high speed videos are better detailing how sprites actually develop.

Gamma ray Rain from 3C 279
22.07.2015

If gamma-rays were raindrops a flare from a supermassive black hole might look like this. Not so gently falling on the Fermi Gamma-ray Space Telescope from June 14 to June 16 the gamma-ray photons, with energies up to 50 billion electron volts, originated in active galaxy 3C 279 some 5 billion light-years away.