APOD: 2004 August 28- M17: A Hubble Close-Up
28.08.2004

Sculpted by stellar winds and radiation, these fantastic, undulating shapes lie within the stellar nursery known as M17, the Omega Nebula, some 5,500 light-years away in the nebula-rich constellation Sagittarius. The lumpy features...

Messier 88
30.01.2010

Charles Messier described the 88th entry in his 18th century catalog of Nebulae and Star Clusters as a spiral nebula without stars. Of course the gorgeous M88 is now understood to be a galaxy full of stars, gas, and dust, not unlike our own Milky Way.

Ghosts and Star Trails
31.10.2015

Don't be scared. Stars won't fall from the sky and ghosts won't really haunt your neighborhood tonight. But it looks like they might be doing just that in this eerie picture of an eccentric old abandoned house in moonlight.

Perseid Meteors over Turkey
1.08.2017

The Perseid Meteor Shower, usually the best meteor shower of the year, will peak late next week. A person watching a clear sky from a dark location might see a bright meteor every minute.

Retrograde Mars
11.05.2008

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Spiral Sunspot
4.02.1999

Spiral galaxies abound in the universe, but spiral sunspots are definitely an unusual twist. This distinctive spiral-shaped sunspot caught the attention of National Solar Observatory astronomers and was photographed on February 19, 1982 with the Vacuum Solar Telescope on Kitt Peak.

Comet Lulin and Distant Galaxies
7.03.2009

Now fading in our night sky, Comet Lulin has provided some lovely cosmic vistas. Moving rapidly against the background of stars, Lulin briefly posed with the likes of Saturn, and Regulus (Alpha Leo). But here it is seen against a field of distant galaxies.

Higgs Boson Explained by Cartoon
1.05.2012

What is all this fuss about the Higgs boson? The physics community is abuzz that a fundamental particle expected by the largely successful Standard Model of particle physics may be soon be found by the huge Large Hadron Collider (LHC) at CERN in Europe.

High Noon Analemma Over Azerbaijan
14.10.2013

Is the Sun always straight up at noontime? No. For example, the Sun never appears directly overhead from locations well north or south of the Earth's equator. Conversely, there is always a place on Earth where the Sun will appear at zenith at noon -- for example on the equator during an equinox.

Sand Dunes Thawing on Mars
24.09.2019

What are these strange shapes on Mars? Defrosting sand dunes. As spring dawned on the Northern Hemisphere of Mars, dunes of sand near the pole, as pictured here in late May by ESA's ExoMars Trace Gas Orbiter, began to thaw.