Geometers Playground Over Wyoming
6.06.2011

If you travel several kilometers off a main highway through Wyoming, you may see an unusual sight. In particular, near Buford, Wyoming, USA, you could run across the geometric Ames Monument, visible on the right, built to commemorate the financiers of a historic transcontinental railroad across North America.

The Sombrero Galaxy from Hubble
26.07.2015

Why does the Sombrero Galaxy look like a hat? Reasons include the Sombrero's unusually large and extended central bulge of stars, and dark prominent dust lanes that appear in a disk that we see nearly edge-on. Billions of old stars cause the diffuse glow of the extended central bulge.

Geminid Meteors over Xinglong Observatory
23.12.2015

Where do Geminid meteors come from? In terms of location on the sky, as the featured image composite beautifully demonstrates, the sand-sized bits of rock that create the streaks of the Geminid Meteor Shower appear to flow out from the constellation of Gemini.

Penumbral Lunar Eclipse
12.10.2016

Does this Moon look a little different to you? Although shown in spectacular detail, the full face of Earth's most familiar satellite appears slightly darker than usual, in particular on the upper left, because it is undergoing a penumbral lunar eclipse.

Active Prominences on a Quiet Sun
20.08.2018

Why is the Sun so quiet? As the Sun enters into a period of time known as a Solar Minimum, it is, as expected, showing fewer sunspots and active regions than usual. The quietness is somewhat unsettling, though, as so far this year, most days show no sunspots at all.

Dwarf Elliptical Galaxy NGC 205 in the Local Group
23.10.2000

Our Milky Way Galaxy is not alone. It is part of a gathering of about 25 galaxies known as the Local Group. Members include the Great Andromeda Galaxy (M31), M32, M33, the Large Magellanic Cloud, the Small Magellanic Cloud, Dwingeloo 1, several small irregular galaxies, and many dwarf elliptical and dwarf spheroidal galaxies.

Disappearing Clouds in Carina
30.06.2003

This dense cloud of gas and dust is being deleted. Likely, within a few million years, the intense light from bright stars will have boiled it away completely. Stars not yet formed in the molecular cloud's interior will then stop growing.

Cassini Images Density Waves in Saturns Rings
5.07.2004

What causes the patterns in Saturn's rings? The Cassini spacecraft just entering orbit around Saturn has started sending back spectacular images of Saturn's immense ring system in unprecedented detail. The physical cause for many of newly resolved ring structures is not always understood.

Candidates for a Hypernova
20.04.1999

What created these huge explosion remnants? Speculation has been building recently that outbursts even more powerful than well-known supernovae might occur. Dubbed hypernovae, these explosions might result from high-mass stars and liberate perhaps ten times more energy than conventional supernovae.

Reflections on NGC 6188
1.06.2006

NGC 6188 is an interstellar carnival of young blue stars, hot red gas, and cool dark dust. Located 4,000 light years away in the disk of our Galaxy, NGC 6188 is home to the Ara OB1 association, a group of bright young stars whose nucleus forms the open cluster NGC 6193.