Planck Maps the Microwave Background
22.07.2018

What is our universe made of? To help find out, ESA launched the Planck satellite from 2009 to 2013 to map, in unprecedented detail, slight temperature differences on the oldest optical surface known -- the background sky when our universe first became transparent to light.

Hercules Galaxies
27.08.1998

These are galaxies of the Hercules Cluster, an archipelago of "island universes" a mere 650 million light-years distant. This cluster is loaded with gas and dust rich, star forming, spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars.

The Lyman Alpha Forest
26.01.2003

We live in a forest. Strewn throughout the universe are "trees" of hydrogen gas that absorb light from distant objects. These gas clouds leave numerous absorption lines in a distant quasar's spectra, together called the Lyman-alpha forest.

The Gamma Ray Sky
21.03.1998

What if you could "see" gamma rays? If you could, the sky would seem to be filled with a shimmering high-energy glow from the most exotic and mysterious objects in the Universe.

The Lyman Alpha Forest
24.02.1998

We live in a forest. Strewn throughout the universe are "trees" of hydrogen gas that absorb light from distant objects. These gas clouds leave numerous absorption lines in a distant quasar's spectra, together called the Lyman-alpha forest.

I Zwicky 18: The Case of the Aging Galaxy
17.10.2007

How old is this galaxy? The galaxy on the left, I Zwicky 18, was once thought to be one of the youngest galaxies on record since its bright stars indicated an age of only 500 million years.

Globular Cluster M2
11.06.2001

Beneath the south pole of our Milky Way Galaxy lies a ball of over 100,000 stars. M2, the second object on Charles Messier's eighteenth century list of bright diffuse sky objects...

The Hercules Cluster of Galaxies
19.07.2007

These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars.

The Hercules Cluster of Galaxies
16.07.2009

These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars.

The Gamma Ray Sky
22.02.1997

What if you could "see" gamma rays? If you could, the sky would seem to be filled with a shimmering high-energy glow from the most exotic and mysterious objects in the Universe.