A Year of Dark Cosmology
31.12.2001

We live in the exciting time when humanity discovers the nature of our entire universe. During this year, in particular, however, the quest for cosmological understanding appears to have astronomers groping in the dark.

A Year of Resolving Cosmology
31.12.2003

This year, humanity learned that the universe is 13.7 billion years old. Before this year, the universe's age was thought to be about 13 billion years, but really only constrained to be between about 12 billion and 15 billion years old.

Cosmology Solved?
4.11.1998

At the Nature of the Universe Debate held last month at the Smithsonian, top cosmologists P. James E. Peebles (Princeton) and Michael S. Turner (Chicago) argued over whether new data is finally resolving the type of universe in which we live.

Unexpected Galaxy String in the Early Universe
20.01.2004

How could such a long string of galaxies form so early in the universe? Several new measurements of galaxies and clusters in the early universe are reporting structures involving galaxies and clusters that are larger than expected with the new standard "dark-energy" cosmology.

An X-ray Hot Supernova in M81
3.12.1995

In 1993, a star in the galaxy M81 exploded. Above is a picture of the hot material ejected by this supernova explosion. The picture was taken in X-rays with the Advanced Satellite for Cosmology and Astrophysics (ASCA).

The Year of Distant Supernovae
31.12.1998

Distant supernovae were among topics at the forefront of astronomy during 1998. Two independent groups raced to deploy large telescopes to scan the sky, discovering and analyzing far-off supernovae with the promise of calibrating the geometry of our universe.

The Galaxy and the Quasar
7.10.2002

Is the galaxy in the center connected to the quasar on the upper right? Disagreements about systems like this have raged for decades and have been used to challenge the foundations of modern cosmology.

David N. Schramm, 1945 - 1997
22.12.1997

David N. Schramm effectively combined the very big with the very small. Among his many scientific achievements, Schramm and collaborators successfully used Big Bang cosmology to predict that only three families of elementary particles exist in the universe, which was subsequently confirmed by high energy particle accelerators.

Simulating the Universe
8.11.1995

The above cube represents a chunk of our universe as simulated by the Grand Challenge Cosmology Consortium (GC3). The cube is huge - it would take light 500 million years to cross it. Low density gas is shown as blue, and high density gas as red.

A Universe in a Box
21.08.1997

Is this our universe? Possibly. It is one computerized guess of how gas in the universe was distributed billions of years ago, at redshift 3, when the universe was only a quarter of its present age.