Rumors of a Strange Universe
27.02.2004

Only a few short years ago, when the APOD editors were in graduate school, the pervasive, cosmic Dark Energy was not even seriously discussed. Of course, it now appears that this strange energy dominates the cosmos (as well as lectures on cosmology) and provides a repulsive force accelerating the large scale expansion of the Universe.

The NTT SUSI Deep Field
15.09.1998

What happens if you point a large telescope at nothing? The above New Technology Telescope SUSI Deep Field photograph isolated a small patch of sky picked to contain no bright objects at all.

Supernova 1994D and the Unexpected Universe
30.12.1998

Far away, long ago, a star exploded. Supernova 1994D, visible as the bright spot on the lower left, occurred in the outskirts of disk galaxy NGC 4526. Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae.

NGC 1365: A Nearby Barred Spiral Galaxy
24.06.1999

Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a bar, but perhaps not so prominent as the one in NGC 1365, shown above. The persistence and motion of the bar imply relatively massive spiral arms.

The Sloan Digital Sky Survey Telescope
17.06.1998

The Sloan Digital Sky Survey (SDSS) will soon begin. Pictured above is the 2.5-meter telescope poised to create the most ambitious sky map in the history of astronomy. SDSS will catalog one quarter of the sky down past 23rd magnitude ( R), obtaining redshifts for galaxies and quasars brighter than magnitude 19.

Will the Universe End in a Big Rip
3.03.2003

How will our universe end? Recent speculation now includes a pervasive growing field of mysterious repulsive energy that rips virtually everything apart. Although the universe started with a Big Bang, analysis of recent cosmological measurements allows a possibility that it will end with a Big Rip.

Will the Universe End in a Big Rip
21.10.2007

How will our universe end? Recent speculation now includes a pervasive growing field of mysterious repulsive phantom energy that rips virtually everything apart. Although the universe started with a Big Bang, analysis of cosmological measurements allows a possibility that it will end with a Big Rip.

A Slice of the Universe with 2dF
14.06.2000

What can 100,000 galaxies tell you? Perhaps the structure and composition of the universe. Astronomers using the Two Degree Field (2dF) spectrograph on the Anglo-Australian Telescope (AAT) in Australia have now measured the redshifts of over 100,000 galaxies in a thin ribbon of the sky.

M100 and the Expanding Universe
9.01.1996

The distance to the swirling grand design spiral M100 is causing quite a stir among astronomers. Many believe that the Hubble Space Telescope's recent distance measurement to this galaxy accurately calibrates the expansion rate of the universe. Others believe this distance measurement is misleading.

The Universe Evolves
5.09.1999

Scroll right and watch the universe evolve. Above is a computer simulation depicting the evolution of our entire universe. On the far left is a slice of the universe soon after the Big Bang - over 10 billion years ago.