A Distant Destiny
14.01.1998

Watching galaxies recede, observational astronomers of the 20th century discovered an astounding fact - the Universe is expanding. Will it continue to expand forever? The speed of light is finite so looking into the distant Universe is equivalent to looking at the distant past.

Weak Lensing Distorts the Universe
15.03.2000

Is the distant universe really what it appears to be? Astronomers hope not. Intervening dark matter, which is normally invisible, might show its presence by distorting images originating in the distant universe, much the way an old window distorts images originating on the other side.

WMAP Resolves the Universe
12.02.2003

Analyses of a new high-resolution map of microwave light emitted only 380,000 years after the Big Bang appear to define our universe more precisely than ever before. The eagerly awaited results from the orbiting Wilkinson Microwave Anisotropy Probe resolve several long-standing disagreements in cosmology rooted in less precise data.

The Hubble Deep Field
9.07.2000

Galaxies like colorful pieces of candy fill the Hubble Deep Field - one of humanity's most distant optical views of the Universe. The dimmest, some as faint as 30th magnitude (about four billion times...

The Hubble Deep Field
7.06.1998

Galaxies like colorful pieces of candy fill the Hubble Deep Field - humanity's most distant yet optical view of the Universe. The dimmest, some as faint as 30th magnitude (about four billion times fainter...

CMBR Dipole: Speeding Through the Universe
6.09.2009

Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group of Galaxies. The Local Group falls toward the Virgo Cluster of Galaxies.

Light from the First Stars
2.01.2007

What were the first stars like? No one is yet sure. Our Sun is not a first-generation star. It is not even second generation. The first stars to appear in the universe likely came and went about 13 billion years ago.

A Force from Empty Space: The Casimir Effect
17.12.2006

This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space.

Galaxies in the GOODS
25.06.2003

This tantalizing view of galaxies scattered near and far is part of the Hubble Space Telescope's contribution to the GOODS - the Great Observatories Origins Deep Survey project. The GOODS' goal is to study...

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.