For neutrinos created recently, the ranges they can exist in are very, very small. But over the roughly 13.7-billion-year lifetime of the cosmos, "relic" neutrinos have been stretched out by the expansion of the universe, enlarging the range in which each neutrino can exist.

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Cosmologists don't usually take their lead from the animal kingdom. But a model that postulates the existence of a 'chameleon' particle — which would change its mass depending on its surroundings — is gaining attention. More Articles

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Whatever dark energy is, explanations for it have less wiggle room following a Hubble Space Telescope observation that has refined the measurement of the universe's present expansion rate to a precision where the error is smaller than five percent. More Articles

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NASA released this week five years of data collected by the Wilkinson Microwave Anisotropy Probe (WMAP) that refines our understanding of the universe and its development. It is a treasure trove of information, including at least three major findings:

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"Most astronomers say that world-famous images from the Cosmic Background Explorer satellite show structures of the early universe. But a lone radio astronomer is claiming that the pictures depict nearby hydrogen gas clouds in our own galaxy, calling a key theory into question."

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by Zeeya Merali Some believe it is just a figment of overactive imaginations. But evidence is growing that the so-called "axis of evil" - a pattern apparently imprinted on the radiation left behind by the big bang - may be real, posing a threat to standard cosmology.

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We're talking about when the universe was less than a trillionth of a trillionth of a second old. In that crucial split second, changes occurred that allowed for the creation of stars and galaxies hundreds of millions of years later.

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NASA press conference announces observations revealing what the universe was like in the first trillionth of a second after the Big Bang.

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