Why is space black?

Imagine you're in space. Just the floating part, not the peeing into a vacuum hose or eating that funky "ice cream" from foil bags part. If you looked at the Sun, it would be bright and your retinas would crisp up. The rest ...

Is dark matter made of primordial black holes?

Astronomers studying the motions of galaxies and the character of the cosmic microwave background radiation came to realize in the last century that most of the matter in the universe was not visible. About 84 percent of ...

Universe older than it looks

When astronomers (Bond 2013) first dated the star HD 140283, which lies a mere 190 lightyears from Earth in the constellation of Libra, they were puzzled. This rare, star appeared to be rather ancient and was quickly nicknamed ...

A massive galaxy supercluster in the early universe

The structure of the universe is often described as being a cosmic web of filaments, nodes, and voids, with the nodes being clusters of galaxies, the largest gravitationally bound objects known. These nodes are thought to ...

First stars formed even later than previously thought

ESA's Planck satellite has revealed that the first stars in the Universe started forming later than previous observations of the Cosmic Microwave Background indicated. This new analysis also shows that these stars were the ...

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