dark energy

Ten times more galaxies

A new “super survey” is producing the largest database of galaxy measurements, spanning the last five billion years of cosmic history.

The international GAMA (Galaxy and Mass Assembly) project is combining data from ground- and space-based observatories to measure the dark matter “haloes” that surround galaxies. Dark matter, its nature still unknown, makes up 24% per cent of the universe.

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Spinning galaxies reveal missing matter

Australian astronomers have long been contributing to our understanding of a strange cosmological phenomenon—the Universe’s missing matter. In the early 1970s, Ken Freeman of the Australian National University (ANU) determined that spiral galaxies must contain more matter than we can see. He postulated that dark matter—an invisible material first proposed 40 years earlier—must make up [...]

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Galaxies point the way to dark energy

A project to produce more than double the number of galaxy distance measurements than all other previous surveys combined, could lead to an explanation of one of nature’s biggest mysteries.

In 1998, astronomers announced that the expansion of the universe is not slowing down as many people had thought, but rather is speeding up. To account for this, scientists have invoked an invisible force called “dark energy”, which makes up 75% of the cosmos’ total of energy and matter in the cosmos. Dark energy opposes gravity, and makes the universe want to spread out.

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L’Oréal Fellow looking for dark energy

In 1998 astronomers made an astonishing discovery—the expansion of the Universe is accelerating. The discovery required a complete rethink of the standard model used to explain how the Universe works.

“Now we know that stars, planets, galaxies and all that we can see make up just four per cent of the Universe,” says Dr Tamara Davis, a University of Queensland astrophysicist.

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