LONDON, May 20 (UPI) -- U.S and Australian scientists say a major astronomical survey using cutting-edge techniques appears to have confirmed the existence of mysterious dark energy.

Dark energy is thought to comprise about 74 percent of the universe and its existence has been theorized to explain why the universe appears to be expanding at an accelerating rate, the BBC reported Thursday.


The finding was based on studies of more than 200,000 galaxies and involved two techniques -- measuring a pattern in how galaxies are distributed in space and determining how quickly clusters of galaxies have formed.

Both have apparently confirmed the existence of dark energy and the acceleration of the speed of expansion in the universe, papers accepted for publication in the Monthly Notices of the Royal Astronomical Society journal said.

The theory of dark energy was first put forward in the 1990s.

To account for the accelerating expansion of the, astronomers had either to rewrite Albert Einstein's theory of gravity or accept that the cosmos was filled with a type of energy not yet observed.

"The action of dark energy is as if you threw a ball up in the air, and it kept speeding upward into the sky faster and faster," said co-author Chris Blake of the Swinburne University of Technology in Melbourne, Australia. "The results tell us that dark energy is a cosmological constant, as Einstein proposed. If gravity were the culprit, then we wouldn't be seeing these constant effects of dark energy throughout time."

However, despite being able to infer the existence of dark energy, the phenomenon still eludes a full explanation, scientists say.