Even Albert Einstein didn't realize the universe could expand this fast. After using the Hubble Space Telescope to measure how far away stars in 19 other galaxies were, NASA and the European Space Agency have concluded that the universe is actually expanding at a rate 5 percent to 9 percent faster than all previous calculations — including Einstein's theory of relativity — had estimated. Astronomers now say that the rate of expansion is "45.5 miles per second per megaparsec (3.26 million light-years)," which means that in 9.8 billion years the Milky Way will be twice as far away from other galaxies than it is now, The Washington Post reports.
Aside from posing a potential challenge to Einstein's theory — which has largely withstood questioning for the past century — the new discovery also raises problems with scientists' notion that leftover energy from the Big Bang is the sole cause of the universe's steady outward growth. "If you really believe our number — and we have shed blood, sweat, and tears to get our measurement right and to accurately understand the uncertainties — then it leads to the conclusion that there is a problem with predictions based on measurements of the cosmic microwave background radiation, the leftover glow from the Big Bang,” study co-author Alex Filippenko of UC Berkeley said.
Though the newly discovered discrepancy still needs to be verified, it could mean there's something out there in space pushing the universe apart that we don't yet know about.