Astronomers who are using NASA's Hubble Space Telescope have discovered that the universe is expanding 5 percent to 9 percent faster than what was expected.

Adam Riess, a study leader from The Johns Hopkins University and his team made the discovery by refining the universe's current expansion rate by developing new techniques that improved the precision of distance measurements to galaxies which are located faraway.  By using these techniques, it reduced the uncertainty to only 2.4 percent.

One theory is that a new type of subatomic particle may have changed the balance of energy in the early universe. Astronomers used Hubble to measure the distances to stars in 19 galaxies with more precision as compared to earlier research.

In 1998, Hubble observations made the ground-breaking discovery of the universe expanding and that to at a faster rate. It is believed that an invisible force called dark energy is repelling galaxies, but the secrets about this energy are still shrouded in mystery.

The results of the discovery will appear in The Astrophysical Journal.