Hubble helps in precise measurement of universe's expansion

Astronomers, using the Hubble Space Telescope, have measured the precise rate at which the universe is expanding, by employing a technique completely independent of any previous method.

The researchers noted that knowing the precise value for how fast the universe expands is important for determining the age, size, and fate of the cosmos.

Unravelling this mystery has been one of the greatest challenges in astrophysics in recent years, thy said.

The study adds evidence to the idea that new theories may be needed to explain what scientists are finding, NASA said in a statement.

The finding strengthens a troubling discrepancy between the expansion rate, called the Hubble constant, calculated from measurements of the local universe, and the rate as predicted from background radiation in the early universe, a time before galaxies and stars even existed, it said.

This latest value represents the most precise measurement yet using the gravitational lensing method, where the gravity of a foreground galaxy acts like a giant magnifying lens, amplifying and distorting light from background objects.

The study did not rely on the traditional "cosmic distance ladder" technique to measure accurate distances to galaxies by using various types of stars as "milepost markers."