Measure the distance between stars

For the first time, American astronomers estimated the average distance between stars in the universe.

Stars can burn out and die, but its light lasts forever. All the light that comes from stars still lurks somewhere in the universe, a phenomenon known as galactic background light (EBL).

Synthetic universe map from gamma radiation.Red light band represents the Milky Way

This is a kind of "mist" light, blurring the light from distant stars passing through it, like light from the lighthouse blurred in the fog.

Now, for the first time, astronomers can measure all EBL and calculate the distances of stars in the universe.

According to the Science report, the average density of stars in the universe is about 1.4 / 100 billion light-years. That means the average distance between stars is 4,150 light years.

To measure EBL, astronomers need a form of 'directions' to help them determine how much light has been lost. And according to Stanford University chief Marco Ajello, they chose blazar, galaxies emitting a large amount of gamma-ray radiation, capable of penetrating 'fog' effectively.

In the past four years, NASA's Gamma Fermi ray space telescope scanned the entire universe to find blazar, and identified more than 1,000 objects, from which to measure the combined mass of stars in the history of the universe.