Why Is There More Light Than There Should Be in the Universe?

And it might have to do with dark matter.

Transcript

00:00NASA's New Horizons probe is now way out past Pluto, in the darkest reaches of our

00:09solar system.

00:10But there's just one thing.

00:11It isn't as dark as expected.

00:12The spacecraft has been picking up twice the amount of light on the optical spectrum as

00:16expected.

00:17But it's not coming from stars, but rather from between them, and it might actually have

00:21to do with one of the universe's greatest mysteries.

00:24Dark matter.

00:25Dark matter remains elusive because it cannot be detected directly.

00:28Rather it's the name we've given to the cause of excess gravity when calculating cosmic

00:31masses.

00:32But if dark matter is real, scientists say it accounts for 80% of all matter in the universe.

00:37So how are we seeing light out in space produced by dark matter if we can't detect dark matter?

00:42Well experts say it might have to do with hypothetical particles called axions.

00:46Axions might be the solution to why there's so much gravity in the universe.

00:49Or it could actually be the dark matter scientists are looking for.

00:52Which is why this discovery is so important, as scientists have now been able to put together

00:56a mathematical model that reveals that axions with a mass between 8 and 20 electron volts

01:01could create all this extra light New Horizons detected, meaning we may be one step closer

01:05to understanding axions, and by default, maybe even dark matter.