Nasa’s Hubble Telescope spots ‘protective shield’ around distant galaxies

‘A lot of people were struggling to explain how these streams of material could be there’

Nasa’s Hubble telescope has spotted “protective shields” around distant galaxies.

The phenomenon has long been theorised by scientists, but has been confirmed to exist for the first time.

Our Milky Way’s biggest neighbours are known as the Large and Small Magellanic Clouds, and have a difficult time as they tumble through space. They are pulled apart not only by each other’s orbits, but also the Milky Way itself.

But still the galaxies have remained together, intact, and are even making new stars.

“A lot of people were struggling to explain how these streams of material could be there,” said Dhanesh Krishnarao, assistant professor at Colorado College. “If this gas was removed from these galaxies, how are they still forming stars?”

Scientists have thought that those galaxies must be protected somehow, so that the contents can be kept safe during collisions. Now researchers have finally seen that protection: a vast, cosmic bumper.

It works like a cosmic cocoon, made of gas, which can absorb some of the impacts.

“Anything that tries to pass into the galaxy has to pass through this material first, so it can absorb some of that impact,” said Krishnarao in a statement. “In addition, the corona is the first material that can be extracted. While giving up a little bit of the corona, you’re protecting the gas that’s inside the galaxy itself and able to form new stars.”

The corona is probably the leftovers of a cloud of gas that collapsed and formed the galaxy in the first place, billions of years ago, scientists said.

Scientists had been predicting the existence of such a protection for years. But the new research is the first time that it has been seen directly.

The discovery is reported in a new paper, ‘Observations of a Magellanic Corona’, published in the journal Nature.