The Milky Way is slowly “destroyed” by the gravity of a nearby galaxy

Astronomers say the Milky Way is gradually distorted and deformed by the gravitational force of the satellite galaxy, the Large Magellanic Cloud (LMC).

Researchers at the University of Edinburgh used a statistical model to calculate the velocity of the most distant stars in the Milky Way and our galactic neighbor.

The discovery overturns the belief that the Milky Way is relatively static, and therefore will require the production of new models to describe the evolution of the galaxy.

The Milky Way is attracted to the gravitational pull of the halo of dark matter surrounding the LMC at 71,600 miles per hour, causing it to deform.

This discovery will require researchers to re-evaluate how the Milky Way formed and what it could mean

Lead author Dr. Michael Petersen and colleagues showed that the LMC crossed the Milky Way boundary about 700 million years ago, recently by cosmological standards.

Due to its large dark matter content surrounding the satellite galaxy, it greatly disrupted the texture and motion of the Milky Way as it fell.

Dark matter is the mysterious “glue” that holds galaxies together: it has never been directly observed as it does not emit, reflect or absorb light.

The effects of this relatively recent collision are still visible today and should force a revision of the birth of the Milky Way, Petersen said.

LMC is now a satellite galaxy of the Milky Way – it is visible as a faint cloud in the southern hemisphere night skies.

The Large Magellanic Cloud is named after the 16th-century Portuguese explorer Ferdinand Magellan, who was the first to circumnavigate the Earth.

Previous research has revealed that the LMC – like the Milky Way and possibly all galaxies – is surrounded by a halo of dark matter beyond the galactic disk.

The researchers revealed that the enormous pull of the LMC’s dark matter halo is pushing the Milky Way’s disk to 71,600 miles per hour, or 20 miles per second.

To their surprise, the Milky Way was not moving in the direction of the LMC’s current position as previously thought, but at a point in its past trajectory.

It is twisted in the opposite direction – away from the CML itself – towards the constellation of Pegasus – in the northern sky.

This is because the LMC, powered by its enormous gravitational force, is floating at an even greater speed of 800,000 mph, or 230 miles per second.

The “chase” between the two galaxies has been likened to the Milky Way’s attempt to hit a fast-moving target, but it doesn’t aim very well.

The discovery will help scientists develop new modeling techniques that capture the strong dynamic interaction between the two galaxies.

Dr Petersen said: “ We have been able to show that stars at incredibly large distances – up to 300,000 light-years away – hold a memory of the Milky Way’s structure before the LMC fell and form a backdrop against which we measured the stellar disk flying through space, pulled by the gravitational force of the LMC. ‘

The astronomers now intend to find out the direction the LMC first fell from and the exact time it happened.

This will reveal the amount and distribution of dark matter in the Milky Way and LMC in unprecedented detail.

Co-author, Professor Jorge Penarrubia, also from Edinburgh, said: ‘This discovery definitely breaks the spell that our galaxy is in some sort of equilibrium state.

‘In fact, the recent fall of the LMC is causing violent disturbances on the Milky Way.

“Understanding them could give us unprecedented insight into the distribution of dark matter in both galaxies.”

Last year, a team from the University of Durham warned that the LMC will destroy Earth in about 2 billion years, awakening the Milky Way’s dormant black hole.

The results were published in the journal Nature Astronomy.