in

Our solar system could eventually die by being ground into dust as it is pulled into the sun

Our solar system could eventually die by being ground into dust as it is pulled into the Sun when it becomes a white dwarf, scientists believe.

That is if it hasn’t already been ‘eaten up’ by our expanding Sun.

When our host star, the Sun, runs out of fuel, it will become a white dwarf, exerting a huge gravitational pull that could suck our system into it where it will be crushed, say astrophysicists.

Professor Boris Gaensicke of the Department of Physics, University of Warwick, said: “The sad news is that the Earth will probably just be swallowed up by an expanding Sun, before it becomes a white dwarf.

“For the rest of the solar system, some of the asteroids located between Mars and Jupiter, and maybe some of the moons of Jupiter may get dislodged and travel close enough to the eventual white dwarf to undergo the shredding process we have investigated.”


Debris from a disrupted planetesimal on an eccentric orbit around a white dwarf, with a moon and falling meteorite in space
Clumps of debris from a disrupted planetesimal are irregularly spaced on an long and eccentric orbit around the white dwarf.

Researchers investigated the fate of asteroids, moons and planets which pass close to the white dwarfs, by analysing transits, which are dips in the brightness of stars caused by objects passing in front of them.

Unlike the predictable transits caused by orbiting planets around stars are predictable whereas those caused by debris are oddly shaped, chaotic and disorderly.

Dr Amornrat Aungwerojwit of Naresuan University, Thailand, who led the study, said: “Previous research had shown that when asteroids, moons and planets get close to white dwarfs, the huge gravity of these stars rips these small planetary bodies into smaller and smaller pieces.”

“Collisions between these pieces eventually grind them into dust, which finally falls into the white dwarf, enabling us to determine what type of material the original planetary bodies were made from.”

In this new research, scientists investigated changes in brightness of stars for 17 years, shedding insight into how these bodies are disrupted.

The study, published in the journal Monthly Notices of the Royal Astronomical Society (MNRAS) focused on three different white dwarfs which all behaved very differently.

Professor Gaensicke commented: “The simple fact that we can detect the debris of asteroids, maybe moons or even planets whizzing around a white dwarf every couple of hours is quite mind-blowing, but our study shows that the behaviour of these systems can evolve rapidly, in a matter of a few years.

“While we think we are on the right path in our studies, the fate of these systems is far more complex than we could have ever imagined.”

One of the white dwarves studied, WD 1145+017, had been shown by Massachusetts Institute of Technology in 2015 to behave close to theoretical predictions.

 Surprisingly in this latest study, the transits are now totally gone.

Professor Gaensicke said: “The system is, overall, very gently getting brighter, as the dust produced by catastrophic collisions around 2015 disperses.

“The unpredictable nature of these transits can drive astronomers crazy – one minute they are there, the next they are gone. And this points to the chaotic environment they are in.”

This study is published today in the journal.

Written by New York Post