Dead satellites falling to Earth could weaken its magnetic field

Satellites burning up as they fall to Earth could weaken its magnetic field, a new paper suggests. 

Under a worst-case scenario, they could even strip away part of our planet’s atmosphere.

Those are the findings of a new paper by physicist Sierra Solter-Hunt, who warns of the effects of dangers of growing satellite ‘megaconstellations’ such as those launched by Elon Musk’s SpaceX.

Ms Solter-Hunt suggests that ‘spacecraft dust’ from defunct satellites that burn up in the atmosphere may create enough magnetic dust to cut our planet’s protective shield in half. 

The paper, yet to be peer-reviewed, reveals the growing volume of magnetic particles left behind from dead satellites could create a band of plasma dust with a charge stronger than the rest of the magnetosphere – the part of Earth’s atmosphere that protects us from solar radiation. 

The net could create its own electrical charge and expose satellites to high levels of radiation and solar storms, as well as make it harder for rockets to launch new satellites and other spacecraft into space, as the magnetic particles could mess with the onboard electronics. 

‘I was shocked at everything that I found and that nobody has been studying this,’ said Ms Solter-Hunt, a doctoral candidate at the University of Iceland.

Speaking to Live Science, she added: ‘I think it’s really, really alarming.’

In the paper, she estimated that between 500,000 and 1 million private satellites could orbit our planet in the coming decades, with the primary aim of building megaconstellations to provide internet, such as SpaceX’s Starlink network that can be spotted orbiting the Earth. 

Private satellites have caused already begun to cause issues for astronomers, as they can interfere with radio telescopes and regularly ‘photobomb’ cosmic images – as well as posing a collision threat to other spacecraft. 

But the biggest issue comes when they die.

Most satellites burn up in the Earth’s atmosphere to reduce the amount of space junk floating about, but this leads to vapourised metal pollution. 

Currently, it is unknown where all the spacecraft dust will eventually end up, but Ms Solter-Hunt suggests it may end up in the upper part of the ionosphere – a region of the atmosphere between 50 and 400 miles above the surface.

It is here that Ms Solter-Hunt fears the magnetic dust will cause issues, although not all scientists agree.

But even if the increased levels of radiation could strip our atmosphere, Ms Solter-Hunt said this could take centuries, if not millennia, to occur.

The paper is uploaded to the pre-print database arXiv.