To foil the aluminium
Tare already several known threats posed by satellite constellations. I’m referring to those metallic bodies in low orbit that circle the earth in coordinated arrays, and which allegedly are to provide free internet to us, but which also form a major part of space military infrastructure. Now a terrifying new study by Canadian academics has highlighted yet another potentially deadly problem with them.
The question the researchers asked was, “What happens to the vapourised metals from these satellites when they reach the end of their lifespan and burn through the atmosphere?” The evidence led them to answers that are truly frightening. I’ ll give you a hint: the major composition of the satellites is aluminium.
Aaron Boley is an associate professor of astronomy and astrophysics at the University of British Columbia in Canada.
He is one of the authors of a paper published in May in the journal Scientific Reports. He and his co- authors conclude that the process of defunct satellites burning up and releasing their chemicals amounts to an uncontrolled geoengineering experiment with unknown consequences. Boley told that “with the first generation of Starlink, we can expect about 2 tonnes of dead satellites reentering Earth’s
HERE Space. com
atmosphere daily. These satellites are mostly aluminum, [ unlike natural rock meteroids] which the meteoroids contain only in a very small amount, about 1%.” To be clear, when we talk about these satellite constellations, we are not just talking about a handful of odd satellites that may stop working here and there, we are talking about hundreds of thousands of them that will definitely stop working at some point.
Each Starlink satellite weighs 227 kilogrammes. There are already 1700 of them in orbit. The first phase plans to have 12 000 of them, and the full complement plans over 100 000 of them. Starlink is not the only company launching such satellite constellations.
When these satellites cease working and their orbits decay, they fall back into the planet’s atmosphere, burning up upon reentry. When aluminum is burned, it produces aluminum oxide, a chemical which is also known as alumina, and which is known to have effects on the atmosphere.
“Alumina reflects light at certain wavelengths and if you dump enough alumina into the atmosphere, you are going to create scattering and eventually change the albedo of the planet,” Boley said. Changing the reflectivity of the planet in this manner has already been proposed – and rejected for being too uncontrolled and potentially too dangerous – as a method for slowing global warming processes.
“Now it looks like we are going to run this experiment without any oversight or regulation,” Boley told Space. com. “We don’t know what the thresholds are, and how that will change the upper atmosphere.”
Boley went on to caution that it’s not just a change in albedo, but the effects that alumina will have on the ozone layer. “We know that alumina does deplete ozone just from rocket launches ( which) have alumina as a byproduct.
That creates these little temporary holes in the stratospheric ozone layer.”
The satellites are expected to burn up in a region of the atmosphere just above the ozone layer, but with the contents eventually settling into the ozone- rich stratosphere. It’s literally chilling.