Even the space junk designed with disposal in mind is a polluting presence around Earth, a new study has found. Those chunks of rocket and space station and dead satellites that burn up on atmospheric reentry leave miniscule traces of metal lingering...
I've been thinking about this for a while. All these starlink satellites are ^just going to burn up on reentry. That's like throwing tv's into the bonfire and saying "don't worry, they burn"
Every day multiple tons of micrometeoroids burn up on entry. So yeah there is a reason why no one really gave a shit when the occasional satellite burns up.
i think there are about 8.000t of man made orbital objects up there right now.
The earth has 510.100.000 square km of surface.
That boils down to 15g of material per square km.
Now be assured...if u life in a city, or even near a street with car traffic you are allready living with way way higher levels of polution than orbital objects could cause....unless a Rorsat with a nuklear reactor decides to crash in your backyard.
Orbital littering is a real problem, but its dwarfed by the gigantic amount of trash and polution we allready have on earth...even if all the orbital objects would come down tomorrow...u would not notice the increase of polution.
15,000 Tons of material rains down on Earth from space each year. Only 5,200 Tons of it makes it down to the ground. The rest burns up.
So, 9,800 of stuff already burning up each year. Now, most of that is silica or carbon, but there are certainly also metals. Now, more metals from man made shit is a concern, but not maybe the most pressing things...
Then again, metal particles in the air are never good. And not something that you see in the atmosphere anywhere but metal foundries. It's actually quite the issue.
Overall, I'd say increasing the atmospheric metal content is a bad thing, but still less of an issue than some of the other things
Avgas is a specialized fuel used to power piston engine aircraft.
Jet aircraft and turbine-powered, propeller aircraft do not use avgas, but instead use fuels very similar to kerosene, which does not contain a lead additive.