update: CNN's November 7, 2023 Japanese scientists want to send a wooden satellite into space links to October 16, 2023 NOAA scientists link exotic metal particles in the upper atmosphere to rockets, satellites
“Two of the most surprising elements we saw in these particles were niobium and hafnium,” said Chemical Sciences Laboratory research chemist Daniel Murphy, who led a team including scientists from CIRES, Purdue and the University of Leeds. “These are both rare elements that are not expected in the stratosphere. It was a mystery as to where these metals are coming from and how they’re ending up there.”
[...]
While Murphy and his coauthors estimate that 10% of stratospheric sulfuric acid particles currently contain traces of metals from rockets and satellites, they say that could grow to 50% or more based on the number of satellites being launched into low-earth orbit, and efforts to eliminate space debris at end-of-life by directing it into the atmosphere to burn up.
“There will be a lot of work to understand the implications of these novel metals in the stratosphere,” Murphy said.
As of October 4, the tracking website Orbiting Now lists 8,697 satellites currently in orbit, 7,892 of which are in low Earth orbit and are destined to burn up on reentry.
“At 10%, the current fraction of stratospheric aerosol with metal cores is not large.” said co-author Martin Ross of The Aerospace Corporation. “But over 5,000 satellites have been launched in the past five years. Most of them will come back in the next five, and we need to know how that might further affect stratospheric aerosols.”
Credit: Chelsea Thompson/NOAA
This in turn links to the published results in October 16, 2023 PNAS: Metals from spacecraft reentry in stratospheric aerosol particles
