By- Srishti Verma
Concerns regarding possible effects on the planet's climate have been raised by the discovery of contaminants from the burning of space debris in the atmosphere
Researchers flew over Alaska and the continental United States in high-altitude missions on NASA's WB-57 and ER-2 aircraft
Their goal was to gather chemical samples from the stratosphere, the second-lowest atmospheric layer on Earth
The study team was able to travel at altitudes up to 11.8 miles (19 km) above the cruise altitude of commercial airplanes
Sensitive sensors in the aircraft's nosecones detected chemical substances in the pristine stratospheric air that was free of pollution from the ground
Notably, the researchers discovered levels of lead, copper, aluminum, lithium, and lithium in the samples that were gathered.
These substances were present in concentrations that were higher than those that might be attributed to natural sources, such as meteorite evaporation and cosmic dust.
Dan Cziczo, a professor at Purdue University saying, "We are finding this human-made material in what we consider a pristine area of the atmosphere, and if something is changing in the stratosphere — this stable region of the atmosphere — that deserves a closer look."
Scientists have recently grown more concerned about the possible effects on Earth's upper atmospheric layers of the rising frequency of rocket launches and satellite re-entries.