When part of aSpaceXrocket re-entered Earth’s atmosphere exactly a year ago, it created a spectacular fireball that streaked across Europe’s skies, delighting stargazers and sending a team of scientists rushing towards their instruments.
The German team managed to measure the pollution the rocket’s upper stage emitted in our planet’s difficult-to-study upper atmosphere — the first time this has been achieved, according to a study published on Thursday.
It is vital to learn more about this little-understood form of pollution because of the huge number of satellites that are planned to be launched in the coming years, the scientists emphasised.
In the early hours of February 19, 2025, the upper stage of a Falcon 9 rocket was tumbling back to Earth when it exploded into a fireball that made headlines from the UK to Poland.
“We were excited to try and test our equipment and hopefully measure the debris trail,” the team led by Robin Wing and Gerd Baumgarten of the Leibniz Institute of Atmospheric Physics in Germany told AFP via email.
In particular, the scientists wanted to measure how the rocket polluted what they call the “ignorosphere” — because it is so difficult to study.
This region between 50 to 100 kilometres (31 to 62 miles) above Earth includes the mesosphere and part of the lower thermosphere.
The team used technology called LIDAR, which measures pollution in the atmosphere by shooting out lots of laser pulses and seeing which bounce back off something.
They detected a sudden spike in the metal lithium in an area nearly 100 kilometres above Earth. This plume had 10 times more lithium than is normal in this part of the atmosphere.
The team then traced the plume back to where the rocket re-entered the atmosphere, west of Ireland.
Source: Insider Paper
