Fig. 3: Plausible back-trajectories linking Falcon 9 to lithium observation.
From: Measurement of a lithium plume from the uncontrolled re-entry of a Falcon 9 rocket
A set of randomly perturbed back trajectories of the lithium plume from Kühlungsborn, calculated using winds from the UA-ICON model. The probability density heat map shows endpoints of many trajectories (blue) terminating in the region corresponding to the most likely origin of the lithium plume. One plausible back trajectory (coloured circles, colour indicates altitude) began at 00:21 UTC on 20 February over Kühlungsborn (54∘N, 12∘E) at an altitude of 97.1 km, and terminated at the Falcon 9 re-entry time, 03:42 UTC on 19 February, west of Ireland at (52.5∘N, 12.38∘W) and an altitude of 100.2 km. The best estimate for the Falcon 9 re-entry trajectory (courtesy of the European Space Agency) is plotted for comparison (black).
