SPECTRAL SIGNATURE OF SATELLITE FRAGMENTS REENTERING THE EARTHS ATMOSPHERE - A LABORATORY SIMULATION

In order to distinguish between the re-entry into the Earth's atmosphere of a man-made object, such as a fragment of a satellite, and a natural meteorite, we have performed a series of tests in which high time resolution spectroscopy has been used to record the spectrum of aluminium alloy projectiles travelling at 9.7 +/- 0.05 km s-1 in a rarefied atmosphere, at the pressure existing on Earth at 65 km altitude. A strong emission was found in the coma, corresponding to the five emission bands of the excited metastable aluminium monoxide molecule, AlO. Emissions from atmospheric gaseous components appeared superimposed on the emission bands of the AlO, which grow weaker with the time evolution of the trail.