Sighting in Saint-Paul, June 24, 2017

A witness was taking astrophotography images at the Maido peak on Réunion Island when an unusual luminous phenomenon appeared during the exposures. They described a track like a shooting star, which then turned into an intensely bright white cone of light and finally into a spherical, cloud-like glow whose trail took several minutes to fade. The witness sent their photographs to the GEIPAN. This was the only testimony collected.

The investigation established that the witness had seen the passage and then the passivation of the upper stage of a Falcon 9 launcher, launched on 23 June 2017 at 19:10 UT in Florida, which is 23:10 local time on Réunion. The rocket heads east along the equator; about an hour later it was already 8,000 to 10,000 km up, lit by the Sun and therefore visible over a wide area of the ground, in particular due east of Réunion. The witness's photo, reconstructed against the background stars, shows a straight trajectory pointing due east and sloping down toward the horizon, as the stage was about to pass behind the Earth as seen from the island. The cone corresponds to gas vented as the tanks were emptied during passivation, in a growing volume; the 40-second exposure turned it into a cone on the photo. The stage's reflection probably vanished because it was rotating, either naturally or at the time of passivation, which changed the mirror effect of the Sun.

The phenomenon is well known and has produced several reports, including one from Réunion with a similar geometry (an Ariane launch from Kourou, the ENTRE-DEUX case of 21.08.2015). These elements were enough for the GEIPAN to classify the case as A: rocket, without further work to reconstruct the stage's exact position in the sky.