An account in Yvelines, France

On April 14, 2013 at around 8 p.m., a witness observed the movement of about fifteen very bright points in the sky. They were moving in the same direction. No particular noise was heard during the observation, which lasted about twenty seconds. Four minutes before sunset, the witness observed toward the East about fifteen disordered bright points, moving toward the Southeast, and seeming to "flash." This observation may correspond to metallic balloons (Mylar) moving in the wind: the wind at ground level is from the South, but soundings taken at Trappes indicate that the wind blows from the Northwest at altitude, which is consistent with the observation. This type of balloon, filled with helium, can rise very high and last several hours. Their origin is very difficult to find. GEIPAN classifies this case "B": probable observation of festive helium-filled balloons.