Meteor shower over Toulouse and its region: “We are better protected than the dinosaurs”
It was not a flying saucer! The phenomenon observed last Monday by many witnesses in the Toulouse sky corresponded to a meteor shower, “the Gemenids”. Two CNES specialists, Vincent Costes from the Group for Studies and Information on Unidentified Responsible Aerospace Phenomena (Geipan) and Pierre Bousquet, expert in universe sciences, explain everything to us.
It was not a flying saucer! The phenomenon observed last Monday by many witnesses in the Toulouse sky corresponded to a meteor shower, “the Gemenids”. Two CNES specialists, Vincent Costes from the Group for Studies and Information on Unidentified Responsible Aerospace Phenomena (Geipan) and Pierre Bousquet, expert in universe sciences, explain everything to us.
What correspond to the fireballs observed all over the region last Monday?
The observations made in recent days and in particular this Monday, December 13 corresponding to shooting stars, the Geminids. It is a meteor shower every year in December with a peak of activity around December 13. The number of meteors entering the atmosphere can exceed 60 per hour. Regarding this Monday, December 13, GEIPAN in particular received the report of a singular event. It is a re-entry into the atmosphere of a rather large “racing car” of 2.5 kg and a diameter of around 10 cm. Falling stars are much smaller, grain-of-sand bodies. The phenomenon has been observed in France but also in Italy and Switzerland. It entered the atmosphere at a speed of about 50,000 km / h with a South-North trajectory. Such a racing car creates a very intense luminous disc as well as a large brilliant trail, capable of illuminating the landscape for several seconds. During the atmospheric reentry of a racing car, the very strong light can be perceived as very close, typically from 200 m to 2 km, while the phenomenon actually occurs at very high altitude starting at around 100 km and ending at 20 km from land.
Some witnesses reported green lights, is the phenomenon comparable to the Northern Lights?
The color associated with the re-entry into the atmosphere of a racing car may vary. It can be green, yellow or even white depending on the angle of incidence of the meteorite. It is associated with the emission of atmospheric gas and the ionization of the atmosphere violently heated by the extremely rapid movement of the solid body. You should know that the speed is greater than 40,000 km / h! In comparison, an aurora borealis is not created by a solid body. It is an interaction between charged particles, electrons, protons and ions, coming from the sun and the atoms and gases of the upper atmosphere. On the other hand, for both phenomena, the observed color is the spectral signature of the components of the atmosphere, namely the atoms of oxygen, hydrogen, nitrogen, etc. these components.
Are meteor showers of such magnitude frequent on our heads?
There are three shooting star observation sequences: the Quadrantids in January, the Perseids in August, and the Geminids in December. These are three very famous meteoric rains, regular and active each year.
Should we be worried about a more massive asteroid fall?
No, there is no need to worry: the catalog of near-Earth asteroids likely to encounter Earth is growing, and no asteroid impact is expected. The asteroid Apophis, for example, is closely followed as it regularly passes close to Earth. It will cross us at 35,000 km, anyway, on April 13, 2029, but any risk of collision is ruled out for at least a century. More broadly, the objective is to identify all objects exceeding 140 m in diameter, which are likely to cause a regional disaster. This should be accomplished by the NEO Surveyor mission which will be launched by NASA in 2026. CNES is participating in an international working group to define impact avoidance strategies.
Will the Dart mission, which must deviate the trajectory of an asteroid in space, make it possible to build an effective rampart to protect our planet?
DART will project on an asteroid a machine of half a ton at 24,000 km / h, and we will then measure the impulse transmitted to the target. This will calibrate this method to be ready should it ever be used on a truly threatening object. With enough anticipation, this technique is effective for bodies from 100 m to 1 km. For smaller objects, the deviation would not necessarily be justified, and evacuation measures might be sufficient. For objects, but we are talking about risks that have resulted in millions of years, it will be necessary to wait for a nuclear detonation which would deviate the trajectory by blast effect. We can afford to be better protected than the dinosaurs, which disappeared 66 million years ago because they had no space program!