Planetary defense: James-Web detects 138 new asteroids large as a bus … or a stadium

Asteroids are a real threat to our blue planet. Non -avian dinosaurs know something about it, since they have all disappeared. The chixculub impactor, responsible for the latter large mass extinction, was between 10 and 15 km in diameter. With current technology and our Solar system monitoringit is not the biggest that constitute a real source of danger, because we know them well.

Those who can escape our vigilance are indeed the smallest, like 2024 YR4, now star of the spatial rocks of the moment. It was also discovered last December, when appeared the study which we echo.

If 2024 YR4 currently has approximately 2.3 % of terrestrial impact probability in 2032, with real chances that this percentage is revised down – what had happened with Apophis – On the other hand, we can be certain that one day, one of these unwavering modest size, more difficult to spot in time, will hit the ground after having partly burned in the atmosphere. Let us remember from Cheyliabinsk in February 2013, where the explosion of an asteroid of about 17 m had made a thousand injured, mainly by glass breakage due to the shock wave:

The “Vermine du Ciel” for professional astronomers

“For most astronomers, asteroids are considered to be the vermin of the sky, in the sense that they go through the field of vision and affect our data”explains Julien de Wit, one of the co-authors of the study. Here is the estimated impact frequency according to the sizes of the bodies concerned:

Famous discoverers of exoplanets find 138 new asteroids thanks to the JWST

The team that had discovered the Trappist-1 system and its seven exoplanets In 2015 had the idea of ​​looking in observation data of the NASA space telescope, the James-Webb (JWST) of unrivaled sensitivity in the infrared, if small asteroids could be uncovered . To do this, they used a subtle stacking method on more than 10,000 images taken during a JWST observation campaign. And these revealed much more than the astronomers had imagined: 138 new asteroids of a size ranging from the bus to that of a stadium!

“Previously, we could detect geocroisters up to 10 m in diameter when they were very close to the earthdeclares the main author of the study, Artem Burdanov, a MIT researcher. We now have a way to identify these small asteroids when they are much more distant, so that we can perform a more precise orbital prosecution, which is essential for planetary defense. ”

Between Mars and Jupiter

Of course – and fortunately -, these 138 asteroids discovered between the planets Mars and Jupiter are not all dangers. To become it, they will have to enter the category of geocroisors, that is to say that their trajectory leads them to cross the orbit of our land. Some will probably become it at some point in their journey and their interactions.

“It is a completely new and unexplored space in which we enter thanks to modern technologiesdeclares Mr. Burdanov. This is a good example of what we can do in our field when we look at the data differently. Sometimes there is a big profit, and it is one of them. ” We are luckier than dinosaurs …