Les Astronomes Ont Découvert 100 Nouveaux Astéroïdes - Et La Terre Est Sur Leur Trajectoire - video Dailymotion

Sympa

Les astronomes viennent de découvrir 100 nouveaux astéroïdes, et devinez quoi ? Certains d'entre eux volent un peu trop près pour être rassurants ! 🌍💥 Ces roches spatiales étaient cachées dans une zone difficile à repérer entre la Terre et le Soleil, ce qui les rendait difficiles à détecter jusqu'à présent. Les scientifiques surveillent maintenant de près leurs trajectoires pour voir si l'un d'entre eux pourrait représenter un danger réel à l'avenir. La bonne nouvelle ? Nous disposons de plus d'outils que jamais pour les suivre et éventuellement les dévier si nécessaire. Mais tout de même, c'est un rappel saisissant que l'espace est plein de surprises—et que la Terre est en plein milieu de tout cela ! 🚀🔭  Animation créée par Sympa. ---------------------------------------------------------------------------------------- Musique par Epidemic Sound https://www.epidemicsound.com   Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna​ ---------------------------------------------------------------------------------------- Nos réseaux sociaux : Facebook: https://www.facebook.com/sympasympacom/ Instagram: https://www.instagram.com/sympa.officiel/  Stock de fichiers (photos, vidéos et autres): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ----------------------------------------------------------------------------------------  Si tu en veux encore plus, fais un tour ici:  http://sympa-sympa.com

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00:00And if we cooked a little? No, no pasta and no hamburgers for today.

00:05What would you say of something more exotic? Or rather, more cosmic?

00:09So here it is, the recipe is simple. You take a team of enthusiastic astronomers

00:14and you add some old images from the James Webb Space Telescope.

00:19You mix well and you get an impressive number of small asteroids,

00:23all located in the big belt between Mars and Jupiter, Miam.

00:28The highlight of the show is the direction in which some of these asteroids are moving.

00:33Because on their way there is our poor planet.

00:36Are we simply condemned because you decided to cook?

00:39The asteroids I'm talking about are much smaller than the huge space rock that destroyed the dinosaurs.

00:45But they can still cause considerable damage. Their size varies.

00:50They can be as small as a bus or as big as a stadium.

00:54But even the smallest are very dangerous.

00:57Let's take a recent and quite spectacular example.

01:00It happened on February 15, 2013.

01:02A small asteroid, just a few dozen meters wide, exploded in the atmosphere above Chelyabinsk,

01:09in Siberia, releasing an incredible amount of energy.

01:13Many people witnessed the event and filmed it,

01:17which allowed scientists to obtain essential clues.

01:20New computer models helped scientists reconstruct the size, speed and impact of the Chelyabinsk meteor.

01:28It was probably a big asteroid like a five-story building,

01:32and it would have exploded at an altitude between 24 and 29 km above the Earth's surface.

01:39And with incredible force.

01:41The explosion broke a million windows and injured more than a thousand people.

01:46Fortunately, it was not powerful enough to cause real damage.

01:49But it gave us an idea of the danger that an air explosion can represent.

01:54An air explosion occurs when an object explodes high in the atmosphere,

01:58never touching the ground, but releasing enough energy to devastate the area below.

02:04But let's go back to our little asteroids.

02:06The most dangerous thing with them is that they hit the Earth much more often than the bigger ones,

02:11about 10,000 times more often.

02:13To make matters worse, their small size makes them more difficult to detect in advance,

02:17which leaves us little time to prepare if one of them is heading for the Earth.

02:22Now let's go back to the time of the dinosaurs.

02:24Oh no, that's too far.

02:26Ah here it is.

02:27A team of astronomers worked on a method consisting of finding small asteroids in telescope images

02:32which were originally taken to study distant stars.

02:36Thanks to this method, they were able to examine with precision a stellar system known as TRAPPIST-1,

02:42located 40 light-years from the Earth.

02:45This is one of the most studied systems outside our solar system.

02:49By analyzing these images, they discovered 138 new asteroids in the main asteroid belt,

02:55in addition to the 8 that they already knew.

02:58And guess what?

02:59Among the newly discovered asteroids,

03:016 seem to have been pushed along trajectories that could bring them closer to the Earth.

03:06Who did that?

03:07Probably close planets.

03:09Do they have a tooth against us?

03:11Interesting fact.

03:12Scientists thought they were only finding a few new asteroids,

03:15but their number turned out to be much higher than expected.

03:18But this is not surprising.

03:20They are currently exploring part of the space they knew little before.

03:24Let's now talk about the hero of the day, the James Webb Space Telescope.

03:28If it is so effective in finding small asteroids, it is because it can detect their heat.

03:33These asteroids emit an infrared radiation,

03:36much more visible than the weak sunlight reflecting on their surface.

03:40This technology has allowed scientists to detect the smallest asteroids ever observed in the main asteroid belt.

03:47The asteroids they found are fragments from collisions between larger space rocks.

03:53Discoveries allow astronomers to understand the history of this belt

03:57and to improve the tracking methods of the small asteroids likely to threaten the Earth.

04:02Researchers plan to use the James Webb to observe other stellar systems for at least 500 hours.

04:09They hope this work will allow them to discover thousands of other small objects in the solar system.

04:15Other high-end telescopes, such as the Verace Rubin Observatory in Chile, will also be useful.

04:20As of 2025, this observatory will use the largest digital camera in the world

04:26to photograph the starry sky every night for at least 10 years.

04:30Each image will cover a vast area of the sky, about 40 times the size of the full moon.

04:36The observatory could find up to 2.4 million asteroids in just 6 months,

04:41almost double the number we know.

04:43Recently, NASA identified two small asteroids.

04:47They were to pass near Earth on December 16, 2024.

04:51Fortunately, neither one nor the other posed any danger to the planet.

04:55The first asteroid was 21 meters wide,

04:58about the size of a large plane, and moved at 17,400 km per hour.

05:03The second asteroid was slightly smaller, with a width of 17 meters,

05:08but it moved faster, at 23,800 km per hour.

05:12But hey, even if this time we avoided disaster, who knows what the future holds for us.

05:17Ouch, ouch, ouch.

05:19It may seem strange nowadays,

05:21but astronomers have not really been interested in small asteroids for quite a long time.

05:26They considered them as simple spatial debris that hindered the observation of the stars.

05:32Some even called them the parasites of the sky.

05:36But today, the way we see these small space rocks has completely changed.

05:41In fact, until recently, we could only spot the very large asteroids,

05:45those over 1.6 km wide.

05:48The smaller ones were found in the background noise, images taken by telescopes.

05:53But then, an ingenious trick allowed to combine several images of the same part of the sky,

05:58and to finally make visible these small objects that are not very bright.

06:01The data from some telescopes, such as TRAPPIST and SPECULOOS,

06:05as well as from the James Webb Space Telescope,

06:08help us to improve planetary defense.

06:11But it is not only about protecting our planet.

06:14The study of these small asteroids also teaches us how the solar system has evolved.

06:19If they are so numerous, it is because they are fragments

06:22from collisions between larger space rocks.

06:25A researcher said that it was as if we were looking at old data in a new way.

06:30These small asteroids, which were previously considered as simple debris,

06:34are essential to understand our solar system,

06:37and even to prepare for what the future holds for us.

06:40Among these hundreds of millions of rocks orbiting around the Sun,

06:44in the asteroid belt, located between Mars and Jupiter,

06:47some are particularly worrying.

06:49They are close enough to Earth to be worrying.

06:53NASA classifies asteroids orbiting less than 48.28 million km from our planet

06:59as geocrossing objects.

07:01And this could be a serious threat if they were to collide with our planet.

07:06Currently, NASA is closely monitoring an asteroid named Bennu.

07:10It is a fairly large space rock measuring about 490 meters in diameter.

07:15It could potentially crash on Earth in 159 years.

07:19Astronomers spotted it for the first time in 1999.

07:23Currently, experts estimate that there is a low probability that Bennu will drift into Earth's orbit

07:29and collide with our planet by September 24, 2182.

07:34Would that be serious?

07:36Well, to put things in perspective, Bennu is larger than the Empire State Building.

07:41If it hit Earth, it would release 1,200 megatons of energy,

07:45a quantity so huge that nothing on Earth could generate it.

07:49NASA scientists are particularly concerned about the probability

07:53that this asteroid will pass through a gravitational lockhole

07:57during its passage to the 22nd century.

08:00This lockhole is a region of space that could place the asteroid

08:04on a direct collision path with Earth.

08:07Bennu passes near Earth every six years and has already approached it three times,

08:11in 1999, 2005 and 2011.

08:14At present, scientists estimate that the probability that the asteroid will hit Earth by 2182

08:20is about 1 in 2700,

08:23a risk more than five times higher than that of a person being hit by lightning.

08:28Although the chances that the asteroid Bennu will collide with Earth are very low at the moment,

08:33this space rock is still classified as potentially dangerous,

08:38because it could approach up to 7.48 million kilometers from Earth.

08:43The asteroid Apophis is another space rock that we must monitor.

08:47It is a geocruiser object of about 335 meters in diameter, discovered in 2004.

08:52At first, it was considered one of the most dangerous asteroids ever detected.

08:57Apophis quickly attracted the attention of experts,

09:00because they thought it could represent a serious threat to Earth

09:04due to its proximity to our planet in 2029.

09:07However, after a more in-depth study of its orbit,

09:11astronomers have determined that there was no risk of collision before at least a century.

09:16Phew, we can be calm for a little while longer.

Les Astronomes Ont Découvert 100 Nouveaux Astéroïdes - Et La Terre Est Sur Leur Trajectoire

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