Post by Andrei Tchentchik on Jul 8, 2019 17:28:20 GMT 2
(.#237).- Earth is preparing its defense against asteroids.
Earth is preparing its defense against asteroids.
By Tristan Vey - Updated on 14/04/2015 at 21:08
Artist's impression of an asteroid on a collision course with the Earth. MARK GARLICK / SPL / PHANIE / MARK GARLICK / SPL / PHANIE
INFOGRAPHY - Two American and European space missions will try to deviate the trajectory of a small rocky body.
Asteroids are a real threat to humanity. Experts estimate that a drop of one hundred meters every 1000 years. This type of pebble, which runs at tens of thousands of km / h, could wipe Paris off the map in the blink of an eye. If he fell into the ocean, he would raise a destructive wave several tens of meters high. A disaster for neighboring coastal cities.
Aware of this sword of astronomical Damocles, scientists meet every two years to take stock of knowledge accumulated on bodies that regularly cross the Earth's orbit (so-called NEOs) and potential solutions in case of danger. The 4th Global Defense Conference is being held this week in Frascati, Italy.
In addition to scientific conferences, this meeting is also an opportunity to carry out an impact simulation exercise. On Monday, participants learn about the discovery of a fictional asteroid posing a threat. Various working groups then study the trajectory, the possible consequences, the possible solutions, the communication to be adopted with the general public, etc.
Two years ago, during the first exercise of this type, the experts had failed to agree on the strategy to adopt, making the destruction of the city of Nice inevitable. "In the event of a real threat, we are clearly not ready," says Patrick Michel, CNRS research director at the Nice-Côte d'Azur Observatory, a world-renowned specialist in asteroids.
A long "asteroidal winter"
No space agency has yet completed a mission to divert or destroy asteroids. The European (ESA) and American (Nasa) agencies have joined forces to set up the Aida project, which plans to launch two probes in 2020 towards a double asteroid: Didymos, 800 meters in diameter around which a small moon turns, Didymoon, 170 meters.
"The European part, called AIM for Asteroid Impact Mission, is to send a probe to study and characterize this system, then put a small lander and deploy a micro-satellite in orbit," says its scientific leader, Patrick Michel. A few months later, in 2021, the Americans will send a 300 kg impactor, DART, to hit the smallest of the asteroids at a speed of 22,500 km / h.
"If the shock manages to eject material, it should significantly increase the deviation that will be studied by AIM," notes Patrick Michel. "Our goal is to predict through surface and internal structure studies how the impactor will influence the trajectory of asteroids."
The binary system will grow to about 1 million kilometers from the Earth in 2022. A distance close enough for scientists to validate the Didymoon trajectory change from the ground. "If the ESA gives up the AIM mission, NASA could continue the mission alone. If NASA gave up, the AIM mission could also work alone and bring back many scientific results. "
"We know only 20 to 30% of the tens of thousands of asteroids of a few hundred meters in diameter"
Patrick Michel, CNRS Research Director at the Nice Côte d'Azur Observatory.
The deviation of the asteroid should remain quite low. In case of real threat, it should be possible to launch a probe at least several years before the collision so that the disturbance is sufficient for the car to avoid the Earth. "Ideally, you should even send an exploratory probe before to study the structure of the asteroid to define the impactor needed to divert it from its path," said Patrick Michel. Not to mention that it would also be wiser to leave a little margin in case of failure for a second attempt.
Large asteroids can be detected well before their arrival. Astronomers, for example, closely follow all the kilometric bodies. Recall that a meteorite of about ten kilometers like the one that was fatal to the dinosaurs 65 million years ago would project into the atmosphere so much dust that it would cause a long "asteroidal winter", synonymous with extinction massive species.
In the case of smaller bodies, which still represent a very serious threat on a regional scale, there is no systematic research program. "We know only 20 to 30% of tens of thousands of asteroids of a few hundred meters in diameter," recalls Patrick Michel. The US nonprofit foundation B612, named after the Little Prince asteroid, hopes to launch its Sentinel infrared space telescope in 2018 to perform this crucial surveillance.
F I N .
Earth is preparing its defense against asteroids.
By Tristan Vey - Updated on 14/04/2015 at 21:08
Artist's impression of an asteroid on a collision course with the Earth. MARK GARLICK / SPL / PHANIE / MARK GARLICK / SPL / PHANIE
INFOGRAPHY - Two American and European space missions will try to deviate the trajectory of a small rocky body.
Asteroids are a real threat to humanity. Experts estimate that a drop of one hundred meters every 1000 years. This type of pebble, which runs at tens of thousands of km / h, could wipe Paris off the map in the blink of an eye. If he fell into the ocean, he would raise a destructive wave several tens of meters high. A disaster for neighboring coastal cities.
Aware of this sword of astronomical Damocles, scientists meet every two years to take stock of knowledge accumulated on bodies that regularly cross the Earth's orbit (so-called NEOs) and potential solutions in case of danger. The 4th Global Defense Conference is being held this week in Frascati, Italy.
In addition to scientific conferences, this meeting is also an opportunity to carry out an impact simulation exercise. On Monday, participants learn about the discovery of a fictional asteroid posing a threat. Various working groups then study the trajectory, the possible consequences, the possible solutions, the communication to be adopted with the general public, etc.
Two years ago, during the first exercise of this type, the experts had failed to agree on the strategy to adopt, making the destruction of the city of Nice inevitable. "In the event of a real threat, we are clearly not ready," says Patrick Michel, CNRS research director at the Nice-Côte d'Azur Observatory, a world-renowned specialist in asteroids.
A long "asteroidal winter"
No space agency has yet completed a mission to divert or destroy asteroids. The European (ESA) and American (Nasa) agencies have joined forces to set up the Aida project, which plans to launch two probes in 2020 towards a double asteroid: Didymos, 800 meters in diameter around which a small moon turns, Didymoon, 170 meters.
"The European part, called AIM for Asteroid Impact Mission, is to send a probe to study and characterize this system, then put a small lander and deploy a micro-satellite in orbit," says its scientific leader, Patrick Michel. A few months later, in 2021, the Americans will send a 300 kg impactor, DART, to hit the smallest of the asteroids at a speed of 22,500 km / h.
"If the shock manages to eject material, it should significantly increase the deviation that will be studied by AIM," notes Patrick Michel. "Our goal is to predict through surface and internal structure studies how the impactor will influence the trajectory of asteroids."
The binary system will grow to about 1 million kilometers from the Earth in 2022. A distance close enough for scientists to validate the Didymoon trajectory change from the ground. "If the ESA gives up the AIM mission, NASA could continue the mission alone. If NASA gave up, the AIM mission could also work alone and bring back many scientific results. "
"We know only 20 to 30% of the tens of thousands of asteroids of a few hundred meters in diameter"
Patrick Michel, CNRS Research Director at the Nice Côte d'Azur Observatory.
The deviation of the asteroid should remain quite low. In case of real threat, it should be possible to launch a probe at least several years before the collision so that the disturbance is sufficient for the car to avoid the Earth. "Ideally, you should even send an exploratory probe before to study the structure of the asteroid to define the impactor needed to divert it from its path," said Patrick Michel. Not to mention that it would also be wiser to leave a little margin in case of failure for a second attempt.
Large asteroids can be detected well before their arrival. Astronomers, for example, closely follow all the kilometric bodies. Recall that a meteorite of about ten kilometers like the one that was fatal to the dinosaurs 65 million years ago would project into the atmosphere so much dust that it would cause a long "asteroidal winter", synonymous with extinction massive species.
In the case of smaller bodies, which still represent a very serious threat on a regional scale, there is no systematic research program. "We know only 20 to 30% of tens of thousands of asteroids of a few hundred meters in diameter," recalls Patrick Michel. The US nonprofit foundation B612, named after the Little Prince asteroid, hopes to launch its Sentinel infrared space telescope in 2018 to perform this crucial surveillance.
F I N .
