In Mexico, there is a crater with a diameter of up to 180 kilometers and a depth of up to 900 meters. It is said that this is the trace left by a meteorite with a diameter of about 10 kilometers 65 million years ago, and what followed was the destruction of the dinosaur, a generation of overlords on Earth.
Human beings have always had a concern that we are not absolutely safe in the universe. More than 28,000 asteroids around the earth are flying around it. Will one day the disaster come from flying?
One day, if an asteroid really hits the earth, what should we do? Therefore, many countries have joined the asteroid defense system, improve their monitoring capabilities for asteroids, and form near-Earth defense systems.
Unprecedented
For the first time, NASA crashed the spacecraft into an asteroid. This mission is to use the "Dual Asteroid Redirection Test" (DART) spacecraft to hit the asteroid "Dimorphos" to deviate from its original orbit. This is also the first time in human history that attempts to deviate from the orbit of an asteroid.
Objects in the universe will be attracted by gravity, and celestial bodies will run in space according to this established orbit. Once there is a strong external force, its original track may change. Therefore, the celestial bodies originally planned to rush to Earth will go to other parts of the universe with artificial intervention. NASA believes that the success of this mission will be very important. One day in the future, if an asteroid really rushes to Earth, people have the ability to stop it and avoid disasters.
double asteroid redirection test
DART spacecraft was launched from the launch pad of the Vandenberg Space Base in California. After 10 months, a journey of 11 million kilometers was approaching the target of the impact. It is worth noting that the impact of this mission's asteroids does not pose any threat to the earth. They are far away from the earth and have no tendency to rush to the earth. Choosing them as the mission objects has also undergone a lot of screening to avoid other impacts caused by the failure of the mission. The
DART spacecraft weighs 550 kilograms and is composed of sensors, antennas, ion propellers and two 8.5-meter-long solar panels. It is in a cube shape. It collided with the asteroid "Dimorphos" (Dimorphos) with a width of 160 meters at a speed of 21,160 kilometers per hour, and disintegrated directly after the impact.
asteroid "Dimorphos" (Dimorphos) is moving around another asteroid with a width of 390 meters. The main purpose is to slow down the movement speed of "Dimorphos". If the asteroid's orbital speed can be slowed down by 73 seconds within 12 hours, NASA will officially determine that the mission is successful.
DART is equipped with Didymos reconnaissance and asteroid optical navigation cameras. The impact process was also recorded by the camera. At the same time, many photos of the impact were sent back to the earth one after another. At this moment, many astronomers are aiming at this asteroid, preparing to measure the brightness of the rock thrown after the collision and determine the degree of change in the orbit of the asteroid. Observatory on the ground and the sky in space Wen Telescope always monitors the results of this impact, which is a very important step for humans. In the future, we will know how much force it will take to shift the asteroids that rush to Earth.
planetary defense means
Internationally recognized planetary defense means are basically actively attacking to destroy the asteroid or deviate from its original orbit, such as nuclear explosions and kinetic energy. Impact, laser ablation, ion beam traction, gravitational drag, mass drive, etc. The United States' experiment this time belongs to the kinetic energy impact scheme. The biggest disadvantage of this solution is that it cannot effectively defend against large-sized asteroids under the conditions of short warning time.
China's leading global planetary defense research
Although the United States has taken the lead, China is also in the world's leading position in deflecting the asteroid trajectory through impact.Chinese scientists have proposed the concept of "striking stones with stones" enhanced kinetic energy impact planet defense mission, and by launching unmanned aerial vehicles to capture small-sized asteroids and combine them into impact bodies with the aircraft, and then knock the potentially threatened asteroid out of the orbit of the earth. This solution is better for orbital deviation and can effectively withstand large-sized asteroids. Not only that, the program requires lower costs and shorter preparation time.
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