, a "feat" occurred in the deep space of the universe, about 11 million kilometers away from the earth.
For the first time, human beings have changed the trajectory of an asteroid by taking the initiative to attack and using the impact of artificial spacecraft. Scientists hope that, starting from this, the potential fate of mankind will be changed. What is the relationship between
's impact on an asteroid and the fate of mankind? Let's talk about this issue of "Tianmu Tech+".
dinosaur data map. Source Xinhua News Agency
Everything has to do with a distant species - dinosaurs.
In the research on dinosaur species, there has always been a mainstream view. In a spring about 65 million years ago, an asteroid with a diameter of about 10 kilometers "hit" the earth, causing tsunamis, volcanic eruptions, and earthquakes. The earth's environment has undergone great changes, and finally the dinosaurs, the "overlord" of the earth at that time, went extinct.
are the same species of life on earth. Are humans facing the same threat as dinosaurs?
Avoid asteroids or the answer to the question.
DART package data map
As a result, NASA, in conjunction with the Johns Hopkins University Applied Physics Laboratory, launched a double asteroid redirection experiment, and designed a special asteroid to impact asteroids. spacecraft - DART.
According to the official website of the Johns Hopkins University Applied Physics Laboratory, the main structure of DART is 1.2 meters long, 1.3 meters high, and 1.3 meters high, and weighs about 570 kilograms, less than the weight of a car. half.
DART schematic
In order to fly autonomously, the DART is equipped with two large solar panels , which "armspan" when fully deployed, each panel is 8.5 meters long. The
DART is also equipped with an autonomous navigation system, equipped with an optical navigation camera to capture images of the impacted celestial body and guide the DART to impact.
DART also carries a "little assistant" - Cubestar LICIACube, which can be separated from DART and record the "beautiful shadow" at the moment of its impact.
DART, a schematic diagram of the comparison of the size of the double planet and the earth reference object
At 1:21 a.m. EST on November 24, 2021, DART was launched into space and ran towards the universe.
's target final point is about 11 million kilometers from Earth -- the equivalent of nearly 29 Earth-to-moon distances for a two-planet system. This distance is not far or near, and the artificial spacecraft can reach it smoothly without threatening the earth when it hits the asteroid. The larger of the two-planet system
is called Didymos, with a diameter of about 780 meters. The smaller one, called Dimorphos, was the real target of the DART strike. According to preliminary estimates, Dimorphos is about 163 meters in diameter and weighs 5 billion kilograms.
During the impact, DART gradually approached the binary star and identified smaller Dimorphos.
DART rushes to the double planet diagram
10 months after spaceflight, at 7:14 on September 27, with the countdown of "3, 2, 1", DART deliberately crashed into the small target at a speed of 6.2 km/s Planet, successfully completed the impact, like a golf cart crashed into the Pyramid of Khufu.
According to the results published on NASA's official website, the impact shortened the orbital velocity of the asteroid by 0.1%. That is, according to the original orbit, Dimorphos circles Didymos every 11 hours and 55 minutes. After impact, the period may change to 11 hours and 45 minutes. In the coming weeks, the research team will also measure and calculate the orbital changes more precisely.
Now, let's answer again, what's the use of this impact.
A large number of asteroids collide with the earth every year, most of which are decomposed in the earth's atmosphere, but some will "closely contact" the earth.
On February 15, 2013, a celestial object fell in Chelyabinsk, Russia. A meteorite with a mass of about 10 tons fell to the earth. When it passed through the atmosphere, it rubbed and burned, exploded, produced a large amount of debris, and caused injuries.
has media coverage, At present, humans have discovered more than 20,000 near-Earth asteroids, of which about one tenth is a potential threat to the earth.
In order to deal with the threat of asteroid impact, China is also actively taking action. On April 24 this year, Wu Yanhua, deputy director of the National Space Administration, disclosed to the outside world for the first time that my country will set up a near-Earth asteroid defense system to deal with the threat of near-Earth asteroid impacts and contribute to the protection of the earth and human security.
And when humans master the ability to change the trajectory of asteroids, if asteroids that threaten the Earth are discovered in the future, maybe we can avoid a potential fate like the dinosaurs.
(except for the dinosaur data map, the pictures and videos in the text are from NASA's official website)
