Past events that have devastated the world have brought about changes from volcanic eruptions, to slow-forming climate change, to atmospheric composition. However, asteroid impacting Earth will bring more rapid destruction.
While large asteroid impact events occur rarely, smaller asteroid impact events occur much more frequently. According to nasa, Earth is hit by an average of 100 tons of space dust every day, and small asteroids (which are about the size of a car) enter the Earth's atmosphere every year. Fortunately, the vast majority of such rocks burn up before they hit the ground. But occasionally our planet gets hit by bigger objects.
The extent to which a larger asteroid can cause damage depends on a variety of factors, including the speed and angle of the impact, but even if an asteroid with a width of just 225 meters lands in rural and uninhabited areas, it is thought that the force is still enough to break windows, emit extremely bright light and cause instant sunburn. A rock the size of a house can strike and explode on Earth, with the power of a nuclear bomb, while a meteorite the size of a football field hits Earth about once every 2,000 years. However, for an asteroid to truly threaten the entire planet, it must be at least one kilometer in diameter.
Fortunately, it's rare for rocks of this size to hit us, but that's not to say that there aren't thousands of asteroids in the vast solar system large enough to cause such problems. In fact, the width of 1 km is actually quite small compared to some rocks hidden in the asteroid belt, for example, in the asteroid belt, the diameter of the rock can reach 900 km or even more. To the best of our knowledge, we've never suffered such a massive impact, but the most famous asteroid impact in history occurred about 66 million years ago through the Chicxulub Impactor.
Many believe that a deadly meteorite with a diameter of more than 10 kilometers triggered the mass extinction of the Cretaceous-Paleogene (K-Pg) event, which caused the extinction of the dinosaurs. There is no definitive study showing that such a massive strike will occur again in a short period of time, but such a major event does occur — theoretically, such a major event can happen at any time if the existence of an asteroid is ignored. But did such a major event really happen? Surprisingly, it did happen. For example, in the summer of 2019, we passed by an asteroid called "2019 OK.".
Without any warning, the football field-sized meteorite flew over the right side of the earth. "2019 OK" is less than 70,000 kilometers from Earth, which means that its diameter is less than one-fifth of the distance between Earth and Moon. This may seem like a long distance, but from a cosmological point of view, it happens near The Earth. In fact, it's the largest asteroid that has passed through Earth in a century, but we only discovered it when it flew over Earth that day.
Assuming that "2019 OK" deviates from orbit and flies toward Earth, its impact on Earth will destroy an area within a range of at least 80 kilometers. In general, the National Aeronautics and Space Administration (NASA) and other space agencies around the world are familiar with such events. At any given time, they would track thousands of asteroids that flew through space. Of course, there are also some fish that have slipped through the net. But for the most part, we've figured out the most threatening planets in the universe, and we've calculated the likelihood that they'll hit Earth. Warning: The way asteroids are named isn't exactly what you call "creative."
One of the asteroids most threatening to Earth is named "(85713) 1998 SS 49". This unique asteroid is part of the Apollo group, and the asteroid group is expected to pass through the Earth's orbit several times in the future, and this asteroid "(85713) 1998 SS 49" is likely to be closer to Earth than the moon, about 344,000 kilometers. Although it is about 3 kilometers smaller in diameter than the Chixulub impactor, it can still cause significant damage even if it deviates from its orbit and hits the Earth.
Interestingly, "(85713) 1998 SS 49 " is also expected to pass through Mars and Venus, making it a multi-planetary threat – although so far there is no conclusive evidence of collisions. Compared to planets and moons, these asteroids have low reflectivity and relatively small volume, making it difficult to track these objects accurately. But there's a reason this group of asteroids is listed as PHA (potentially dangerous asteroids) because researchers believe they have the potential to change direction and become more threatening than they are now.
No matter how tricky it is to track down asteroids, scientists are trying to track them as much as they can!
4179 Tuttatis is a potentially dangerous asteroid. It is predicted to be one of the largest and deadliest asteroids passing through Earth, with a diameter of five kilometers. If it hits Earth, it's huge enough to kill most of the creatures on Earth and trigger the effects of globalization. The asteroid's unpredictable orbit makes it infamous, meaning it is difficult to predict its position. It is a frequent visitor to special areas of the solar system and has already passed by the Earth in various close proximity. In 2012, it flew within eighteen months of Earth. We are expected to meet it again in 2069, but the distance between us will be one-half of the last one. If this prediction is confirmed. Will we be safe and sound? But if its trajectory proves to be more fickle than we thought, the outcome could be different.
(533319) 1999 JM 8 is one of the most famous asteroids predicted to crash into Earth. Seven thousand meters in diameter, it was only slightly smaller than the one that destroyed the dinosaurs. It is another frequent traveler flying near Earth, having flown by at least five times in the last century in an area 0.2 astronomical units from Earth. It is expected to meet Earth at a similar distance in 2075.
JM 8 is an extremely dim, low-reflective, and chaotically orbiting asteroid that is difficult to track with telescopes. Maybe one day it will fly by us and we don't know it. If he hadn't flown by our side and collided with us, our planet could have gone into the end of the world and a radical ecological adjustment.
But importantly, not a single asteroid actually collided with Earth as expected but missed it. Now, their orbits are still changing, and we track them as potential threats, but that doesn't mean they're going to bump into us, it's just that they change orbits, they may violate their prophecy and fly directly at us, and they all have the potential to cause chaos in the world.
Asteroid 4179
Asteroid 4179 (4179 Toutatis) is an Apollo-type asteroid discovered by Christian Bolas on January 4, 1989, and the Elinda family, which orbits through the asteroid.
At 6:40 GMT on December 12, 2012 (around 14:40 Beijing time), asteroid 4179 flew at a speed of 35,000 kilometers per hour at a distance of 6.9 million kilometers from Earth.
There are more than 6,000 near-Earth asteroids in the solar system, more than 1,000 pose a threat to the Earth, also known as PHA, and the distance between the near-Earth asteroid and the Earth also has a 'warning line', which is 0.01 astronomical units, that is, 1.5 million kilometers. There are some asteroids that can be observed, and some that are not observed, and there will be "emergencies" that break into the (line of sight).
By：。 , Zeng Yanling Jenny, Ye Seventeen