In 2020, an asteroid can fall to Earth
Dangerously approaching Earth of celestial bodies, mankind was frightened to trembling knees since ancient times. Do you remember? All these legends about the “red comet” that has drawn the sky, about “stones from the sky” and other passions ... It is sad that many do not bother to rise above the knowledge gained from ancient fairy tales, and do not even try to get acquainted with the view of modern science on the problem. But she has stepped forward in this matter.
Well, today we will give the floor to astrophysicists and try to find out everything we can on a popular level about asteroids. Including whether they are in danger of their fall in the near future, and what consequences such cases may have for our planet and ourselves, as well as news on the development of preventive measures to combat them.
Let's get acquainted: asteroids
So, asteroids are not planets yet, but they are no longer meteorites. They are much smaller than the first and do not differ in the correct form, besides they cannot have their own atmosphere. However, in space, they move in a heliocentric orbit (in our system).
According to the roughest highlights, given that only bodies larger than 30m can be explored in distant orbits, several hundred thousand asteroids continuously ply around our Sun. The largest of them, for example, Vesta, Ceres and Pallas, are named after their names, and not just cataloged by serial numbers, and are up to a thousand kilometers or more in diameter.
Most asteroids are not loners. They form several belts, the closest and largest of which is located between Mars and Jupiter.
Humanity began to study asteroids relatively recently - at the end of the 18th century, although they watched them, recorded cases of their close passages and falls to the Earth’s surface since ancient times. However, young civilizations did not separate asteroids separately - they were just “meteorites” or “comets”, “shooting stars”, like other smaller bodies.
Evidence of the fall of asteroids on our planet is very common. And there are many hypotheses that before these facts, if they concerned colossal-sized celestial bodies, became the cause of a number of significant catastrophes.
For example, it was one of them that once formed the Chiksulub crater 65 million years ago, and it is assumed that it was because of this that the dinosaurs became extinct. One can also recall the Eltanin disaster that occurred 2.2 million years ago, which caused kilometer-long tsunamis and significant geo-changes that interestingly shuffled the flora and fauna on our Earth.
Are asteroids dangerous? And, if so, how much?
Using computer modeling, modern physics has calculated the dependence of the diameter of the falling asteroid (X) on the degree of destruction and the severity of the consequences of this disaster:
- X <30 m = atomic bomb explosion;
- 50 m> X> 30 m - shock wave with destruction;
- X ≈ 50 m = by the force of the Tunguska disaster;
- X ≈ 100 m = explosion of a 50 megaton hydrogen bomb;
- X ≈ 200 m - a territory the size of an average state will perish;
- X ≈ 500 m - the whole continent will die;
- X ≈ 1000 m - billions of victims;
- X ≈ 5000 m - critical climate change;
- X> 10,000 m - the planet will be destroyed.
Of course, the fall of even thirty-meter bodies is rare for us. For comparison, recall that the relatively recent Chelyabinsk meteorite was 17 meters in diameter. Then, as we recall, in some places temporary structures collapsed and glass flew in the houses, and only a few residents received minor injuries.
Fight or put up?
But official science claims that in every century of the Earth’s existence, there are no less than a dozen incidents of relatively large (but not so much as to become a real catastrophe — we will consider these facts below) celestial bodies classified as asteroids. Mostly in desert locations. Meteor showers from every little thing - in general, the phenomenon is almost ordinary.
Of course, you shouldn’t definitely shrug off the threat of asteroid fall - it all depends on their size, chemical composition, and also how much they will be able to collapse, lose speed when entering the dense layers of our atmosphere.
And in order to know what exactly the scale of the event is coming, astronomers constantly monitor all potentially dangerous celestial bodies, keep their records in special tables in real time, assigning them one rating or another. As a result, there is a chance to notify mankind in advance of the expected disaster in order to have time for evacuation or for measures to directly affect the asteroid.
By the way, about the direct impact. Not so long ago, NASA and the European Space Agency organized a joint special mission, which is studying the current capabilities of terrestrial technologies to influence the trajectory of a particular asteroid. The invention of general methods and specific tests became possible after the recent completion of truly epoch-making work by a team of astrophysicists from the United Kingdom, who conducted a computer simulation of the behavior of 50 thousand asteroids and meteorites from 15 m in size - the closest and most risky ones to us.
The objectives of the study included the assessment of risks from a collision. Based on these data, in order to decrease the size of the threat, work has begun on the effects on the physics of the studied celestial bodies.
The first work of the special mission will be an experiment, just starting in 2020, when a pair of probes will be sent to Didim (780 m) and Didimuna (his companion - 170 m), which will have to ram the asteroid and track its trajectory: one device will be an impact force and the second is an experience recorder.
Even earlier, tests were begun on a nuclear explosion of celestial bodies, on their destruction by ion technologies. And at the end of 2019, a truck driver will be sent to the asteroid 2011 MD, which will stop its flight, take it with special probes, pack it in a special soft container and redirect it towards the moon for further safe moon landing. If the experiment succeeds, they will continue to investigate not only the packaging of relatively small bodies, but also the breaking off of large pieces with a repetition of all the described measures.
However, unfortunately, we are only talking about the tactical current tasks of combating asteroids that appear in the immediate vicinity of our planet. It is not possible to calculate and implement long-term projects, because, firstly, astronomical indicators of system objects are not in stasis - the error in calculating the trajectory over long periods of time is always very large.
And, secondly, we are not able to deal with threats at significant distances from the Earth, since flight technologies are not yet developed at this level. Although, the human space industry does not stand still, and who knows what tools we will have to deal with asteroids tomorrow?
What asteroids should we expect to see in 2020?
No matter how much experts at NASA and other major space agencies on the planet explain that asteroids are not bullies in city streets, they are ready at any moment to attack us from behind the gateway. Everything is tracked, calculated and known in advance. Even if an object fell into the red zone of threat, more than a dozen years pass, and there may be hundreds, depending on its orbit and speed, until it really falls on our heads.
However, from the “next visits” it is worth noting the date September 3, 2020, when 2016 NF23 (70 - 160 m) will pass 18 million km from the Earth - this is not a fall, of course, however, short-term weather anomalies, strong winds or storms can be expected. Prior to this, in April, much further than the first, but, nevertheless, the asteroid 2005 YU55 will appear, and on May 10, 2008 TZ3 will fly by at a distance of 7.28LD. And finally, on October 4, 2017 YD2 will appear.
In general, at the moment in our system there are about six thousand asteroids and other significant celestial bodies, whose trajectories at different points in time can approach the Earth at a distance of less than 1.3 AU
Well, knowledgeable, means armed. And, given the fact how actively they are currently working on near space exploration projects, how the relevant technologies are being improved and cheapened, every year there are less and less reasons to panic Earthlings.
The best minds and the most powerful space corporations are already assuring us that with a high degree of probability, even during the life of the modern generation, we will finally master and put on stream inventions that will help minimize threats from asteroid crash. But, of course, it is worthwhile to understand that for such ambitious goals, all of humanity must mobilize and join forces - for the benefit of us all.