Recent calculations of experts from NASA show that with probability 1 to 2700 in the Ground could hit a very large asteroid Bennu. This should happen in the next century. Experts believe that the consequences of a meeting with Benn can be very destructive — until the total destruction of life on Earth. In evaluating the possible risks, the researchers came to the conclusion that the safeguards for the protection of the planet from a collision there. According to experts, are developing at the moment ways to avoid meeting with an asteroid are not one hundred percent effective. Nevertheless, these developments are carried out.
Given that the power of the explosion at the moment of collision of an asteroid with the Earth may be of the order of 1200 megatons, which is roughly equivalent to 80 thousand bombs dropped on Hiroshima – it is quite understandable desire of NASA “perebdet, than nedobdet”.
According to experts, the fall of Bennu to Earth may occur on Sunday, September 25, 2135. Recently in the journal Acta Astronautica has published an article in which scientists shared ideas on how to avoid this catastrophic event.
“At the moment, the probability of falling of an asteroid on the Earth is quite weak, but the consequences, in the case of this fall will certainly be catastrophic for our planet,” explains Kirsten Hawley of Lawrence Livermore national laboratory and one of the members of the newly formed team of NASA planetary security.
“When we are a hundred percent it will become clear that the threat of the asteroid is really inevitable, then we would very much like to Land by this time was ready to repel this threat.”
The most promising concept of the reflectivity of asteroid threats, a draft of the spacecraft HAMMER (Hypervelocity Asteroid Mitigation Mission for Emergency Response). The device is provided to use either in the form of a thermonuclear charge, or as the shock of the projectile — in fact a battering RAM with which scientists could push Benn away from a dangerous trajectory.
At the moment the HAMMER is still only a concept. Presumably it will be a spacecraft weighing about 8 tons and a height of about 9 meters. For comparison, the width of the asteroid Bennu is more than 510 meters. The space rock weighs about 79 million tons, which is approximately 1664 times the weight of the Titanic. The launch of HAMMER proposed using Delta IV Heavy, which is the second payload carrier rocket in the world after the Falcon Heavy from SpaceX.
“Two realistic solutions to the situation that now under consideration, is the use of a spacecraft as a shock element or carrier for the delivery of nuclear explosives to deflect the approaching near — earth object,” say the authors in an article published in the journal Acta Astronautica.
The researchers note that it is extremely important to choose the most appropriate moment for the launch of the spacecraft. If you start to exercise too early, it will be difficult to predict how will behave the asteroid after impact. If you run it too late, the giant stone will be difficult to shift off course.
Hawley and her colleagues have done the calculations and found that for the success of the mission may require from 7 to 11 launch HAMMER, if the probable collision will remain for 25 years. If before the collision will remain about 10 years, the number of required runs can be increased to 53.
Scientists say that with each additional run will increase not only the chances of failure of each particular run, but the possibility of complete failure of the mission.
“In the case, when for successful reflection shot, you need multiple launches, the success of the mission becomes less optimistic due to the increasing chance of failure of failure of every single run,” says physicist Lawrence Livermore national laboratory Megan Brooke Forces.
Researchers believe that more preferably, the use of HAMMER in the form of the impactor, which was built in the path of the asteroid, will be able to push it in another direction and will not allow to reach the Ground. However, due to a number of uncertainties and small available reaction time, this method may be ineffective.
In this case, a more appropriate option, according to experts, will equip spacecraft’s HAMMER nuclear charge and its subsequent launch in the direction of Benn. The explosion, according to the researchers, will not destroy the asteroid, but it may push him from a dangerous path of rapprochement with the Earth. To detonate a nuclear charge is not offered on the asteroid itself (many are probably now thinking about kinoeye “Armageddon”), and in its immediate vicinity. In this case, one side of the asteroid are exposed to powerful radiation. Its matter starts to evaporate, and as a result, escaping from its surface gases will create the necessary traction for change in the direction of Benn.
Scientists say that there are too many uncertainties and probabilities to be able to talk about a more accurate outcome. In the end before a possible fall of the asteroid on the Earth we have more than 100 years. However, due to its orbit of Bennu every six years of fairly close passes by the Earth, so we have the ability to track changes in the trajectory of its movement. In addition, flying to the asteroid space probe OSIRIS-Rex. The purpose of the mission is closer to a space object and take samples of its soil for further study.
To date, astronomers had discovered more than 10,000 potentially hazardous near-earth objects. Not every one of them can be tracked as Benn, but nearly 2,500 of them have the same size. Experts predict that if even one of them will hit the Earth, for humanity, the consequences of this impact will be globally catastrophic.
Researchers estimate, to start the process of mass extinction on the planet is enough of a space rock about the size of 1 kilometer. Recall that the dinosaurs had to face the consequences of falling of asteroid with a size of about 10 kilometers.
An asteroid strike of any size would be disastrous if not for the entire planet, then at least for part of it. The key factor that will help us avoid this fate is our vigilance.
Experts say that in the scenario with the imminent threat of falling of an asteroid on the planet, we can reduce the consequences of at least one month before the event. But in this case we really have to act in the style of the movie “Armageddon” by running into the object of a very powerful nuclear device that will split the asteroid into many fragments. In this case, the damage will be due only to those of its fragments that overcome earth’s atmosphere and still will fall on the planet.
“Postponing the issue indefinitely may be the greatest enemy for the implementation of any mission to counter the asteroid threat. That is why today there is a need to start development platforms that will help us to deal with this threat in the future,” says Hawley.