According to statistics, the chances that you will die from an asteroid fall are much lower than the chance of being killed by lightning. From time to time, space cobblestones approach our planet, but in the overwhelming majority of cases, everything ends well - asteroids simply fly by a few hundred thousand kilometers from Earth. Still, our planet against the backdrop of endless space is too small a target for accurate strikes.
Space agencies around the world conduct daily monitoring of near-Earth objects and can provide early warning of possible collisions. Nevertheless, there are times when a dangerous rapprochement is inevitable, but this becomes known literally a few hours before the likely event. There have been at least two similar incidents this year. The first occurred in April, the second - quite recently, in early June. In both cases, the emergence of a cosmic threat was a real surprise for scientists. Fortunately, both stones turned out to be relatively small, about 140 meters in diameter (such asteroids are officially recognized as potentially dangerous).
NASA's aerospace agency is not happy with this state of affairs, so it has developed a strategic plan to repel asteroid threats with several other US federal agencies. The team, dubbed the Interagency Working Group for Detecting and Mitigating the Impact of Earth-bound Near-Earth Objects (DAMIEN), recently presented a 20-page report that describes potentially hazardous asteroids, as well as some possible options for reducing asteroid threats for the next decade.
“The country already possesses significant scientific, technical and operational capabilities to prevent asteroid threats. The approval of a special training plan to counter potential threats from near-Earth objects will significantly increase the readiness of our country and international partners to effectively respond to these threats,”said NASA planetary defense officer Lindley Johnson.
The new plan builds on the list of strategic objectives presented back in 2016. One of the described problems requiring a solution is the low efficiency in detecting near-Earth objects. We have already mentioned two cases when NASA missed potentially dangerous asteroids literally under its nose. This is also attributed to the low efficiency of programs for the further observation of these objects.
At the moment, scientists know about the existence of about 8000 potentially dangerous near-earth objects, but according to experts, this is only a third of the real number of objects that are actually located there and pose a potential threat to our planet.
"According to the 2017 report, based on our current technical capabilities, only half of the total number of near-Earth objects with a diameter of 140 meters or more will be discovered by 2033," the new document says.
The newly formed group of technical specialists adequately assessed the existing problem and is currently working on solving issues that will allow reaching a new level of efficiency in the search and tracking of dangerous near-Earth objects.
Promotional video:
“If a real threat arises, we will be ready to jointly discuss the available information, work out options for its solution and transfer this data to people who will make the final decisions,” Johnson said during a press conference presenting the report.
This is only the first point of five that is described in the prepared document. The other two talk about the need to improve the quality of threat modeling and forecasting, as well as create a platform for international cooperation in addressing these issues.
There is also a clause here that describes a plan of action in the event that the detected object poses not a theoretical, but a direct, imminent threat. In other words, it is about how to ward off asteroids that will take a direct course to Earth. NASA has several proposals in this case. The agency developed some of them earlier. And not without reason. For example, according to the latest forecasts, with a probability of 1 in 2700 in 2135, the 492-meter asteroid Bennu may fall to Earth.
As one of the options for countermeasures, it is proposed to blow up this asteroid with a nuclear missile. Even if the nuclear charge could not destroy the Bennu, the shock wave, according to scientists, could push the space block from the dangerous trajectory of approaching the Earth. Another option is the use of a so-called strike spacecraft.
NASA is set to conduct the first tests of the asteroid deflection method in the 2020s with the launch of the Double Asteroid Redirection Test (DART) mission. Within its framework, it is proposed to send an impact spacecraft weighing 500 kilograms towards the asteroid "Didim". After completing the first part of the scientific mission to explore the near-Earth asteroid "Orpheus", the impact probe will go to its main target. Moving at a speed of about 6 km / s and hitting the asteroid "Didim", the device will be able to slightly shift the direction of motion of the asteroid, as well as its speed, by about 0.4 mm / s. Despite such a modest figure, in the longer term, this will significantly change the trajectory of its movement.
Also, in the future, to repel asteroid threats, it is proposed to use nuclear charges for the partial destruction of objects into smaller fragments that will become less dangerous. And among the alternatives, there is a proposal for the use of large "gravitational spaceships" that could use gravity tug technology and steer objects from a dangerous trajectory.
Further development of preliminary designs for asteroid deflection missions, as well as the construction and testing of systems on safe near-Earth objects, will be carried out by the NASA aerospace agency in conjunction with the National Nuclear Security Administration and the US Department of Defense.
The last part of the NASA report is devoted to a description of possible further actions in the worst-case scenario, when it will be impossible to deflect or destroy the asteroid threat heading towards Earth.
Nikolay Khizhnyak