June 30 marks the Day of the asteroid, designed to remind humanity of the need for joint efforts to prevent a collision of the Earth with asteroids.
65 million years ago, an asteroid 10-15 kilometers long, moving at a speed of 57 to 115 thousand km / h, crashed into the Earth. As a result of the collision, a 180-km-diameter crater formed in a few minutes, the earth’s surface melted, and huge mountain ranges rose. The explosion provoked the devastating megacunami, and solid debris fell to the surface of the earth in the form of a fiery rain. Dust has risen in the atmosphere, and the planet has become obscured for weeks, and maybe months. The fall of the asteroid led to a shallow-tertiary extinction. On Earth, 75% of all plant and animal species, including dinosaurs, were killed.
Astronomical and geological finds indicate that the repetition of such events is only a matter of time. Maybe not tomorrow or the next two hundred years, but it will definitely happen. In this regard, some astronomers fear that mankind does not make sufficient efforts to avoid the impending catastrophe. The day of the asteroid (“Asteroid Day”), celebrated on June 30, is an international information campaign aimed at highlighting the problems and threats looming over the planet. Last year, the UN declared Asteroid Day international. On this day, 700 events are held in 190 countries, meetings are held with the participation of experts and scientists, which can be watched live. Channel Discovery Channel will show a series of thematic documentary films, as well as the premiere of the film “How to survive with the fall of an asteroid”, in the production of which the activists of the information campaign took part.
Here is a fragment of the speech of one of the popularizers of the day of the asteroid, NASA astronaut, former Apollo program participant, Rusty Schweickart (Rusty Schweickart) on the Discovery Channel: “That night thousands of beats hit the planet. Every day 100 tons of asteroids fall to Earth. Most of them are the size of a grain or pebble, and only two or three bodies the size of a soccer ball. The most dangerous thing is that a larger body can fall on us, and then huge destruction will take place on Earth. And it’s just a matter of time. ”
In addition to the threat of the fall of huge asteroids, capable of destroying humanity, the initiators of the company warn of the real danger posed by more modest objects. The diameter of these bodies is tens and hundreds of meters, and they rotate in large numbers on the orbits closest to Earth. As a result of a collision with one of such objects, entire cities or even regions may be destroyed.
Here is a fresh example. A meteorite 17 meters in diameter, which fell in Chelyabinsk on February 15, 2013, provoked an explosion in power 35 times greater than a bomb dropped on Hiroshima. This fragment, discovered by scientists only after entering the atmosphere of the Earth, has turned into a real fire shell. Fortunately, this object consisted of a not very dense substance, so the car exploded in the air and did not cause serious damage on the ground. However, the explosion damaged 7,200 buildings in six cities, and 1,500 people were injured. In the main, injured people who stood at the time of the explosion at the window, to better consider what is happening.
At the beginning of the last century, a larger object caused even greater destruction. It’s about the Tunguska meteorite. June 30, 1908, the object, a diameter of different data from 30 to 50 meters, destroyed a total of 2 thousand square kilometers of Siberian taiga, or 80 million trees. Now this date is celebrated as the Day of the asteroid. The explosion in the capacity of 1,000 bombs dropped on Hiroshima occurred over a deserted territory. But what would be the consequences, drop an asteroid in a densely populated area?
Have the opportunity to prepare
Fortunately, space agencies are able to develop technologies to change the trajectory of objects of this size, and astronomers have the tools necessary for timely detection of the threat. However, scientists need broad public support and adequate funding.
“Unlike earthquakes, tsunamis or hurricanes, a collision with an asteroid is one of disasters that can be prevented,” says astrophysicist Hakeem Oluseyi, one of the popularizers of the Day of the asteroid. “With appropriate training, future collisions can be predicted.”
Unfortunately, the problems of collision with asteroids are not among the priorities of any serious organization. In December 2016, members of the European Space Agency (ESA) did not approve funding for the “Asteroid Impact Mission” (AIM) mission, which involved the development of a program to test technology for changing the trajectory of asteroids in cooperation with NASA. Preference was given to the mission to explore Mars “ExoMars”. Every day, astronomers discover new space debris near the Earth, but the rate of detection is very low.
If there is obvious evidence of the destructive power of asteroids and technology is being developed that will prevent future collisions, why is this problem not taken seriously?
Debbie Lewis, an expert on emergencies and threats, the popularizer of the Day of the asteroid, believes that the main reason is that these events usually do not have eyewitnesses. “We all know what tornadoes are, floods, hurricanes or earthquakes, because these events happen in everyone’s life.” She agrees with Shwaikart, who believes that “not every person in his life can witness the fall of a large asteroid.” If there are no witnesses, then the phenomenon itself does not exist.
See to believe
Large telescopes convince us of the opposite. With the naked eye on the surface of the Moon, you can see traces of the fall of asteroids over the past 4 billion years. On Earth such traces are hidden as a result of movement of tectonic plates. In 2009, astronomers witnessed a powerful collision of the comet Shoemaker-Levy 9 with the planet Jupiter. As a result of the collision, a spot on the turbulent surface of the planet was formed for several weeks, exceeding the size of the Earth. And what about on Earth? Between 1994 and 2013, 556 fireballs, as well as flares and fireballs, were formed in the earth’s atmosphere as a result of the fall of asteroids from one to 20 meters in size.
But what happens outside the Earth? It is believed that scientists found only one-hundredth of all asteroids of the solar system (fortunately, this is 90 percent of the largest asteroids). In addition, the greater part is located at a great distance – in the Kuiper belt or further, as well as in the asteroid belt, a large accumulation of debris between the orbits of Mars and the giant Jupiter. These fragments do not pose a serious threat to our planet.
But the situation can change if these asteroids or comets under solar gravity approach less than 1.3 astronomical units (au) to the Earth (au is the distance from the Sun to our planet). Such objects are included in the category “Near-Earth Objects” (NEOs). Bodies reaching 150 meters in length and approaching the Earth at a distance of less than 7.5 million kilometers (for comparison, the minimum distance from Earth to Mars is 53 million kilometers) are considered potentially hazardous objects (VET). On average, only 4% of NEOs are potentially dangerous objects.
Observation of the sky
Just in case, astronomers are constantly in search of luminous objects in the sky, which can turn out to be Astroid or comets heading to Earth. Thanks to this work, carried out by numerous observatories on earth and in space, among which “De Cam Neo Survey”, “NEOWISE”, and “Catalina Sky Survey”, only 1,500 NEOs were opened in 2015. But this may not be enough.
“Thousands of astronomers are observing every night,” Shweikart says. “But we need more equipment in order to predict a dangerous collision, and for this we need to locate about 10 million objects.” How many remains to find? At the moment, scientists have localized about 16,300 NEOs.
In this regard, the organizers of the Day of the Asteroid made up the “100X declaration”, which says about the need to achieve a hundredfold increase in the number of localized asteroids. Astrophysicist Hakeem Oluseyi believes that at the moment there are three ways to achieve this: using optical telescopes, radio telescopes and space infrared telescopes.
In turn, the White House in 2016 announced its goal to bring the percentage of open asteroids larger than 140 meters to 90%. According to the report on the strategy of national preparation for the attacks of the OZ, at the moment 28% of the bodies are open. “The power of the explosion in the collision of these objects with the Earth is equivalent to 60 megatons, which exceeds the amount of energy released by testing the most powerful atomic bomb ever tested on Earth (the Tsar bomb of 50 megatons).” Such a collision can lead to local destruction.
300 thousand objects longer than 40 meters
According to the Jet Propulsion Laboratory (JPL), in addition to objects a few hundred meters in size, not yet discovered about 10 million bodies with a diameter of more than 20 meters, as well as about 300,000 over 40 meters in length. Such objects are capable of destroying entire cities.
The degree of danger (can collide with the surface, can cause damage, can lead to destruction) is an important characteristic in the estimation of asteroids. Usually, when a new OZS is opened, almost nothing is known about this object, and only after a few months or even years of observation do scientists begin to determine its characteristics. Only in this way can you know its size, shape, mass, chemical composition, exact orbit and possible angle of collision. All these factors are very important for predicting the trajectory of an object and possible threats.
From the explanations of Rusty Shvaykart and the statements of expert Don Yeomans: “To protect the planet from a collision with asteroids, you need only three things: quickly detect them, quickly detect them and quickly detect them.”
As ABC told Michael Küppers, a research fellow at the European Space Agency (ESA), an AIM project participant, “a 10 to 15-year reserve is needed to have time to change the trajectory of an asteroid, although this depends on many factors.” Therefore, it is very important to discover these objects in advance in order to be able to send missions in the future to change their trajectories. Coopers also acknowledged that there is a danger of penetration of objects from beyond the boundaries of the solar system. The asteroid can pass near the Sun and remain unnoticed. This facility may take just a few months to reach Earth, and it will be very difficult to avoid a collision with it.
Spacecraft and atomic bombs to change the trajectory of asteroids
Now there are several theoretical technologies for changing the trajectory of the motion of asteroids. A gravitational attractor is the way in which a large spacecraft uses its engines and its own gravity to gradually change the course of the asteroid. Kinetic ram is a controlled collision at high speed of spacecraft with an asteroid, which leads to a displacement of the trajectory of the fragment. Laser ablation – the use of light pulses to affect the surface of the asteroid, resulting in the formation of steam jets and particles that can change the orbit of the body. As a last resort, the possibility of using a nuclear charge is being considered. This is the only way to destroy or reject a large object, but as a result, many small fragments can form, and there will also be no possibility to slow down large fragments.
Every year in the atmosphere one an asteroid the size of a car burns down, turning into a fireball. Once in 100-1000 years, an object the size of a football field, capable of destroying an entire city, falls onto the Earth. With an interval of several thousand years, an asteroid arrives capable of destroying the territory of the average state. It was such an asteroid that fell in Southeast Asia 700 thousand years ago. Approximately once every 10 million years there is a collision with an object a few kilometers long. If such an asteroid fell right now, it could destroy all of humanity or lead to multi-million victims.
Such phenomena occur very rarely, so at the moment no deaths have been recorded due to the fall of the meteorite. Compared to these space debris, environmental pollution, harmful emissions or vehicular traffic are more tangible threats. However, this is a real threat, warns us the popularizers of the Day of the asteroid.
“I think it’s extremely important for people to understand the importance of this for each of us, not just for politicians, scientists, engineers or people involved in this project,” says filmmaker Greg Richter, one of the Participants in the campaign Day of the asteroid. “We must do this for the sake of our planet and for the sake of our species.” To this end, in his opinion, it is necessary to attract broad public attention to this issue. Economic costs for this project will not exceed the amount allocated to other scientific projects.
“For me it’s like car insurance. Many people drive a car and admit that sooner or later they will get into an accident, “Shvaykart concluded. “We do not want to worry about this, we want to pay for insurance. (…) Now we need insurance to be able to find and change the trajectories of these objects. In the future, when this moment comes, we can save human lives. That’s all. We can connect the whole planet to this activity, if people pay attention to this topic. I hope that thanks to Asteroid Day people will be able to get enough information, and help their political leaders make the right decisions. ”
As with other global challenges, such as climate change or poverty, solving the problem of a collision with a large asteroid is perhaps another chance to prove that humanity can join forces for the welfare of future generations. Alternatively, you can cross your fingers and pray that this catastrophe does not happen while our civilization exists.
