Astronomers are looking for ways to divert such bodies from their orbit The approach of an unknown asteroid, which threatened the Earth
The great danger from the direction of the sun
The diagram illustrates the distance that the asteroid - the space rock - passed by the Earth: only one third of our distance from the Moon.
Two weeks ago, on June 17, the astronomers breathed a sigh of relief. An asteroid, a huge block of rock originating in space, about 100 meters long (the length of a football field), came as close as 120 thousand km from the Earth - but "at the last moment" changed course and returned to the depths of space.
Although this time the Earth was saved from a blow that could have been very painful and destructive - it became clear once again that the plans for mapping these dangers from space do not cover all possible angles of impact.
The asteroid marked 2002MN was discovered only after it passed by the Earth, since it came to us from the direction of the Sun and was not detected before, but only three days later.
The mass of his body, the scientists assume based on their calculations, was about half a million tons. Its relative speed (between its movement and the rotation of the earth) when it passed by us was about 10 km per second. The energy that this movement carries is equivalent to a large hydrogen bomb (several megatons). The way the asteroid hits and its scope depend on the density of the rocky material and the process of its penetration into the atmosphere.
In history, two cases of similar bodies that hit the Earth are known: in 1908, an asteroid hit the Tanguska Valley region in Siberia. It exploded a few kilometers above the ground. The fireball from the massive explosion destroyed forests within a radius of several kilometers from the impact site. Many animals in the environment were also exterminated.
Another event: about 20 thousand years ago, a similar and much denser body hit, in Arizona in the USA, creating a crater 1 km in diameter and several hundred meters deep.
Studies that attempt to map the population of bodies that threaten the earth, focus, for reasons of convenience, only on those that arrive in the opposite direction to the sun. Now an Israeli research group is proposing to start tracking bodies that are between us and the sun - such as the one that has just approached.
Only more focused studies will successfully map the population of threatening asteroids and provide an opportunity to thwart such a threat, coming from the direction of the Sun (and therefore hidden from view). Recently, when an asteroid was identified for which a non-negligible possibility of impact was calculated
On Earth, a new method was proposed to divert it from its orbit. For the 1950DA asteroid, the study determined a 1 in 300 chance of a direct impact on the Earth, which was calculated to occur on March 16, 2880. The determination was based on the calculation of its trajectory in space and the assumption that it rotates around itself at a certain rate and direction of its self-rotation axis - but these details are still are unknown and there is an assumption that the manner of its progress in space is influenced by the sun.
The Russian scientist Yarkovsky claims in this regard that non-uniform heating of any body is able, over time, to change its orbit around the sun. The longer the non-uniform heating lasts - the greater its cumulative effect.
Hence his conclusion: it is enough to "paint" one side of an asteroid a different color from the color on the other side, so that the heating in the sun will not be uniform and thus its orbit around the sun will change. Maybe in a few years, based on this theoretical idea, they will start sending paint containers to the threatening asteroids, to prevent their future impact on the Earth.
Dr. Noah Brosh
Another asteroid misses the earth
01/04/2002
This is the crater created by a meteor in Arizona - 20 thousand years ago. The celestial body that hit the ground was about 50 meters in diameter. The diameter of the crater is more than 1 km, and its depth is several hundred meters
Dr. Noah Brosh
Fortunately for the Earth's inhabitants - it was a "miss". but
The incident is now being investigated
to the details because of its other implications. celestial body, asteroid,
whose size was less than 100 meters, passed at a distance of only 460,000 km from us, in its movement around the sun. If it had collided in Israel - a phenomenon similar to a nuclear explosion with a power of 4 megatons (four million tons of explosive material) would have occurred - 200 times the power of the atomic bomb that was dropped on Hiroshima.
Such an injury could have completely destroyed a large city, and caused significant damage to a small country.
The alarming thing about the event that occurred in early March is that there was no way to discover the threatening body, before it reached the dangerous proximity: it emerged into the Earth's environment from the direction of the Sun.
The special celestial body that passed in our very close vicinity (in astronomical terms) received the designation 2002-EM7. It was discovered by an American surveillance system, which is looking for threatening asteroids.
Asteroids are rocks that orbit the sun in different orbits. The largest among them have a diameter of several hundred kilometers, but they are rare, and are usually concentrated in the "asteroid belt", beyond the orbit of the planet Mars.
In contrast, hundreds of bodies with diameters between XNUMX km and less are known today, and some of them come very close to the Earth. The problem with the current search methods is that they are based on astronomical photography, which is carried out at night. Therefore, it is not possible to discover bodies that reach us from the direction of the sun.
To search for them in daylight, a radar is needed - however the existing facilities are limited to search distances close to their transmission power. The discovery of 2002-EM7 highlighted a flaw in conventional tracking methods. Although the searches
After bodies that threaten the sky are carried out in several observatories - and manage to discover quite a few such bodies - there are still "hidden corners" in the sky, from where "serious trouble" can emerge.
The good news about 2002-EM7 is that in the coming decades it will not threaten us again - this was its closest approach, so far.
Another near collision
Avi Blizovsky, 1/9/2000
On September 1, the threat to the Earth from large asteroids about to fall on its surface was illustrated again. An asteroid with a diameter of half a kilometer that was discovered only a few days earlier, on August 26, passed the surface of the Earth at a distance equal to 12 times the distance between us and the Moon, a distance so small that the scientists of the American space agency, NASA, defined the event as "almost a collision ". NASA personnel, who monitor asteroids and comets approaching the Earth, noted, however, that this time there was no real danger of impact. And yet, the great proximity of the asteroid allowed researchers to get a better idea of the nature of the celestial body. The asteroid QW7 2000, moving at high speed, even excelled in extraordinary brightness; It could also be viewed with a large amateur telescope.
266 asteroids are currently defined as having the potential to collide with Earth, and all of them are constantly being tracked. They move through space in different trajectories, but not one of them is marked as an immediate threat to world peace. However, the scientists warn, the possibility of a giant asteroid hitting the Earth and wreaking considerable destruction exists all the time.
British scientists now claim that it is time to take measures to protect the Earth from an asteroid strike. "These strikes do not occur with great frequency, but their consequences are severe," said Professor David Williams, former president of the Royal Astronomical Society. "Although the chance of this threat materializing is very small, the threat is tangible and we must do something about it." Williams said these things at a press conference in September, in which a report was published recommending measures be taken to reduce the chances of a collision that could cause the death of millions of people. The group that published the report was appointed by the British science minister, Lord Sainsbury, in January.
Williams and other members of the group dealing with near-Earth objects urged the UK to lead an international effort to track and monitor comets and asteroids, to reduce the chance of a fatal collision. know about their existence," said Dr. Harry Atkinson, the chief scientist in the research group.
At the heart of the early warning system, a telescope will be built in the southern hemisphere of the Earth, and will examine smaller objects than are usually observed by other telescopes. The cost of building such a telescope is estimated at 21 million dollars. The cost of the entire project, which will include additional telescopes, space missions and the construction of a tracking and protection system for asteroids, could reach billions of dollars.
The size of objects close to the Earth ranges from a pebble to something similar to a mountain. The larger the object, the less likely it will collide with the Earth, but when an asteroid with a diameter of XNUMX km collides with the Earth, it can cause the destruction of a quarter of the world's population. The warning system can allow scientists to track the asteroids, and if there is a fear of a collision, it will be possible to evacuate populations from the presumed collision site or divert the asteroid from its orbit using a missile.
Another asteroid misses the earth
01/04/2002
This is the crater created by a meteor in Arizona - 20 thousand years ago. The celestial body that hit the ground was about 50 meters in diameter. The diameter of the crater is more than 1 km, and its depth is several hundred meters
Dr. Noah Brosh
Fortunately for the Earth's inhabitants - it was a "miss". but
The incident is now being investigated
to the details because of its other implications. celestial body, asteroid,
whose size was less than 100 meters, passed at a distance of only 460,000 km
from us, in its movement around the sun. If he had collided in Israel - it would have happened
A phenomenon similar to a nuclear explosion with a power of 4 megatons (four
million tons of explosive material) - 200 times the power of the dropped atomic bomb
on Hiroshima.
Such an injury could have completely destroyed a large city, and caused damage
Significant for a small country.
The worrying thing about the incident that happened in early March is that there was no way to find out
the threatening body, before it reached the dangerous proximity: it emerged into the environment
Earth from the direction of the sun.
The special celestial body that passed in our very close environment (in terms
Astronomical) received the designation 2002-EM7. It was discovered by a system
American tracker, looking for asteroids
threatening
Asteroids are rocks that orbit the sun in different orbits. for adults
Between them a diameter of several hundred kilometers, but these are rare, and usually concentrated
In the "asteroid belt", beyond the orbit of the planet Mars.
In contrast, hundreds of bodies with a diameter between XNUMX km and less are known today,
And some of them come very close to the Earth. The problem with the search methods
The current one is that they are based on astronomical photography, which is carried out at night.
Therefore, it is not possible to discover bodies that reach us from the direction of the sun.
To search for them in daylight, a radar is needed - but the existing facilities
are limited to search distances close to their transmission power.
The discovery of 2002-EM7 highlighted a flaw in conventional tracking methods.
Although the searches
Searching for threatening celestial bodies is carried out in several observatories -
and manage to discover quite a few such bodies - there are still "hidden corners"
In the sky, from there "serious trouble" can emerge.
The good news about 2002-EM7 is that for the next few decades it won't
He will threaten us again - this was his closest approach, by the hour.
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