What science knows about an asteroid that comes closer to the Earth at Halloween – BBC

Asteroid-newsmaker

October 20 captured the theme of the world’s media convergence 2015 TB145 asteroid with the Earth. A huge number of publications – world news agencies, British newspapers with a centenary history and major TV channels – reported that on October 31, the day when the English-speaking world marks “diabolical holiday” Halloween close to Earth will fly relatively large – about a hundred meters – Asteroid . Some reports indicated that the occurrence of this asteroid was a complete surprise and that a celestial body is literally “came from nowhere”, as it has an abnormally high speed and unpredictable path.

Meanwhile, Asteroid 2015 TB145 was discovered by astronomers more October 10, 2015, as said in a statement on the website Jet Propulsion Laboratory (JPL) NASA .

The body was discovered the project Pan -STARRS, which is a network of four robots telescopes located in Hawaii. On account of Pan-STARRS – the opening of a huge number of asteroids, comets, and supernovae. Due to its location review allows the observer most of the sky and capture the vast majority of large asteroids that pass near the Earth.

According to the Circular site Minor Planet Center , the orbit of the object has a very large eccentricity (0.86 – that is, the asteroid has a very elongated orbit), as well as a large stab tilt (39.8 degrees) to the plane in which the Earth revolves around the sun.

Should we be afraid to Halloween?

According to the latest data, the asteroid will pass at a distance of 480,000 km from the Earth. That is, he did not even fall into the orbit of the Moon around the Earth (the average distance from the planet to its only natural satellite, as you know, 380 000 km). Even given the fact that the size of the asteroid is about 100 m, the object can not constitute a danger to the Earth. To verify this, do not need to write the formula of the gravitational interaction and write the equations that describe the tidal effects on the Earth other bodies. The diameter of the Moon – 1700 km, and it is seventeen thousand times larger than an asteroid.

Accordingly, the asteroid will cause on Earth tides that are 17 000 times smaller than the Moon tides.

Thus, the impact of an asteroid to Earth will be negligible, and talk, and the more afraid of some disasters in connection with the forthcoming 2015 TB145 is not just wrong and unscientific.

What about the meteorite Chelyabinsk?

Probably , Chelyabinsk residents might object to the author of these lines, accusing him of belittling the asteroid-comet hazard and recalling of injuries caused by falling to the ground in February 2013 a meteorite. But then it would be appropriate to recall that in the fall of the Chelyabinsk meteorite people received injuries that were caused by cuts to break away from the explosion of glass.

In this regard, it would be worth in the first place to teach people staying in the room, he saw a bright flash, do not run up to the window and seen what is it exploded.

The speed of light is 300 000 km / s, and the velocity of the shock wave in the medium – a hundred thousand – one million times lower. That is why, after a bright flash – whether it be a bomb or a meteorite fall – will almost certainly be followed by an explosion.

Of course, from the fall of such bodies as the Chelyabinsk meteorite, the Earth is not immune. And it is not very clear how to keep track of such bodies when they approach Earth from the sun. But on the other hand, it is still a fairly rare event, to think seriously about how to protect yourself from them, and spend the large sums. On the Earth itself have a lot more hazards – both natural and man-made. The most important thing is that as long as the history of mankind do not know a single case of loss of life fall to Earth asteroid or meteorite.