The European Union is funding a study of three methods to divert the path of the celestial bodies that threaten our planet. The nightmare scenario of huge asteroid hit the Earth head above all the joy of science fiction writers in Hollywood. But if the odds of such a disaster are very low, the consequences are so high (destruction of an entire region or a country based on the size and speed of the fireball) that a small group of international scientists have launched a curriculum very seriously to try to avoid the impact of a “near-Earth bodies”, the 8,000 known asteroids and comets that periodically pass close to our planet.

The program NEOShield (shield against the acronym NEO) was funded by the European Union to the tune of 4 million over three and a half years and its organizers met for the first time this week in Berlin. “We will study in detail the three most promising methods to divert the path of dangerous objects,” says Michael Patrick, director of research at CNRS, specialist in asteroids at the Observatory of the Côte d’Azur in Nice. France is well represented in the program, with four of the 13 participating scientists.

The first method is very simple in principle: we send a space probe crash into the asteroid at high speed. In detail, the difficulties are many and will be thoroughly investigated. Asteroids and comets are in fact far from large compact blocks, but are mostly aggregates of very inhomogeneous rocks. “We’re going to run simulations with the physical mass complex enough to watch the response of an asteroid,” said Patrick Michel.

The automatic pilot of an object traveling at high speed into a small dark body is also far from clear, and will be carefully studied by the European manufacturers participating in the program. A mission called Don Quixote has been studied by European Space Agency (ESA) to demonstrate the feasibility of the technique.

The second method of deviation, called gravitational tractor, is indirect and requires no contact with the object of destination. Instead, we must maintain a spacecraft stationary as close as possible to the asteroid or comet, and this for several years, so that the mass of the vehicle attracts the body slightly dangerous and eventually change its trajectory.

A spaceship hyperfiable

The method is “soft” and works independently of the internal structure of the asteroid or a comet, but requires, however, to know its mass and have a space vehicle hyperfiable, able to operate autonomously for years. Even if the deviation is small it may be sufficient to prevent the Earth if applied soon enough. “A small angle deviation at the beginning can lead to major changes when the direction of extending millions of kilometers,” says Michael Patrick.

The last method is by far the most controversial and is to detonate a nuclear device near the NEO. This technique could be considered the last resort, both for a very large asteroid, over one kilometer long, is a dangerous object is detected too late to apply other methods.

Source: www.lefigaro.fr