New way to deflect asteroids in the offing

Scientists are developing a way to deflect asteroids that are on the path to collide with the Earth, by studying the asteroid Chelyabinsk which exploded over Russian skies in 2013.
The study, led by National Research Council (CSIC) in Spain, provides information on the effects a projectile impact would have on an asteroid.
The research focuses on the study of the asteroid Chelyabinsk, which exploded over Russian skies in 2013 after passing through the atmosphere.
The probability that a kilometre-sized asteroid could have devastating consequences after impact with the Earth is statistically small.
However, objects a few tens of meters across reach the Earth's atmosphere far more frequently.

The results indicate that the composition, internal structure, density and other physical properties of the asteroid are fundamental in determining the success of a mission that launches a kinetic projectile to deflect the orbit of a dangerous asteroid.

On February 15 in 2013, an asteroid with a diameter of about 18 metres exploded over the Russian town of Cheliabinsk, producing thousands of meteorites that fell to Earth.
The fragmentation of this object in the atmosphere illustrates the principle that Earth's atmosphere acts as an efficient shield, even though more than a thousand meteorites hit the ground, each with a total mass exceeding one tonne.

Despite the asteroid's small size, the shock wave it produced when penetrating the atmosphere at hypersonic speed caused hundreds of injuries and considerable material damage.
"Studying the chemical and mineralogical composition of the Chelyabinsk meteorite allows us to grasp the importance of the collision compaction processes that asteroids suffer as they near the Earth," said CSIC researcher Josep Maria Trigo of the Institute of Space Sciences.
"The results of this work are extremely relevant for a possible mission in which we want to efficiently deflect an asteroid which is close to Earth," said Maria Trigo.
Thus, following rigorous and systematic work, the new study has discovered the properties of the materials that the asteroid is made of.

In particular, the hardness, elasticity and fracture resistance, which could all be determinants for the success of a kinetic projectile attempting to deflect an asteroid's orbit.
The Chelyabinsk meteorite belongs to a group known as ordinary chondrites. The researchers chose it because it was considered representative of the most potentially dangerous asteroids in terms of its component materials.
Potentially hazardous asteroids that threaten the Earth suffer many collisions before reaching our planet; therefore, their consistency increases and their minerals appear battered.
The study was published in The Astrophysical Journal.