Chelyabinsk: ten years after the impact, how capable are we of defending ourselves against asteroids?

Exactly 10 years ago, the February 15, 2013, an asteroid with a diameter of about 20 meters impacted our atmosphere and exploded shortly after over the Russian city of Chelyabinsk , releasing an amount of energy equal to that which would release about 30 bombs of the caliber of Hiroshima. The resulting shock wave caused about 1500 wounded, mostly hit by shards of glass from blasted windows. But there were also cases of burns and temporary blindness caused by the strong electromagnetic radiation emitted by the object which, before exploding, caught fire due to contact with atmospheric gases. He was called Chelyabinsk asteroid, from the name of the Russian city that suffered the main consequences. Given the recurrence, let’s see what are Esa’s plans (European Space Agency) and NASA (National Aeronautics and Space Administration) to avoid similar disasters in the future. But first we need to answer a question: why weren’t our detection systems able to warn us in time ten years ago?

Backlight

For two reasons. Today it is believed to have discovered about 95% of the asteroids (we are talking about the Neo, the Near-Earth Objects, or those that orbit near the Earth) with a diameter greater than 1 kilometer. In these terms, the Chelyabinsk asteroid was therefore a rather small object and therefore more difficult to locate. But the reason for the missed sighting was also another: the object it came in broad daylight from the direction where the sun was and was therefore “hidden” by its rays. And the detection of extraterrestrial objects that are backlit is not trivial even with the tools we have today, such as they explain the experts Inaf (National Institute of Astrophysics). This is why ESA plans to send a telescope for this function into space.

Neomir and Neo Surveyor

“Asteroids the size of the Chelyabinsk meteor – explains Richard Moissl, head of ESA planetary defense – they hit the Earth roughly every 50 to 100 years. Injuries caused by air blasts or similar events could be avoided if the public were informed of the imminent impact and its expected effects. With advance notice, local authorities may advise people to keep well away from windows and glass”. Neomirdesigned byHexis thought to be located in the Lagrange point “L1” between the Earth and the Sun. This would be an ideal observation point for objects coming from the direction of the Sun, those that, as we said, put the instruments currently available the most. In parallel, also the NASA is planning to launch a new “space vigilante”, the New Surveyor. Both Neomir and Neo Surveyor will use infrared telescopes to locate objects larger than 20 and 140 meters in diameter, respectively. Neo Surveyor is expected to launch in 2026while that of Neomir for the 2029-2030In accordance to Moissl told Space.com. “ESA’s next Neomir mission – concludes Moissl – it will detect asteroids like Chelyabinsk from the same region of the sky as the Sun, filling a vital gap in our current ability to predict and plan for dangerous impacts.”