February 26, 2024

The Sun’s Invisible Asteroids: Planetary Defense a Decade After Chelyabinsk

Vapor cloud path left by the Chelyabinsk asteroid as seen by M. Ahmetvaleev on February 15, 2013. The small asteroid took off at a height of about 30 km, generating a brilliant, hot surge with a gas cloud, as well as a big shock wave that broke windows and knocked down parts of buildings and structures. Of course, there is also the risk of an even bigger asteroid affecting Earth from the dayside. Such a situation is less likely, as the bigger the asteroid the less there are in the Solar System and the easier they are to identify. Undisturbed by Earths atmosphere, its infrared telescope will be able to spot asteroids 20 meters and bigger presently lurking in the sunlight.

This 3D simulation of the Chelyabinsk meteor explosion by Mark Boslough was rendered by Brad Carvey using the CTH code on Sandia National Laboratories Red Sky supercomputer. Andrea Carvey composited the wireframe tail. Credit: Sandia Labs
Nobody saw the Chelyabinsk meteor of February 15, 2013, coming– the largest asteroid to strike Earth in over a century. Simply after daybreak on a bright winter seasons day, a 20-meter, 13 000 tonne asteroid struck the environment over the Ural Mountains in Russia at a speed of more than 40,000 miles per hour (18 km/s).
The relatively small rock exploded in the atmosphere at an elevation of 30 km, launching about half a megaton of energy (equivalent to 35 Hiroshima-sized bombs). 2 minutes later, the shockwave reached the ground damaging countless structures, breaking windows, and hurting approximately 1500 individuals from flying fragments of glass.
Concealed in the glare of our Sun are an unidentified variety of asteroids, on courses we do not understand, a number of which might be heading for Earth, and we just do not understand it.

” Asteroids the size of the Chelyabinsk meteor strike Earth approximately every 50-100 years,” describes Richard Moissl, ESAs Head of Planetary Defence.
Vapor cloud trail left by the Chelyabinsk asteroid as seen by M. Ahmetvaleev on February 15, 2013. It shows the path where an around 20 m-diameter, 13,000-tonne (and formerly unidentified) near-Earth object (NEO) entered Earths environment over the city of Chelyabinsk in Russia. The little asteroid blew up at a height of about 30 km, creating a bright, hot surge with a gas cloud, as well as a large shock wave that broke windows and knocked down parts of buildings and structures. Subsequent media reports said some 1500 individuals were injured by flying glass and other debris, although no deaths were reported. Credit: M. Ahmetvaleev
” Injuries caused by airbursts or comparable occasions could be avoided if individuals are informed of an approaching effect and its anticipated results. With advance warning, local authorities would be able to encourage the public to keep well away from windows and glass.”
Richard includes, “ESAs upcoming NEOMIR objective will spot asteroids like Chelyabinsk coming from the same area in the sky as the Sun, filling an essential gap in our present abilities to anticipate and plan for hazardous effects.”
Of course, there is also the threat of an even bigger asteroid affecting Earth from the dayside. Such a situation is less likely, as the larger the asteroid the fewer there remain in the Solar System and the simpler they are to detect. In truth, almost all asteroids larger than 1 km have already been found.
Asteroid threat described. Credit: ESA, CC BY-SA 3.0 IGO
However as the dinosaurs would inform us, if they could, when a big asteroid strikes it triggers inconceivable damage. Fortunately, as NASAs DART effect has actually revealed and ESAs Hera mission will develop on, asteroid deflection is a real possibility.
So, how do we make sure we are prepared? NEOMIR will be located at the “L1” Lagrange point between Earth and the Sun. Undisturbed by Earths environment, its infrared telescope will be able to identify asteroids 20 meters and bigger currently prowling in the sunshine.
With adequate warning, an asteroid effect is the only natural catastrophe we can prevent.