[Reading Science] "Nuclear War Almost Happened Due to Asteroid Explosion 10 Years Ago"

Asteroid Explosion 1m Above English Channel on 13th Sparks Interest
NASA Scientist Reflects on Chelyabinsk Asteroid Explosion
"Asteroid Exploded Above Russian Nuclear Weapon Factory, Lucky It Wasn't Mistaken"

On the 13th (local time), an asteroid (Sar2667) about 1 meter in diameter entered the atmosphere over the English Channel and exploded. It fell like an ordinary "shooting star," creating a tail before suddenly emitting a flash that startled many people. It was detected only six hours before entering Earth's atmosphere. If it had been larger, it could have caused unexpected and tremendous damage. This incident particularly reminded people of the Chelyabinsk asteroid explosion in Russia exactly 10 years ago. It was a "sniper shot" humanity suffered without any prior warning. It became an opportunity to realize the threat of asteroids and to devise global countermeasures. Although not widely known, it was a serious situation that could have nearly triggered a nuclear war between the United States and Russia.

What exactly happened? Dr. Paul Chodas, who has been studying near-Earth objects at NASA's Jet Propulsion Laboratory (JPL), shared his experience with the space news outlet Space.com on the 15th (local time).

Dr. Chodas recalled that he was shocked to hear about the Chelyabinsk asteroid collision without any prior knowledge of its existence. At that time, NASA was busy announcing that another asteroid named "2012 DA14" would approach Earth as close as 27,680 km. It was only through social networks on the day of the event that news of the Chelyabinsk asteroid collision was received. Dr. Chodas said, "It was incredibly confusing. We knew where the (2012 DA14) asteroid was and expected it to pass through the geostationary orbit (GEO) belt," adding, "Suddenly, the Chelyabinsk asteroid appeared from a completely different direction and exploded." In fact, the Chelyabinsk asteroid approached Earth from the direction of the sun, making it impossible to observe with existing astronomical telescopes and other equipment due to the sunlight. While Earthlings were relieved by the harmless asteroid approaching from the front, they were completely unaware of the secretly approaching Chelyabinsk asteroid.

The appearance of asteroid fragments that fell in Chelyabinsk, Russia in 2013 (Photo by AP Yonhap News)

The Chelyabinsk asteroid, about 18 meters in diameter and weighing approximately 7,000 tons, entered the atmosphere at a speed of 64,800 km/h and exploded at 03:20:26 UTC on February 15, 2013, causing tremendous damage. With an explosive force equivalent to about 500 kilotons of TNT, it devastated an area hundreds of miles wide. This is comparable to 25 atomic bombs dropped on Nagasaki during World War II (each about 21 kilotons of TNT). The shockwave damaged most buildings throughout Chelyabinsk, injuring thousands of residents. Many people were hurt by broken glass, and hundreds suffered eye injuries from the flash that temporarily shone brighter than the sun. Even dozens of people reported burns from ultraviolet rays.

The scale was comparable to the 40-meter asteroid explosion observed over the Tunguska River in Russia in 1908, which flattened 21.37 million square kilometers of forest into a plain. It was also the second asteroid explosion observed by modern humanity after Tunguska.

Dr. Chodas recalled that it was fortunate the Chelyabinsk asteroid explosion did not lead to a conflict between the United States and Russia. At that time, Chelyabinsk housed one of Russia's two nuclear weapons manufacturing facilities, the All-Russian Institute of Technical Physics. If Russia had mistaken the asteroid explosion for a U.S. bombing of its nuclear facilities, a nuclear war between the U.S. and Russia could have been triggered. Fortunately, Russian authorities recognized it as a natural phenomenon from the beginning, and nothing serious happened. Dr. Chodas said, "It was lucky that it was not initially mistaken for a military action," and recalled, "I was happy to know that (Russia) accepted it as a natural phenomenon."

In any case, after the Chelyabinsk asteroid explosion, humanity became more alert to the threat of asteroid collisions. International consensus formed around the need to prepare for the possibility that an "invisible extinction agent," like the 10-kilometer asteroid that struck the Yucatan Peninsula in Mexico about 65 million years ago and caused the extinction of the dinosaurs, could reappear on Earth at any time.

A representative example is the Double Asteroid Redirection Test (DART) conducted last year by NASA and the European Space Agency (ESA) on an asteroid near Jupiter. This experiment involved crashing a spacecraft the size of a car into an asteroid to observe whether and how much its orbit changed. The test was successful, proving significant effectiveness, and detailed data will be released within this year. Additionally, NASA has established an asteroid collision warning system through organizations such as the Center for Near-Earth Object Studies (CNEOS) under JPL, providing global alerts. Middle-income countries like South Korea have also formed international asteroid monitoring networks and built their own space object monitoring systems. China plans to conduct an asteroid collision experiment similar to DART soon. At the United Nations (UN) level, the Planetary Defense Conference has been established to regularly discuss global response strategies.