Although it wasn’t the end of the world, those who saw a fiery asteroids fly towards Chelyabinsk in the Russian city will never forget what it did.
It was about the same size as a house, and traveled at an incredible 11 miles per hour. The Chelyabinsk Meteor arrived unexpectedly in a way that reminded of a science-fiction disaster movie. It was a frightening sight.
Dashcam footage taken in the morning of February 15, 2013, in the central Russian town near the Ural Mountains shows the tiny asteroid entering Earth’s atmosphere. It exploded with 30 times the force of the US atom bomb that decimated Hiroshima during the Second World War.
Windows were smashed, buildings were destroyed, and hundreds were hurt – but Chelyabinsk was lucky.
“Had it been over the city, then the damage would be worse,” warns Lindley Johnson, NASA‘s planetary defense officer. It was certainly a wake up call.
“We’ve never seen anything similar since”
Johnson’s Department, in collaboration with European Space Agency partners, warns Earth about any comets or asteroids impacting Earth and directs the response.
One standard test case was an “shooting star” asteroids that flew above the English Channel this Week. This was publicised in advance so that people could see it.
Chelyabinsk wasn’t a standard case.
Johnson says that “we’ve never seen anything similar since we began working in this region,” and his office within the US space agency was established only in 2016.
It was clearly visible in the sky at daytime, which isn’t something that happens very often.
“It arrived on the daylight side, and we didn’t have any chance of being able detect it before time with ground-based observatories we used at the time to find these objects.”
What is the chance of another Chelyabinsk.
On the day of Chelyabinsk arrived, Johnson was in Vienna (Austria) to attend meetings of UN members of the Committee on the Peaceful Uses of Outer Space.
It wasn’t long before recommendations were made on how to protect Earth from such disasters, including an international warning network.
Professor Alan Fitzsimmons of Queen’s University in Belfast is an expert on these so-called near Earth objects and a dedicated member of the “planetary defense community”.
He says, “We are very transparent about what we find” and the current state of our knowledge about potential impacts risks. “All detected asteroids are made public on the Internet.
Although technology has made it easier to detect asteroids (even those as small as Chelyabinsk), there is still the possibility that one might slip through. It’s very likely that we won’t be able to predict the next important asteroid.
How can we protect ourselves?
Chelyabinsk had been considered a small asteroid. Its arrival at daylight was why it was so hard to see.
Johnson admits that “we’re still susceptible to those who are coming from the sun,”
“Most of these objects are from the main belt of asteroids between Mars and Jupiter. We can locate them in the nightsky when they are coming inbound to the inner solar system. However, when they circle the sun and return out, we are vulnerable.
Space-based observation is the key to anticipating the unexpected.
NASA is currently working on the Near-Earth Object Surveyor (NEO) Surveyor, costing $1.2bn (PS985m), which will launch in 2028. It will be the first space telescope designed specifically to hunt comets and asteroids that could pose a threat to Earth.
Even so, Chelyabinsk was smaller than the asteroids NEO Surveyor will be focusing on. Amy Mainzer is NEO Surveyor’s principal investigator and she says that it will prioritize “finding one asteroid which could cause a really terrible day for a lot people”.
The Double Asteroid Redirection Test spacecraft (Dart), is also included in the list. It was intentionally crashed into an asteroid during testing last year and successfully altered its orbit.
What happens if another one is successful?
Chelyabinsk’s arrival demonstrated the importance of fast and effective communication. Its arrival was quickly documented around the globe by Russian scientists, who shared their findings with others. Fragments were collected, studied and given new homes. The event also informed international policy.
Professor Fitzsimmons believes that transparency and coordination are vital again, especially in an age when misinformation can spread quickly.
If such an asteroid were to strike the atmosphere today, in an area populated, it would do so in a much more fragile geopolitical environment than in 2013. With Russia’s war in Ukraine, and an increasing US-China row about the perceived threat from flying objects.
Johnson says that when these types of events are found to have natural causes, information flows pretty well even in today’s world. It is important to know quickly if it is a natural or human-caused event.
“The heat pressure in the atmosphere can cause these objects to explode, which, to the naked eye, could look like an attack. However, sophisticated instrumentation quickly distinguishes the difference.”
“A long way to go before they all appear”
There are currently 31,000 asteroids being surveyed – an increase of around 9,500 since 2013.
This is a sign that the danger of an asteroid impact has been taken more seriously since Chelyabinsk in 1908. It was the most significant and well-recorded asteroid impact since 1908. This was the moment an asteroid burst over Siberia and flattened some 80 million trees with a blast equal to 15 million tonnes of dynamite.
It was again extremely fortunate not to be in a densely populated area.
Russia’s size alone has made it an asteroid hotbed. 70% of Earth is covered by water so it’s likely that most asteroids, detected or not, end up in the ocean. NASA believes that an impact such as Chelyabinsk will only happen once in a century.
Prof Fitzsimmons says that none of the 31,000 known asteroids are expected to reach Earth within the next 100 years. However, he believes there is still “a lot to do” to find them all.
“But, I can assure you that I still go to work and contribute to my pension plan.
