According to a new study conducted by Chinese astronomers, there could be as many as a million small asteroids heading towards our planet within the next century. But apparently there’s no need to panic as the impact risk is low and the majority of the asteroids are less than 100 meters in width (328 feet). On the other hand, they if they do impact our planet, they would have more kinetic energy than what is in an atomic bomb.
The current number of known asteroids is 1,113,527 – some measuring as large as hundreds of miles in diameter while the smaller ones are less than 33 feet (10 meters) in width. Most of the known asteroids are located in the asteroid belt between Mars and Jupiter. In fact, there are an estimated 1.1 to 1.9 million asteroids located there that are bigger than 1 kilometer in diameter (0.6 miles) with millions of smaller space objects.
Professor Gan Qingbo and colleagues at the Space Debris Observation and Data Application Centre at the China National Space Administration stated that the short-term hazardous asteroids (SHA) are very hard to track in space as they explained, “The accurate identification of impact threat targets and early warning capabilities requires more precise algorithms for orbit determination and impact risk assessment.”
The researchers looked through a global asteroid database and focused on the orbits of smaller asteroids and they discovered that over 700 of them could potentially hit our planet in the next century. Five of the asteroids had a one in a thousand chance of impacting our planet, although their constantly changing orbits could affect those probabilities. Then they conducted physical models on asteroid formation and estimated that there could be between 100,000 and a million short-term hazardous asteroids lurking around.
Since a lot of astronomers focus their attention on much larger space objects, they could be ignoring the smaller asteroids that may also be potentially dangerous. For example, a small asteroid measuring just 19 meters (62 feet) exploded over Chelyabinsk, Russia, in 2013 but it still caused an extremely powerful explosion that was approximately 30 times stronger than the Hiroshima blast. Furthermore, the shock waves caused damage to over 7,200 buildings but thankfully nobody died.
This is a perfect example of a small asteroid causing significant damage. There is no reason for us to run for cover though as Professor Chen Ping, who is a Guangzhou-based geologist with the Chinese Academy of Sciences, explained that the SHAs are “an interesting topic for academic research and public discussions, but that should be as far as it goes,” and that since they are so small, they would probably just burn up in our atmosphere. Let’s hope he’s right.