- Are there any near-Earth objects on a collision course with Earth?
- And are there any defence systems to combat them?
We’ll review the risk and defence to intercept a potential collision.
Are we at risk of an asteroid strike?
Simply, no. We’re not at risk at getting hit by a near Earth object. In fact, there are no known significant asteroid risks of impact with Earth over the next 100 years.
We know this because the Jet Propulsion Laboratory tracks all known risks.
The biggest risk of an asteroid impact is less than 0.2% which will be in Earth’s proximity in 2185. If you look over the next one thousand years, there are only a handful of dinosaur-killing scale threats.
How do we know where near Earth objects are?
We mostly use ground-based and space telescopes to find near Earth objects. But there’s some uncertainty if we can spot them all with 100% certainty.
Part of the reason is because ground-based telescopes have limited viewing angles. Because it can’t see in some directions, we miss out on the potential to track some objects in space.
In order to get the whole picture, space telescopes like NEOWISE have more potential for asteroid findings.
What is the most deadly impact ever recorded?
The biggest NEO that struck Earth was the Tunguska impact in 1908. No people died from the impact but it levelled 2000 square kilometers of forests in Siberia.
And the thing is: the impact never actually struck the Earth. Because no remains have been found, it’s believed that the comet or asteroid exploded in the atmosphere.
But if the incoming trajectory took a different path, it would have been devastating for the capital of Russia, St. Petersburg.
As strange as it sounds, after the Tunguska event it took awhile to figure out that there was an impact at all. Almost as if it didn’t happen, until people realized the flattened trees.
What is the DART Mission?
NASA is preparing for one of its largest defense system called the “DART” mission. DART stands for “Double Asteroid Redirection Test”.
The goal of the mission is to intercept any near-Earth object collisions with Earth through a “kinetic impactor technique”.
By colliding into the moon of an asteroid, it’s possible to redirect a crash course into Earth. The test is on an asteroid called Didymos. At the time of collision with Didymos, the impact will be at least 11 million kilometers away from Earth.