It may not be today or tomorrow, but it could be... Let's learn about asteroids out there that we should be worried about.
We've all seen doomsday movies about massive, deadly asteroids making a beeline for Earth. Fortunately, a few brave souls figure out a plan to save the day and humanity survives.
Well, the bad news is that this scenario is unlikely should we find a potentially deadly asteroid heading our way. According to Professor Dave Jewitt from UCLA Astronomy, an asteroid of around 10km wide took out the dinosaurs. Bad, right? But they were large reptiles without the technology to blast it out of the sky.
Well, as it turns out, that doesn't matter because there's nothing humanity can do about an asteroid that size. In fact, an asteroid of just one kilometre wide would be deadly. It would have the potential to obliterate an entire country the size of France or Germany.
You see, he was a part of a brain trust about a decade ago that got together to discuss this very topic. Based on a 1km wide asteroid, they discovered that blowing it up with a nuclear warhead won't help. This is because gravity will simply pull all the debris back together – and all of it will hit the Earth anyway.
Other solutions were to wrap it in tinfoil to change its radiative properties, pushing it off course. Unfortunately, how would we get enough cooking foil into space, and how would we go about wrapping an entire asteroid with it?
Other ideas included trying to push it with a spacecraft or blasting it with lasers. Neither of which do we possess that is big enough to make a dent.
There is some good news, though. According to the professor, there is no super-large, 10km wide asteroid heading for us. It is believed too that we know of about 98% of the one to two kilometre wide asteroids that could potentially wipe out a large chunk of Europe. They've been mapped and, happily, we're safe for a few years.
What about the missing two per cent, though? And those that are less than a kilometre but still significantly large? Well, those are the ones that pose a problem because there are plenty of them.
An asteroid with a 100m diameter, if it struck the Earth, it would throw up ejecta that would come back down at a tremendous speed, effectively destroying everything in a 100km zone. Say goodbye to Barcelona, which is almost twice the size of Manhattan.
The guys over at Vertasium on YouTube have put together an informative and, frankly, frightening video for us to peruse. It's insightful and includes an excellent interview with professor Jewitt, who happens to own a piece of iron core from a small planet from the early days of our solar system.
To learn more, then smash that play button below, If Stephen Hawking thought an asteroid impact was the greatest threat to life on Earth, then maybe we should pay attention.