Celebrate Asteroid day.
On this day, back in 1908, a large explosion wiped out an area of forest in Siberia about the same size as London. Newspaper clippings from 30 years later attest to the fact that few people were actually affected, but many people saw it
The effect of the collision was also felt in Britain, with a reader writing to the Times newspaper inquiring why the sky was so bright at night. She didn’t receive an answer in 1908, but a 1991 Guardian Notes and Queries offered the hypothesis that the amount of dust thrown up by the blast diffracted the sun’s rays, leading to “someone [playing] a round of golf at St Andrews at 2.30 in the morning.”
So where does a ‘Death by asteroid’ scenario rank on a list of end-of-the-world possibilities. This defintely isn’t the biggest threat to the future existence of mankind (we’re much more likely to destroy each other) but it is a serious concern. There are sizable asteroids on collision courses with Earth and we don’t know about them all. In 2013, this small-ish asteroid hit a much more populated part of Russia.
As reported by the Guardian newspaper in UK,
“The aim of Asteroid Day is to inform the public and raise awareness about the possibility that asteroids can collide with the Earth in the future. Today was chosen to highlight the risk because on the same day in 1908, a 30m object entered the atmosphere over a forested region in Siberia and exploded in mid-air.”
In contrast to other natural disasters, such as earthquakes, an asteroid impact is predictable. Shortly after an asteroid is discovered, its impact probability and time can be calculated to the hour, even if the potential impact is tens of years in the future. In addition, the impact location can be predicted to lie within a so-called “impact corridor”, as shown in the image below. Because of uncertainty in the observations of asteroids, the impact prediction does not produce a point but a corridor that typically stretches across half the globe.
In essence you are unlikely to be in the immediate vicinity of the strike. However, the resulting global effects of a big impact would be Tsunami, fireballs and earthquakes. This would be followed by a dust cloud entering the atmosphere, blocking out sunlight, global climate change and a distinct genetic wipe-out effect. In short, better off to be right at the impact zone – less pain.
So what are we doing, well Space-based telescopes, such as the Sentinel mission proposed by the B612 Foundation, or Nasa’s proposed NeoCam mission, would be able to discover most of the remaining asteroids within 10 years. Such telescopes would also help reduce uncertainty in the observational data. Less uncertainty means that we can make a clearer statement about whether or not an asteroid is likely to strike Earth. Similarly, better observations narrow the impact corridors, and allow us to make better predictions about where a potential impact might occur. So don’t stress too much.