While it may not have posed any risk to Earth in its flyby earlier today, the asteroid Apophis has been on a watch list for quite some time now and for good reason.
Aptly named after the Egyptian demon of destruction and darkness, Apophis, as was once calculated by scientists, could likely collide with Earth in a couple of decades. However, it gave our home planet a wide berth as it passed by at a distance of 14 million kilometres.
First spotted in 2004, the 300-meter wide Aphosis first drew alarm as scientists calculated that the asteroid had a one in 45 chance that it would strike Earth in 2024, and what’s more, that it could do so with a force 100 times the energy in any of our largest nuclear bombs. However, this was later revised to the ominous date of Friday, April 13, 2029, when it would pass by Earth at a distance of some 300,000 kilometres. Of course, owing to the proximity with which it would fly by, Earth’s gravity would likely have an effect, changing its orbit, and while this altered orbit, according to scientists, would keep us safe for the next century or so, there is a chance, a one in 200,000, that on April 13, 2036, the asteroid could strike Earth.
Speaking about this, Professor Alan Fitzsimmons, of the Queen's University Belfast, Ireland, said, "In 2029, it will pass so close to us that Earth's gravity will change its orbit. Most of the potential orbits it will end up on will mean we are safe for the next 100 years. But there is a small region of space - something we call a keyhole - and if it passes through that keyhole in 2029, it will come back and hit us on 13 April in 2036."
With its present fly-by and distance, scientists will be given the chance to study the asteroid and of course assess its potential danger to possibly try and improve on the present calculations. According to present estimates, there are presently some 9,000 near-Earth asteroids out there, with 800 discovered on an average every year. Of course, studying and tracking them is essential. Prof. Fitzsimmons added, "At some point, we are going to find an asteroid big enough that it could cause damage at ground level if we let it hit. So we should find these objects, we should track them, work out where they are going - and if they stand a chance of hitting us, do something about it."