In two days, Earth is going to have a close call with a huge asteroid, one that, if it were to hit, could easily threaten human civilization as we know it. Fortunately, the asteroid, named 4179 Toutatis, is going to miss our planet, but will still come close enough to pass within 4 million miles. On the scale of the cosmos, that is a very close shave.
For people who are even slightly familiar with the solar system, it is common knowledge that Earth is in the middle of a cosmic shooting gallery with millions upon millions of asteroids constantly hurtling through the solar system at almost unimaginable speeds. Fortunately, though, Toutatis will pass Earth with plenty of distance to spare, thus posing no threat to our world.
As for asteroids themselves, most lie in the Main Asteroid Belt, which lies between Mars and Jupiter. In the Early solar system, dust was everywhere. In time, dust particles started colliding and clumping together. As the groups of gravitationally-bound space debris got bigger and bigger, they attracted most of the loose space debris in the solar system to form the planets. However, for reasons unknown, the asteroids between Mars and Jupiter never coalesced into a planet, thus resulting in the Asteroid Belt. Occasionally, asteroids collide, sending both out of the belt and flying on random trajectories through space, which is almost certainly what happened with Toutatis, which will make its close pass in about 2 days.
Toutatis is nearly 3 miles long, thus making it one of the largest potentially hazardous asteroids (PHAs). The really good news: according to NASA’s Near Earth Object Program, Toutatis poses no impact hazard for hundreds of years.
Still, the asteroid will be coming close enough to warrant intense study from scientists, who plan to use both radar and optical imaging to try and get a close look at the space rock. Expect follow-ups in the coming days.