TC4 came so close to Earth this time around that it was nearly within the orbit of many of our satellites, and just a fraction of the distance between Earth and the Moon. Based on current models forecasting its path, the rock will perform another near-miss in 2050, and we should be safe for that event, but its return in 2079 is giving scientists a reason to worry.

Source: Asteroid that barely missed Earth this week could wreak havoc in the not-so-distant future – BGR