Space groups like NASA and the ESA track on a daily basis and many of them have a chance to make a miserable life. These are "most likely to be true" on September 9th, 2019.
That's when the rock known as 2006 QV89, at asteroid measuring just over 160 feet wide, is set to make its closest approach to Earth in some time. The ESA says there's a very tiny chance it could end up here on earth.
ESA's risk-tracking database relies on models and calculations based on past observations, and those measurements are typically very accurate. However, there's always a small chance that they're not spot-on, and even more likely that they're off.
For asteroid 2006 QV89, the chance of impact is slim, but present. According to the ESA, the asteroid has a 7,300 chance of slamming right into our planet. At 164 feet wide, the asteroid is not exactly a "planet-killer," and even if it struck Earth it would not be the end of the world. Yes, if it struck land, especially in a highly populated area, it could be some very serious damage. If it hit offshore, it could even cause a tsunami to form.
The good news here is that it does not take much time to get it done.