The sky is beautiful but it is also full of danger, like the many asteroids that often come close to our planet. One of these, 2016 QA2, got as close as 80,000 kilometers (50,000 miles) to Earth last Sunday, and the scary part is that it was only discovered a day earlier.

The object orbits around the Sun in 350 days, and it has an estimated size between 25 and 65 meters (80 and 180 feet). That might seem small, but such an object would have a mass of tens of thousand tons, like a large cruise ship, and it’s moving at about 7.8 kilometers per second (17,400 miles per hour) according to the IAU Minor Planet Center. It might not create a planet-wide cataclysm, but such an object remains clearly dangerous.

There are about one million hazardous asteroids larger than 30 meters (100 feet) in size around Earth, but we have found only about 1.5 percent of them so far. ESA and NASA both have projects working on monitoring near-Earth objects (NEOs) but there’s still a lot to do. Only about one-quarter of the hazardous asteroids larger than 100 meters (330 feet) have been found, but they don’t have to be that big to pose a threat to a town or city.

For example, the Chelyabinsk meteor in 2013 that exploded in the atmosphere was smaller than 2016 QA2, being about 20 meters (65 feet) across, yet it created a shock wave powerful enough to shatter windows and injure almost 1,500 people.

We don’t have to be that alarmed regarding NEOs, but at the same time, we can’t pretend there’s no risk. Understanding and studying the peril will hopefully give us what we need to prepare in the event we do find something with our name on it.

[H/T: Space.com]