NASA alerts about building-sized asteroid's close approach
Technology
Heads up: On June 12, asteroid 2015 XR1—about the size of a 21-story building—will zoom past Earth at a wild speed of over 45,000km/h. No need to worry, though; it'll stay a safe 6.9 million kilometers away (that's over 18 times the distance to the Moon).
A member of the Apollo group of asteroids
2015 XR1 is part of the Apollo group, which includes asteroids that cross Earth's orbit and are closely watched by scientists. There are 21,083 of these Apollo-class asteroids out there, so keeping tabs on them is key for our planet's safety.
Why tracking near-Earth objects is important
Even though most near-Earth objects pass by harmlessly, their orbits can change over time. That's why NASA and other agencies keep a constant eye out—to spot any potential threats early and help protect Earth in the long run.