This weekend, two asteroids the size of Skyscraper are speeding toward Earth. One will make its closest approach on Friday, July 29, while the other will pass by on Saturday (July 30). NASA estimates that the first asteroid, 2016 CZ31, will come by at a speed of 34,560 mph (55,618 km/h) on Friday about 7 p.m. ET (23:00 GMT).
The asteroid, which is roughly as wide as a 40-story Skyscraper is tall, is thought to be 400 feet (122 metres) across at its widest point. The asteroid will pass around 1,740,000 miles (2,800,000 kilometres) from Earth, or more than seven times the typical distance between Earth and the moon, safely avoiding our planet. The next near encounter of this space rock with Earth is expected for January 2028, according to NASA.
Thousands of these near-Earth objects are carefully monitored by NASA and other space organisations. There is a very small chance that an asteroid’s orbit could slightly change after coming into contact with the gravity of a larger object, such as a planet; even such a small shift could potentially put an asteroid on a collision course with Earth during a future flyby. This is true even if an asteroid’s trajectory places it millions of miles away from our planet.