Two skyscraper-sized asteroids are hurtling toward Earth this weekend, with one approaching on Friday (July 29) and the second on Saturday (July 30).
The first asteroid, named 2016 CZ31, will fly by around 19:00 ET (23:00 GMT) on Friday, whizzing by at an estimated speed of 34,560 mph (55,618 km/h, according to NASA).
Astronomers estimate that the asteroid measures about 400 feet (122 meters) in diameter at its widest point, making it about as wide as a 40-story building. The asteroid will miss our planet safely, passing about 1,740,000 miles (2,800,000 kilometers) from Earth, or more than seven times the average distance between Earth and the Moon.
According to NASA, this space rock makes close approaches to Earth every few years, with the next one scheduled for January 2028.
Related: Why Are Asteroids and Comets So Oddly Shaped?
On Saturday, a second ever-larger asteroid will pass by our planet, albeit at a greater distance from Earth. This asteroid, named 2013 CU83, is about 600 feet (183 m) across at its widest visible point and will pass about 4,320,000 miles (6,960,000 km) from Earth, or about 18 times the average distance between the Earth and the Moon.
This colossal space rock will travel at 13,153 mph (21,168 km/h) when it approaches Earth at 7:37 pm ET (23:37 GMT).
Both close encounters are significantly farther than asteroid 2022 NF, which was 56,000 miles (90,000 km), or about 23 percent of the average distance between the Earth and the Moon, on July 7.
NASA and other space agencies closely monitor thousands of near-Earth objects like these.
Even if an asteroid’s trajectory places it millions of kilometers from our planet, there is an extremely small chance that the asteroid’s orbit could change slightly after interacting with the gravity of a larger object , like a planet; even such a small change could set one
n asteroid in the process of colliding with Earth in a future flyby.
As such, space agencies take planetary defense very seriously. In November 2021, NASA launched an asteroid-redirection spacecraft called the Double Asteroid Redirection Test (DART), which will crash directly into the 525-foot-wide (160 m) asteroid Dimorphos in the fall of 2022.
The collision won’t destroy the asteroid, but it may slightly change the space rock’s orbital path, Live Science previously reported. The mission will help test the feasibility of asteroid deflection, if any future asteroid poses an imminent danger to our planet.
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This article was originally published by Live Science. Read the original article here.