One of the asteroids will make its closest approach to Earth on Friday and the other on Saturday.

According to NASA, the asteroid will fly by at an estimated 34,560 mph on Friday.

It is estimated that the asteroid is about as wide as a 40 story building. More than seven times the average distance between Earth and the moon will be missed by the asteroid.

The next space rock to make a close approach to Earth will be in January of 2028.

There are asteroids and comets that are strange.

A bigger asteroid will skim past our planet on Saturday at a greater distance from Earth. About 18 times the average distance between Earth and the Moon will be reached by the asteroid named 2013CU83, which is about 600 feet across.

The space rock will travel at an average speed of 21,168 km/h when it is near Earth.

The distance between Earth and the Moon is about 23 percent of the average distance, but the close encounters are much farther away.

Thousands of objects like these are closely monitored by NASA and other agencies.

Even if an asteroid's trajectory puts it millions of miles from our planet, there is an extremely slim chance that the asteroid's path could change slightly because of the gravity of a bigger object.

On a future flyby, an asteroid will collide with Earth.

Space agencies are very serious about planetary defense. The Double Asteroid Redirection Test will slam into the asteroid Dimorphos in the fall of 2022.

The collision won't destroy the asteroid, but it may change the space rock's path. Should a future asteroid pose an imminent danger to our planet, the mission will test the viability of asteroid defense.

There are related content.

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What happened when the asteroid hit?

There are impact craters on Earth.

The original article was published by Live Science. The original article can be found here.