'Potentially hazardous' pyramid-size asteroid will make its closest flyby of Earth for more than 100 years this Wednesday

A "potentially hazardous" pyramid-size asteroid is about to zoom past Earth at around 48,000 mph (77,300 km/h) this week as it reaches its closest point to our planet in more than 100 years. But the hefty space rock poses zero risk of hitting us now or in the future, data shows.

On Wednesday (March 26), at around 7:30 a.m. ET, asteroid 2014 TN17 will come within 3.2 million miles (5.1 million kilometers) of Earth — or around 13 times further away than the moon, according to NASA's Jet Propulsion Laboratory (JPL). This is the closest approach predicted for the asteroid across almost 300 years of JPL simulations, which included calculations of all of its flybys between 1906 to 2200.

Researchers estimate that it is around 540 feet (165 meters) wide. That is slightly wider than the height of Egypt's Great Pyramid of Giza and makes it large enough to wipe out a city if it impacted our planet. NASA classifies 2014 TN17 as "potentially hazardous" because of its size and occasional proximity to Earth. However, that does not mean it is dangerous.

Related: NASA's most wanted: The 5 most dangerous asteroids to Earth

During the upcoming flyby, the asteroid will be too far away to be observed with a backyard telescope or stargazing binoculars. However, it is large enough for researchers to study it and the space rock is currently scheduled to be observed by NASA's Goldstone Solar System Radar (GSSR) system in California, which specializes in observing nearby solar system objects as they pass us by.

In recent years, the GSSR telescope has helped reveal the unusual "snowman" shape of one asteroid, detect changes in the orbital trajectories of another and discover a mini-moon orbiting a third. The upcoming observations could yield similarly interesting insights about 2014 TN17.

Close encounters

There are currently around 2,500 known potentially hazardous asteroids, according to the International Astronomical Union's Minor Planet Center. None of them are predicted to hit Earth anytime soon. However, there are a few that will get quite close.

One such space rock is the potential city-killer asteroid 2024 YR4, which made headlines earlier this year when the chances of it hitting our planet in 2032 rose as high as 3.1%. The odds of impact have since dropped to zero. However, there is still a slim chance that it may crash into the moon.

Another asteroid that will have a near-miss of Earth is the hefty "god of chaos" asteroid Apophis, which will come closer to our planet than some satellites in 2029. There is currently zero chance of it hitting us. Some researchers warn that this could change if its trajectory is altered by another asteroid en route — and we may not realize if this has happened for several years. However, this is very unlikely.

In 2022, NASA's Double Asteroid Redirection Test (DART) mission demonstrated our ability to deflect potentially devastating impacts by flying spacecraft into oncoming asteroids to alter their trajectory. However, this method would require advanced warning and lots of data on the target asteroid, which makes finding and tracking these potentially dangerous space rocks a priority.