A giant asteroid thought to be so large that it could fit in the Great Pyramid of Giza nearly three times over is headed toward Earth for a so-called "close approach" later tonight, NASA has announced. The massive rock is shrieking across space at an incredible speed of just under 53,000 mph and will safely pass by our planet at 11:52 p.m. EDT. NASA assures the flyby is nothing to worry about, as the asteroid will miss Earth by 4.1 million miles. To put that into perspective, that's 17.33 times the distance to the moon.
Tonight's celestial visitor is known as asteroid 2012 XA133 and has been in the NASA records for a long time. As its name suggests, the object was discovered seven years ago -- on December 11, 2012, to be exact -- precisely one month after it buzzed Earth from 24.1 million miles away. According to NASA's Center for Near-Earth Object Studies (CNEOS), the space rock is estimated to measure anywhere between 590 feet and 1,280 feet in diameter. At the upper end of that size estimate, the asteroid is taller than the Empire State Building and 2.8 times the size of the iconic Egyptian pyramid.
Even at the lower end of NASA's size estimate, the rock is large enough to pose a serious concern, should it venture too close for comfort. A 590-foot asteroid is almost twice as big as the Statue of Liberty and 1.3 times larger than the Great Pyramid of Giza.
Due to its impressive proportions, the rock has been flagged as a "potentially hazardous asteroid," or PHA. To clarify, this doesn't mean that it is a threat to our planet or stands a chance of slamming into Earth. The PHA designation has to do with the object's towering size and proximity to our planet, as is given to all asteroids that are at least 460 feet wide and pass within 4.66 million miles of Earth's orbit.
Ever since its discovery, NASA has kept close tabs on the huge asteroid, carefully calculating the rock's orbit to determine how close it will come to Earth. Orbital data gathered by the agency's Jet Propulsion Laboratory (JPL) showed that the object circles the sun once every 1.53 years, frequently passing by Earth, Venus, and Mercury as it orbits the giant star. Its recurrent trek through the inner solar system has brought it to our neck of the cosmic woods 28 times over the past 118 years. Based on its orbital path, the rock falls into the category of Apollo asteroids, which means it has the potential to occasionally cross Earth's orbit.Interestingly enough, tonight's close encounter with Earth will be the closest that asteroid 2012 XA133 has gotten to our planet in 31 years. The object previously visited Earth in 2018, when it passed some 44.3 million miles from the planet's surface. Its closest-ever approach occurred in 1989 and brought it within 1.5 million miles from our planet.
The asteroid is expected to return in 2023 -- when NASA predicts it will fly 34.6 million miles from Earth -- and then again in 2035 and 2038.