680-Meter-Wide Asteroid Is Approaching Earth Today

A massive asteroid estimated to be larger than the Empire State Building is heading toward Earth and is set to zoom past the planet this week.

NASA'S Center for Near-Earth Object Studies (CNEOS) is keeping a close eye on an asteroid called 1999 RM45, which will pass by Earth on Tuesday at approximately 3:52 p.m. EST.

First observed in September 1999, this 2,230-foot (680 meters) asteroid is currently traveling at a speed of 45,000 miles per hour (72,000 kilometers per hour), according to the CNEOS' Close Approach database.

During its upcoming flyby, asteroid 1999 RM45 could get as close as 1.8 million miles (0.01959 astronomical units) from the Earth's surface.

With its considerable diameter, the space rock is larger than the Petronas Twin Towers -- the twin skyscrapers in Kuala Lumpur, Malaysia that stand at a height of 1,482 feet (452 meters). Asteroid 1999 RM45 is also bigger than the 381-foot Empire State Building in New York, per The Measure of Things.

Despite its size and proximity to the planet during its upcoming approach, the European Space Agency has assured that the asteroid's flyby shouldn't be a cause for concern. It has not been included in the space agency's Risk List and does not fall under its Priority List.

This is good news as an asteroid of this size would do considerable damage if it manages to collide with Earth. According to NASA, any space rock "larger than 25 meters but smaller than 1 kilometer (a little more than 1/2 mile)" is expected to "cause local damage to the impact area" if it enters Earth's atmosphere and hits the ground.

An asteroid is a small, rocky object that orbits the sun, similar to a planet. The difference between the two, however, is their size. According to NASA Science's Space Place, asteroids are much smaller than any of the planets in the solar system. Although most of them remain in the asteroid belt, some asteroids can be found in the orbital path of other planets such as Earth.

Asteroids such as 1999 RM45 are often regarded as possible gateways to the past as most of them formed at the same time as other objects in the solar system -- becoming carriers of the universe's history.

In 2016, NASA launched OSIRIS-REx -- a spacecraft that set out to study the asteroid Bennu. Equipped with modern-day engineering, OSIRIS-REx was able to collect samples from the asteroid that would enable scientists to learn more about the universe and its possible origins.