NASA has spotted an asteroid that’s currently heading for Earth. According to the agency’s Center for Near Earth Object Studies (CNEOS), the approaching asteroid is almost as big as the Chicago Water Tower.

The approaching asteroid is called 2019 NN4. It was categorized by CNEOS as an Amor asteroid due to its orbital path around the Earth and the Sun. Unlike other asteroids, 2019 NN4’s orbit does not intersect with that of Earth’s. Instead, it only flies near the planet during certain periods.

Due to its close approaches, CNEOS has dubbed 2019 NN4 as a near-Earth object (NEO). According to the space agency, NEOs are space rocks that were affected by the gravitational forces of nearby cosmic objects.

“Near-Earth Objects are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter Earth’s neighborhood,” CNEOS stated.

“Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter,” the agency added.

CNEOS estimated that 2019 NN4 will fly past the planet on July 29 at 1:22 a.m. ST. During its approach, the asteroid will be about 0.01698 astronomical units or around 1.6 million miles from the planet’s center.

According to the data gathered by the agency, the asteroid is currently traveling at a speed of 8,400 miles per hour and is estimated to be about 141 feet long.

2019 NN4 was first observed on May 8. CNEOS noted that the asteroid’s first recorded Earth approach occurred on Aug. 5, 1907.

The last time 2019 NN4 visited Earth’s neighborhood was on Aug. 26, 2011. During this time, the asteroid flew past Earth from a distance of 0.11172 astronomical units or around 10.3 million miles away.

After its upcoming approach, CNEOS predicted that the asteroid will return to Earth’s vicinity on June 20, 2027. The agency estimated that the asteroid will be about 0.08454 astronomical units or roughly 7.9 million miles from the Earth’s center during its future flyby.