(NewsNation Now) — A massive asteroid zoomed past our planet late afternoon Tuesday.

The asteroid, known by the catchy moniker (7482) 1994 PC1, passed Earth within 1.2 million miles at 4:50 p.m. ET, according to a NASA tracking website.

It is traveling at nearly 44,000 miles per hour.

“We’ve got to keep an eye on these because it can come back later,” said Dr. David Reitzel, astronomical lecturer at the Griffith Observatory in Los Angeles.

Reitzel says this asteroid has been here before; it was first spotted in 1933.

“Cosmically speaking, 1933 was yesterday,” Reitzel said. “We haven’t known about this a long time. A little nudge here, a little nudge there, it can change paths, and it could come back and hit Earth. So it is very important that we observe these and keep track of them.”

Five other near-earth objects, or NEOs, as the space folks call them, passed by the Earth last week. NASA said three are the size of a house, one the size of a bus and the other the size of a jet airplane. 

None came as close as asteroid (7482) 1994 PC1, which is the size of two Empire State Buildings.

“If one like that comes by and hits the earth, it could be devastating if it hits a metropolitan area,” Reitzel said. “It probably would be fairly devastating even if it hit the middle of nowhere because it would throw so much ash and dust into the atmosphere.”

There are thousands of asteroids and comets zooming through our solar system at this very moment but NASA says none of them pose any serious risk for at least the next 100 years.