Potentially Hazardous Asteroid as Big as the Empire State Building Will Fly Uncomfortably Close to Earth. Today.

Don't look up.

At approximately 6:55 p.m. EST today (Thursday), Asteroid 2013 BO76 will give Earth a too-close-for-comfort driveby. The chunk of rock, estimated to be roughly the size of the Empire State Building, will zip by our home planet at speeds close to 30,000 mph.

A direct hit would be catastrophic, but happily, the term "close" is all relative when discussing the expanses of space. 2013 BO76 will come within 3.1 million miles of our home, which is more than 13 times farther away than the moon, reports Newsweek. That might not sound super close, but it is enough to earn the PHA (Potentially Hazardous Asteroid) tag.

Related: Inside SpaceX: What It's Like Working for a Company on a Mission

What is a potentially hazardous asteroid?

The Center for Near Earth Object Studies defines a PHA as one that comes within around 4.6 million miles or closer to Earth and has a diameter of 140 meters or greater. Are there many out there? Short answer: Yes. The Jet Pulpusion Laboratory searches for and tracks near-Earth asteroids of all sizes, and, at last count, has 28,541 on its radar.

The Science Times explains that the next close call we can expect is from Asteroid 2005 ED224, which will be making an appearance in March 2023, zipping by at 61,000 miles per hour. This 164-foot asteroid is said to have a 1 in 400,000 chance of hitting Earth, according to CNEOS. (We'd prefer an extra zero or two tagged onto the end of those odds, to be honest.)

Related: NASA Launches Mission to Stop Killer Asteroid From Destroying Earth

What would happen if Earth gets hit by a huge asteroid?

Marshall Brain and Sarah Gleim, writing for How Stuff Works: Science, break down the effects by size:

• An asteroid the size of a house would be equivalent to the bomb that dropped on Hiroshima, creating extensive damage to any city it hit.
• An asteroid the size of a 20-story building would hit with the equivalent power of a modern nuclear weapon, completely flattening any city it hit.
• An asteroid seven-to-eight-miles wide would kill almost everything and everyone on Earth. Beyond its immediate impact, it would send up a sun-blocking dust plume that would encapsulate our planet.
• An asteroid 60 miles wide would be an Earth killer, instantly zapping any and all life forms.

Happy Thursday!