One of the Biggest Asteroids of 2022 Will Make Its Close Approach to Earth in January

An asteroid, classed as potentially hazardous by astronomers, is due to make one of its closest known passes to our planet next month. The space rock, called 7482 (1994 PC1), will not hit Earth and will shoot past our planet. It won't come so close again for decades.

1994 PC1 is expected to pass Earth at a distance of 0.013 astronomical units on January 18. Although this is technically a "close approach" according to NASA's Center for Near Earth Object Studies (CNEOS), this distance translates to around 1.2 million miles—more than five times as far away from us as the moon is. Many asteroids also make close approaches to Earth every year.

Part of the reason 1994 PC1 is classed as a potentially hazardous asteroid (PHA) is because of its size. According to CNEOS, the space rock is estimated to be around 1 kilometer or 3,280 feet in diameter—give or take 1,000 feet—or around 2.5 times the height of the Empire State Building.

When it makes its pass by Earth in a few weeks' time, 1994 PC1 is due to be travelling at a speed of around 43,000 miles per hour. Afterwards it will shoot back off into the solar system to orbit the sun once again, which it does once every 1.5 years or so. However, it won't come this close to Earth again for decades—the year 2105, according to NASA.

1994 PC1 was discovered in the year 1994 by R.H. McNaught at the Siding Spring observatory in Australia, according to The International Astronomical Union's Minor Planet Center.

When astronomers classify an asteroid as potentially hazardous like 1994 PC1, it does not necessarily mean that it will ever hit Earth. A PHA is defined based on a number of characteristics, including how close it's expected to come to Earth and what its estimated size is.

Specifically, any asteroid that can't get any closer to Earth than around 4.6 million miles or is smaller than around 500 feet in diameter is not considered to be a PHA, CNEOS states.

Systems are in place to continually track thousands of known asteroids in case one of them poses a threat to Earth. Currently CNEOS lists around 28,000 known near-Earth asteroids, with roughly 1,000 of these being a kilometer (3,280 feet) in size or more.

At the time of writing, none of them are expected to collide with the Earth any time soon.

However, scientists are still preparing for such an event. In November this year, NASA launched the Double Asteroid Redirection Test (DART) mission that marks the world's first mission to test technology that is hopefully capable of defending Earth from an incoming space rock.

The purpose of the DART mission spacecraft is to slam into the side of a small space rock called Dimorphos next year at a speed of around four miles per second. Scientists will then measure how much difference this impact makes to its path through space.

Asteroid
A stock photo shows an asteroid in space against a backdrop of stars. Scientists track thousands of space rocks to make sure none are due to hit Earth. IngaNielsen/Getty