What is a potentially hazardous asteroid? 'Twice the size of Empire State Building' asteroid to pass Earth on January 18

The 1994 PC1 (Image via Eyes on Asteroids/NASA)
The 1994 PC1 (Image via Eyes on Asteroids/NASA)

As per NASA's Center for Near-Earth Object Studies (CNEOS) estimates, a "potentially hazardous" asteroid (aka a minor planet) is set to pass by Earth on Tuesday, January 18.

It is named (7482) 1994 PC1 and was discovered in 1994. The PC1 minor planet was recorded to be around 1.05 km in diameter, comparable to three-and-a-half vertically stacked Eiffel Towers.

The 1994 PC1 will reportedly pass Earth at a distance of 0.013 astronomical units (roughly 1,981,464 km). More importantly, it will be at its closest on Tuesday. In 1933, around the same time, it strayed even closer to the planet at around 1.1 million KMs.


According to Space Reference, the 1994 PC1 is around the size of the Golden Gate Bridge in diameter, which makes it around 99% larger than other comparable ones.

The Apollo-class asteroid is classified as a Potentially Hazardous Asteroid (PHA). Coincidentally, it is also just shy of being three times the size of the Empire State Building.

"Potentially Hazardous" asteroid - What it means, and why 1994 PC1 is categorized as one

1994 PC1's orbital path on January 18 (Image via Jet Propulsion Laboratory/NASA)
1994 PC1's orbital path on January 18 (Image via Jet Propulsion Laboratory/NASA)

Nasa's Jet Propulsion Lab (JPL) categorized the 1994 PC1 as a "Potentially Hazardous" mid-sized asteroid, owing to its eight close-call approaches in two centuries. However, unlike the events of Netflix's new disaster-comedy, Don't Look Up, 1994 PC1 is unlikely to collide with Earth.

"Potentially Hazardous" objects are defined as large astronomical bodies which pass the Earth's orbit at a distance closer than 0.05 astronomical units (or 7,479,894 KMs). These objects pose catastrophic threats if they collide with the planet. However, most of these are not predicted to hit Earth for the next few centuries.

1994 PC1 does not pose much threat as it is passing by Earth at a distance that is over five times the space between the planet and the moon. After passing the Earth at a velocity of 19.555 KMs per second, it will have its next closest approach on January 18, 2105. The minor planet completes its revolution around the Sun every 572 days, which is just shy of one year and seven months.

How to watch the 1994 PC1?


As per the report, the 1994 PC1 can be spotted at 4:50 PM EST (or around 9:50 PM GMT). However, it might be challenging to spot with the naked eye depending on location and weather.

Astronomy enthusiasts might have better luck observing the (7482) 1994 PC1 with a telescope sporting a six-inch or larger aperture size. It will have a peak visible magnitude of 10.

Edited by Sijo Samuel Paul
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