The Largest Asteroid To Hit Earth

Written by Colby Maxwell
Updated: September 3, 2023
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If there is one thing that makes a good movie, it’s the potential for an asteroid to hit the Earth! Although the concept is a scary one to imagine, there are, thankfully, no asteroids that are currently on track to hit the Earth. Still, that doesn’t mean that Earth hasn’t been hit in the past! Today, we are going to be exploring just that: the largest asteroid to ever hit the earth. It probably isn’t the one you are thinking of! Let’s get started and find out.

For a long time, scientists underestimated Vredefort’s size, mostly because of the crater measurements they were taking.

The Largest Asteroid to Ever Hit Earth

The largest asteroid to ever hit Earth was an asteroid named Vredefort. This absolutely gargantuan asteroid was likely around 12.4 to 15.5 miles across and was traveling between 45,000 and 56,000 mph when it hit the surface. For reference, Manhattan is roughly 13.4 miles long, right down the middle of the current estimates for Vredefort.

For a long time, scientists underestimated Vredefort’s size, mostly because of the crater measurements they were taking. Until recently, it was understood that the Vredefort asteroid was probably around 9.3 miles long when it hit, but the newest measurements essentially doubled it. The issue was that scientists were using the crater’s measurements in order to guess the size of the asteroid, but they didn’t account for as much erosion of the crater as they should have. Currently, the crater measures 107 miles wide, but since the asteroid hit over 2 billion years ago, the crater has slowly filled in and changed shape. With a new and more accurate erosion estimate, the original size of the crater was expanded, and the size of the Vredefort asteroid was subsequently updated.

Vredefort Crater

The Vredefort Crater in South


was created by the largest asteroid to ever hit the earth.

©Júlio Reis (User:Tintazul) / public domain

Did the Vredefort Asteroid Cause a Mass Extinction?

Part of the reason that measuring the Vredefort asteroid was tough wasn’t just that the impact site had eroded quite a bit over 2 billion years. There was also no way to see the larger-scale impact it had on the ecology.

When the asteroid hit, life on Earth was extremely primitive, with only single-cell lifeforms really starting to make headway across the planet. There were no dinosaurs, trees, or anything else that might have given some fossil indication that there was a huge extinction event that was felt across the planet from the impact. On the flip side, the famous Chicxulub asteroid that hit the earth and wiped out the dinosaurs was clearly seen in the fossil record, giving a bit of context to how far the shockwave and impact spread.

Despite being potentially the largest energy-release event in Earth’s history, besides the crater, there is little sign that the Vredefort asteroid even hit. Still, the global climate was impacted, probably even more so than the dinosaur’s asteroid. There just wasn’t anyone around to feel it!

The Second (and Most Famous) Asteroid to Ever Hit Earth

The second largest asteroid to ever hit Earth was the Chicxulub asteroid, estimated to be about 10 to 15 kilometers in diameter. It impacted the Yucatán Peninsula in Mexico approximately 65 million years ago. The impact released energy equivalent to several million atomic bombs and is likely what caused the mass extinction of the dinosaurs, making it one of the most famous events in the history of the earth.

To give perspective to its size, this asteroid was about 4-6 times the size of Mount Everest and about 1,000 times the size of the Great Pyramid of Giza. A blast from an asteroid of this size would have caused widespread devastation and would have been felt globally. The impact caused a massive crater over 100 miles wide and created tsunamis, earthquakes, and intense heat, leading to the extinction of 75% of all species on Earth, including the dinosaurs.

Unlike the Vredefort asteroid, there were plenty of multi-cellular creatures around during this blast and the impact (literally and figuratively) can be seen quite clearly. Across the fossil record, it’s estimated that around 75% of ALL life on earth was wiped out, ending the age of the dinosaurs and making way for the age of mammals.

asteroid that ended dinosaurs

The Chicxulub asteroid impacted Yucatan, Mexico which ended the age of the dinosaurs.


Could Earth Get Hit By Another Asteroid?

Although it’s possible that the Earth could be hit by an asteroid, it isn’t likely in the near future. Scientists and astronomers are constantly on the lookout for any large astral body that could potentially intersect with Earth. With that many eyes out there looking, it would be hard for anything large to sneak past. If there was something large heading toward Earth, we would also see it well before it was close enough to strike.

Even further, humans are currently working on ways to deter potential asteroid strikes if they were to be seen as a possibility in the future. Currently, the best plans involve sending Bruce Willis into space to drill a hole in the asteroid, but if that doesn’t work, the next best ideas involve sending kinetic deflectors and knocking the asteroid off course. In these situations, early detection is key for the best results.

The photo featured at the top of this post is © Marti Bug Catcher/

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About the Author

Colby is a writer at A-Z Animals primarily covering outdoors, unique animal stories, and science news. Colby has been writing about science news and animals for five years and holds a bachelor's degree from SEU. A resident of NYC, you can find him camping, exploring, and telling everyone about what birds he saw at his local birdfeeder.

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