Ah, yes, asteroids. Whenever we hear the word, we automatically think of the final days of the dinosaurs or perhaps the apocalyptic films that started with the concept of a mega asteroid impacting our home planet.
Even when we look back at the doomsday prophecies (whether they have passed or are currently being spread), most would include a menacing asteroid more giant than Earth, wiping out life forms once it hits.
While no one knows how our end will be or when it will be, one thing is a fact: there are indeed ginormous asteroids out there threatening the planet. Astronomers have already found over 90% of these destructive asteroids, but fortunately, they have only whizzed close to Earth.
Astronomers have used specialized telescopes to discover more of these space rocks in our solar system and to be able to recognize that none are considered a threat so far. NASA has even successfully tested the possibility of moving an asteroid to deflect space objects if the time comes to need the skill.
There has already been proof that asteroids—big or small—have bombarded Earth in our ancient past, as geologists confirm about 190 (or more) craters around the globe. This also confirms that the cosmos were more violent in the past than they are today.
Vredefort Crater
One of these craters—the Vredefort Crater in present-day South Africa—was created when an asteroid about six miles (10 kilometers) wide smashed onto the planet some two billion years even before dinosaurs evolved.
Sudbury Basin
Another one from about 1.8 billion years ago, a giant comet slammed into present-day Canada. The impact basin is mostly eroded, but aerial views and radars make at least parts of the crater visible. Initially, the crater would have been about 120 miles (200 kilometers) wide.
Chicxulub Impact
This impact is famous as the one that became the end of the dinosaurs. Now 65 million years old, the site is buried beneath the Yucatan Peninsula and even appears as a gravity anomaly on maps, indicating how much the planet’s gravity field (dictated by mass) differs from a hypothetically similar surface.
The six-mile-wide asteroid crashed into shallow waters, blasting massive amounts of pulverized earth into the skies, resulting in climate cooling. In the end, not only did this impact kill the dinosaurs, but it killed off around 70% of the Earth’s species.
Arizona Meteor Crater
This crater on the list is relatively young compared to those mentioned above. This is because the asteroid that caused this crater crashed on Earth around 50,000 years ago.
The asteroid—around 100 to 170 across—impacted what is now modern-day Arizona. While this may also be considered small (again, compared to those we have already listed), David Kring, an impact expert at the Lunar and Planetary Institute, says that such an impact is enough to destroy a city the size of Kansas today.
Clearwater Lakes Craters
These craters found in Quebec, Canada, were caused by two asteroids that landed next to each other. Some researchers are still delving more into it, arguing that the asteroids did not land exactly the same time but rather separated by millions of years.
The impact sites are now lakes, with Clearwater West dating about 280 million years and Clearwater East about 480 million years earlier than the former.
Deniliquin Structure
There is a massive crater discovered in Australia, which researchers are proposing to be the biggest impact structure on Earth.
Named the Deniliquin Structure, this is believed to exist deep beneath the southeastern part of the continent somewhere in New South Wales. Magnet measurements indicate an enormous multi-ring formation underground, 520 kilometers across and around 320 miles in diameter.
Given these details, it can be said that this had an even more powerful impact than the one that killed the dinosaurs. More research is being done to determine the exact event and age of the impact.
These prove that the Earth is not only alive but also very active, especially during its younger years.
While we don’t have to worry that another Chicxulub impact will occur not until millions of years, it’s fair to be aware that, yes, asteroids still whiz past Earth every now and then, but that astronomers and researchers are constantly on their toes to ensure such “threats” are closely monitored.