Every 80,000 years, a meteor approximately 300 meters in diameter strikes our planet. Small asteroids hit our planet constantly, and larger ones with the potential to wipe out life on Earth have struck our planet in the past, and will undoubtedly threaten to do so again. So it's not a question of if a meteor big enough to destroy us will be spotted on a collision course, it's a question of when. The evidence is on the surface of our planet - she's taken a beating from massive asteroid collisions in the past; leaving enormous, eerie craters and millions of fossilized creatures dead from the blast. The evidence is in the stars - NASA can now spot asteroids big enough to destroy us and several of these objects have come within a hair's breadth of Earth on the astronomical scale.
They say we shouldn't worry about these life-ending meteors, and that crossing the road has a much higher chance of killing us. But how much do we really know? Scientists say that 99 percent of life-threatening asteroids out there are currently undetected. We "common folk" are not trained in astrophysics, we don't have access to the Hubble telescope. We are completely at the mercy of what NASA tells us. And that begs the question: If there really was an asteroid big enough to kill us all and it was heading straight for us, would they tell us? The logical thing to do would be to keep it secret, so as not to start global panic and chaos. So the truth is, you might never see it coming...
15 Comet Hyakutake
This comet came extremely close to wiping Earth off the galactic map in 1996. It is also known as The Great Comet of 1996. It came so close that you could see it clear as day with the naked eye, and it was as beautiful as it was terrifyingly dangerous. It was a whopping 2.6 miles in diameter, and it also had the longest tail ever observed on a comet. Adding to its overall weirdness, it was also found to shoot out X-rays, caused by some strange reaction between solar winds and its atoms. It came very close to the Earth, and it was only 9.3 million miles away at its closest approach. That may seem like a long distance, but in astronomical terms it just barely missed Earth. For example, if it had been hit by another asteroid and had moved slightly, it would have hit Earth and resulted in a mass extinction level event.
14 2000 FL 10/Asteroid 86666
This asteroid came within 15 million miles of Earth. It is 1.5 miles wide, which would have resulted in a global cataclysm if it had hit. Again, that is pretty far off but it could have easily struck Earth if something had altered its orbit slightly. In October 2015, it passed by without incident. This asteroid was first spotted 16 years prior by students at the University of Arizona. A slight nudge, and this "harmless" meteor would have killed billions of people in an instant. The rest would also be threatened by earthquakes and possibly tsunamis. The next time it comes around on its orbit, we might not be so lucky...
Asteroid 2014-YB35 is the size of a small mountain, and it just barely missed Earth. It was March of 2015 when this asteroid skimmed by our planet. How close did it come? A minuscule distance of about 4 million miles. That's a little too close for comfort! And the worst part? This asteroid, like many other asteroids, is on a continuous circular orbit. That means it will keep coming back around, again and again. And the next time this asteroid comes around, it will be even closer to our planet. They say the next time it passes by Earth, it will be in 2033, and it will come 3 million miles within our orbit. All it takes is something to slightly knock it closer to Earth, and we're looking at an entire country getting wiped out, and that's if we're lucky.
12 1950 DA
This asteroid had one of the highest probabilities of hitting the Earth of any asteroid. It's about 1 km in diameter, and NASA scientists have been worrying about it for some time now. It once had a 2 percent chance of hitting Earth. That's huge! Since then, they've done some calculations and are now saying it's less likely to hit our planet than they previously thought, but the threat is still massive and it's still one of the asteroids that is most likely to hit Earth. Part of the reason for this is due to the fact that it will pass through an asteroid belt on its way to Earth. That means it could bounce around off other asteroids, potentially knocking it onto a direct collision course with Earth. They just don't know what's going to happen. The one saving grace? It's scheduled to pass Earth in the year 2880, so you won't be alive to experience it. Who knows, maybe by then our descendants will have figured out a way to stop it...
This asteroid was named after an ancient Egyptian mythological demon, and NASA is worried that this "demon meteor" will bring about the end of our civilization. When they first spotted the planet, it looked to have about a 3% chance of hitting Earth. This was back in 2004, and it's scheduled to pass by the Earth in 2029. Not only that, but there is also a possibility that Apophis will pass through what's known as a "gravitational keyhole." If the asteroid goes through this region of space, it's guaranteed to strike the Earth 7 years afterwards, in 2036. This asteroid set the record for reaching the highest likelihood of any asteroid to strike the Earth, reaching level 4 on the Torino scale. After a few improved calculations, NASA is now saying it will miss us by 14 to 35 million miles.
10 Planet 9
Planet 9, otherwise known as Planet X, or "Nibiru" by conspiracy nuts, is one of the biggest mysteries in the solar system. And whatever it is, the Earth might one day collide with it. Even more disturbing, there are theories that Planet 9 has impacted the Earth many times in the past, and there are even people who say that the moon is a piece of Planet 9 that broke off last time it hit the Earth. Its existence is only a theory, but there is some evidence. Everything in a certain region of our solar system seems to be pulled towards something with a massive gravitational pull, and a large planet like Planet 9 would explain that. The strange thing is that every 26-27 million years, almost all life on Earth is destroyed. One theory is that these extinctions are caused by either an impact from Planet 9 itself, or Planet 9 striking the Kuiper belt and knocking icy asteroids towards us every 20,000 years.
The asteroid that has been nicknamed "Bennu" poses such a huge threat to Earth that NASA has unraveled a plan to land on the asteroid and explore it with robots, in an attempt to learn more about the asteroid that might one day destroy us all. It's as wide as the Eiffel tower, and it's travelling at 63,000 mph. If it hits, it's going to hit hard. The plan is to land on the asteroid, collect samples, and then return to Earth and try to figure out a way to stop it. It could hit us in 8 different scenarios, from 2169 to 2199. Although it's much smaller than other asteroids headed toward Earth, it's travelling faster and still has the potential to cause huge amounts of dust in our atmosphere, possibly creating an artificial winter that could last for years.
8 Manicouagan Crater
This massive crater is a reminder to humans that huge asteroid impacts have happened before, and they can happen again. 215 million years ago, an asteroid 5km wide caused this, and now it's the largest crater that is clearly visible on the Earth, and the sixth largest crater on the Earth. It is located in Quebec. It has been suggested that the asteroid that created this massive hole is responsible for the end-Carnian extinction event. One thing is certain, every life form within the impact area would have died instantly, with more dying from the shock wave from miles from where the crater was created. This definitely would have been a mass extinction event, if not globally then within a huge part of the Earth.
7 Woodleigh Crater
There is some debate over how large the Woodleigh crater actually is. Some say the crater, located in Australia, is only 60 kilometers wide. But others say that that's only the center of the crater, and there is a larger impact zone around that, making the crater over 120 kilometers wide. If that's true, then the meteor that caused it must have been over 5 kilometers wide. This crater was created over 365 million years ago, and that date is very close to a mass extinction which can be seen in the fossil record. Over 40% of life on Earth vanished around this time, and some people say there was more than one meteor involved.
6 Acraman Crater
This is another crater that formed in Australia. They estimate an asteroid hit this area almost 600 million years ago. This period of time is known as the Ediacaran period. There was a lot of life before this asteroid struck, but they were small and most of them were microscopic. After this asteroid touched down, much of the life was destroyed. The explosion would have been incredible. However, it seems that the Acraman impact might have been responsible for actually changing the course of life as we know it. After the impact, these life forms seem to have changed dramatically in order to adapt. So this meteor could have destroyed life, but instead it seems to have hastened its evolution.
5 Chesapeake Bay Crater
Just by looking at the crater, you can see that whatever caused it was one hell of a meteor. This meteor struck the Earth 35 million years ago in the Atlantic Ocean. It was travelling at over 70,000 miles an hour. Everything along the East Coast of America was destroyed instantly, and marine life died out in a massive extinction level event. The asteroid was over a mile wide. This is certainly big enough to trigger a worldwide extinction of life on Earth, and scientists believe it is responsible for the Oligocene extinction. Even more scary is the theory that this was part of a meteor shower that lasted for two million years, and this impact was just one out of many. This impact would have caused darkness from the dust blotting out the sun, acid rain, and wildfires.
4 Popigai Crater
This crater in Russia is evidence of a meteor strike that almost definitely would have caused a mass extinction event. It seems to have coincided with the last major extinction level event in the Earth's history: the Eocene extinction. It is the fourth largest crater on Earth, and it may have been caused by an asteroid of up to 8 km in diameter. The Eocene extinction has been theorized to have been caused by a rapid change in the Earth's climate, and a meteor impact of this size may have caused that. It wiped out most of the snails and sea urchins, but it had a huge effect on mammals. Whales died out but were replaced by more modern whales, and the evolution of mammals was set on a course that would eventually lead to the evolution of humans.
3 Chicxulub Crater
This underwater crater in the sea outside of Mexico was left behind by a seriously massive meteor that would have had devastating effects on Earth's life forms. It's the third largest crater on Earth, and it's over 180 kilometers in diameter. The meteor that created it was more than 10 km in diameter, and the blast it created was over a billion times the energy of the atomic bombings of Hiroshima and Nagasaki. That's 2 million times more powerful than the Tsar Bomba, the largest nuke ever detonated. It would have created the largest mega tsunamis in history. It struck 66 million years ago, making it the likely cause of the Cretaceous–Paleogene extinction event.
2 Sudbury Basin
The Sudbury Basin, located in Ontario, Canada, is the second-largest impact crater on Earth. It's 250 kilometers in diameter, meaning the asteroid that caused may have been up to 15 kilometers in diameter. It must have struck in a shallow ocean, and its effects on life at the time must have been intense. Because this crater struck 1.85 million years ago, life on Earth would have been relatively primitive. Scientists think that the meteor caused the oceans to heat up because of cooling molten rock underneath, and this might have caused life to go in a completely new direction. Researchers are now saying that a similar meteor strike could have actually been the spark that created life in the first place, 3.8 million years ago.
1 Vredefort Crater
The Vredefort crater in South Africa is the largest impact crater on Earth. It's 300 km in diameter, and the meteor that created must have been 15-20 kilometers in diameter. This makes it one of the biggest meteors ever to strike the Earth. This impact occurred 2 billion years ago. Like the Sudbury Basin, it must have had a serious effect on life forms on Earth, no matter how primitive. If an asteroid of this size hit Earth once, it can certainly happen again. Can you imagine what would happen to humanity if something like this happened today? I'll give you a hint: We would all die.