I teach my students about dinosaurs to help with their reading – dinosaur names are AWESOME for practicing phonics skills and being able to correctly say them is a great motivator for them. There is also something about these huge creatures, that we are now totally safe from, that captures the imagination of both children and adults.
Question always crop up when we look at these readers and one of those questions is ”how big was the asteroid that killed all the dinosaurs”. For a long time I used to just say it was very very big and it was going very fast, well after one student asked me how big is very big I did a little research and next lesson gave him the answer.
The meteor that is thought to have killed the dinosaurs, is estimated to be about 10 to 15 kilometers wide. It created an impact carter of over 150km across, called the Chicxulub crater due to the speed it was travelling, at about 20 km per second. Which equates to 72000 kilometers an hour.
The difference between and comet, an asteroid and a meteor.
A little refresher for us all. I knew there was a difference but I had forgotten what they were.
A comet is a made of ice, rock and dust and orbits the sun.
An Asteroid is made of rock, the most hang about between Jupiter and Mars in the asteroid belt
A Meteor or meteorite are smaller chucks of comets (usually) that either burn up in our atmosphere (meteors) or make it to the planet’s surface (meteorite)
So how big was the meteorite that killed the dinosaurs?
Official estimates are that the meteorite that caused the extinction of the dinosaurs was approximately 10 to 15 Km across. Because it was so fast it caused a huge crater though, that is over 150 km across. That is the second biggest crater we have found on earth. This would have thrown up massive amounts of debris, dust and dirt into the sky, caused tsunamis and fires all over the world. In the area of the impact the devastation would have been total but that wouldn’t have killed all of the dinosaurs. The dust and debris in the air would have impacted plant life which would then impact the animals who relied on the plants for food and then of course the carnivores who ate the herbivores would have suffered as well. Although we are not sure how long it took in years for dinosaurs to go extinct, we do know about 75% of all life disappeared during and shortly after this event.
The resources for Dinosaurs and space are on the site if you are a teacher looking for supplementary materials. We have read along videos with them as well. Oh.. and they are free 🙂
Though I paraphrased that of course!
How fast was the meteorite that wiped out the dinosaurs
The speed of this meteroite was a big factor in the devastation is caused. At 72000km an hour, which is about 20km a second!, it was fast for an impact and caused the huge impact crater. As mentioned all the debris it kicked up caused the blocking or filtering of the sun for an extended period of time. Asteroids / Meteors can travel from about 35000 Km an hour to about 200,000 Km an hour!!. Just for an example that’s around the world 5 times in an hour…
What was the angle of impact
Recent studies have theorized that the angle of the meteor could have been a key factor in the cause of the all the damage and dust. In fact the angle has been suggested to be about 60 degrees, which scientists say is basically perfect if you want to throw up as much dust and dirt into the sky as you possibly can. SO with the speed, the size and the angle those dinosaurs didn’t really stand a chance!
What is the biggest meteorite to hit the Earth?
Well its hard to say, luckily the evidence of really big impacts is in our distant past, and we should be thankful for that! The biggest crater on earth is from 2 billion years ago and is called the Vreredort crater and is located in what is now South Africa. It is suggested that this meteor was a similar size to the one form the Chicxulub impact and there is ongoing debate about which actually caused the largest crater. Although both would have been devastating for life on the planet.
However these are the 10 largest craters on earth we have found
When I say ”we” I mean people, I had nothing to do with it!!
|Name||Location||How long ago||Size|
|Vredefort Crater||South Africa||2 billion Years||190 Kilometres|
|Sudbury Basin||Canada||1.8 billion Years||130 Kilometres|
|Acraman Crater||Australia||580 Million Years||90 Kilometres|
|Woodleigh Crater||Austrlia||364 million years||40-120 Kilometres|
|Manicouagan Crater||Canada||215 Million Years||100 Kilometres|
|Kara Crater||Russia||70 Million Years||65 -120 Kilometers|
|Chicxulub Crater||Mexico||65 Million Years||170-300 Milometres|
|Popigai Crater||Russia||35.7 Million years||100 kilometres|
|Chesapeake Bay Crater||USA||35 Million Years||85 Kilometres|
Are any Asteroids, Meteors or Comets close to Earth?
The next question that follows on from how did the dinosaurs die and how big was the meteor that did it is ‘’are there any close to Earth or are there any that will hit Earth’. The quick answer is we don’t know 100%, or yes there are hundreds that pass close to Earth but to make sure they don’t have nightmares you can quantify this answer a little.
Nasa and other space agencies are constantly searching the skies for near earth objects that could hit Earth and they have gotten a lot better at it in recent times. For example only today (the day before the American election) there have been reports that there will be a fridge sized asteroid (2018 VP₁ )that has a 0.5% chance of hitting either us or out atmosphere, and then in 2048 (2007 VK184 ) another larger one that may be on a course to shoot past us.
The bad news is it’s a big old sky and its difficult to spot something moving at 20000 km an hour its small, the good news if its big enough to see then we can probably see it! What we do if it is heading our way, well that’s a discussion for another day.
Also just to so they know its it not the stuff of movies, we get hit by about 48 tons of ”space dust” every single day. It is not uncommon, and its why they can see shooting starts in the sky.
About the Author
Hi I’m Marc. A teacher of over 15 years, mostly English but dabbled in outdoor pursuits and media. Thought is was about time to sharing both what I have learnt during that time and the resources I have put together. On this site we aim to teach the theory and share our thoughts, but also go that one step further and give you access to the hard resources you need for your class or for you children. Feel free to take a look at our resources, email us on firstname.lastname@example.org, or jump on the Facebook group to ask questions. Happy learning, teaching or playing!