The following is a possible concise summary:
This video explains the origin, detection, and impact of asteroids that could hit Earth. It discusses the examples of Chelyabinsk and Barringer Crater, as well as the extinction of dinosaurs. It also evaluates the possible ways to deflect or survive an asteroid strike, and concludes that the best option is to find them early. The video is sponsored by Kiwico, a company that creates educational projects and toys for kids.
Here are some key facts extracted from the text:
1. An asteroid heavier than the Eiffel tower exploded over Chelyabinsk, Russia, on February 15, 2013, injuring 1500 people and damaging thousands of buildings.
2. Scientists had predicted that another asteroid, known as Duende, would make a close flyby of Earth on the same day, but they missed the unrelated one that hit Russia.
3. Since 1988, over 1200 asteroids bigger than a meter have collided with Earth, and only five of them were detected before they hit.
4. Asteroids are the leftover debris from when the solar system formed four and a half billion years ago, and some of them are rocky while others are mostly metal.
5. Most of the asteroids have stable orbits between Mars and Jupiter in the main asteroid belt, but some have made their way closer to Earth and are known as near-Earth objects.
6. Stephen Hawking considered an asteroid impact to be the greatest threat to life on Earth, but finding asteroids is difficult for several reasons, such as their small size, low reflectivity, and unpredictable orbits.
7. Barringer Crater in Arizona was formed by a 50-meter asteroid that released the energy equivalent of 10 megatons of TNT, over 600 times the energy of the Hiroshima bomb.
8. The dinosaurs were wiped out by a 10-kilometer asteroid that hit about 65 million years ago, which launched debris into sub-orbital trajectories and caused global heating and fires.
9. There are no 10-kilometer asteroids with a path that intersects Earth for the next 100 years, but there are many smaller ones that could still cause massive damage or obliterate a large city.
10. There is no effective way to deflect or destroy a kilometer-sized asteroid at the moment, and even evacuating a city in case of an impact is very difficult. The best thing to do is to look for them and monitor their orbits.