Professor Gretchen Benedix says that asteroids aren’t spiky and don’t have debris clouds around them. She also says that it’s hard to steer your spaceship to avoid asteroids and that landing on one is different from landing on Earth.
Asteroid movies – summary and main points
[01:51]
To blow up an asteroid 20 kilometers across, you’d need to use 4,000 50-megaton bombs. The biggest thing we’ve ever exploded on Earth was 50 megatons.
A shock wave is a pressure sound wave that travels through space. An asteroid hitting the Earth 65 million years ago would not have caused a shock wave.
[03:33]
The asteroid belt is not a doughnut of rocks that are that close together. Some asteroids get knocked out by other asteroids, and some get smaller over time.
There’s a mission called DART that’s trying to take a small asteroid and see if it will change its orbit in any way. The movie takes a different tact and says that it missed, but that smaller-sized objects can fly by.
[05:49]
I would be surprised if he didn’t hear it, because that would be a very loud rumbly noise that you would kind of notice before you saw the light. The thermal radiation would be felt before the shock wave, and the effects would be burning.
A comet is a smaller body than an asteroid, and it can cause a fireball that can be seen on Earth. We should build shelters because this could devolve into governments making choices about randomly picking people to save and then finding shelters for them.
[08:28]
We’ve never witnessed something this size hit a terrestrial planet. It would be more like a fireball and then a trail of smoke behind it, and the impact would cause a shock wave that would go well beyond breaking your eardrums.
Meteor showers are really tiny specks of dust that are burning up in the atmosphere. If you see a fireball, stand there until the very last possible second, because you might be able to jump out of the way.
[11:28]
A meteorite is a rock that came from space that might glow as it’s coming through the atmosphere. It might smell, but it’s really cold and if you get burned by it, it’ll be freezer burn, not heat burn.
The Peekskill meteorite hit the boot of a car in New York in 1992, but the meteorite was not alive. We haven’t found any evidence of life on a meteorite so far.
[13:49]
The odds of anything hitting water are really high on the Earth, and a tsunami wave that high would take a long time to reach the shore.
“Deep Impact” is a movie about a comet that might hit the Earth. It would destroy the Earth, but it wouldn’t break it apart.
[16:41]
The probability of something this big-hitting the earth is so small because the solar system has evolved over time.
