Here's a fantastic simulation of a much bigger impact:
https://www.youtube.com/watch?v=zc4HL_-VT2YThe Tunguska Event
21–30 of 74 posts
Re: The Tunguska Event
#22Earlier quoted context omitted.
One interesting detail I found, I think, on Wikipedia, is that if the meteor had hit about four hours later, due to Earth's rotation, it would have roughly hit Saint Petersburg. If such events happen so frequently, we're pretty lucky so far. Given that much of Earth is covered in water, I could imagine a lot of these simply hit the ocean, but I don't know what would happen if it hit close to the coast.
a simple hit of ocean might be more devastating than hitting uninhabited parts of taiga. think about massive tsunami (at least that's what I would expect, depending on the impact force of course)
water is very dampening. tsunamis are from sustained force
Re: The Tunguska Event
#23I'm curious if we could mine in areas where large asteroids impacted and gets lots of minerals. Why do asteroid mining if we already have a few in the ground?
We do - Sudbury
Re: The Tunguska Event
#24I'm curious if we could mine in areas where large asteroids impacted and gets lots of minerals. Why do asteroid mining if we already have a few in the ground?
I saw a documentary a couple of years back which looked into a correlation of former (likely/suspected) meteor impact sites and natural resources. It looked like lots of areas rich in interesting metals/minerals turned out to probably have been hit by meteors in the past. So in a way, we are doing that already (at least if that documentary was not totally bogus).
New evidence for that: http://www.bbc.com/news/science-environment-14827624
Re: The Tunguska Event
#25A fun science fiction read is "Singularity" by Bill DeSmedt; the premise is the Tunguska event being a mini-black hole - and it's caught inside the earth, eating it from the inside out.
Re: The Tunguska Event
#26The scaling with meteor size is impressive. A 100 m object will flatten some trees in Siberia. A 10 000 m object will kill 75% percent of all species on the planet (the KT event).
Velocity matters too. E ~ mv^2 after all.
I'm reminded of Killing Star by Charles R. Pellegrino and George Zebrowski. Even without aggressive aliens, stuff falling toward the galaxy's central black hole may get ejected at relativistic velocity. Very unlikely. But we wouldn't see it until it was almost here.
Re: The Tunguska Event
#27> Given a long enough time period, there is a nearly 100-percent chance an asteroid large enough to destroy most life on Earth will impact our planet. No worries. Since quantum mechanics dictates that, given enough time, anything can happen, we can also say that given a long enough time period, life will spontaneously reappear.
A more interesting question is : what kind of delay is worth worrying about? I mean, for instance it is known that life will remain possible on Earth for about 500 million years, after which the Sun will be too bright. We don't seriously worry about it, since so many things can happen in half a billion years that it does not make much sense to try to plan or predict anything in such a timeframe. Similarly, I personal…
Reminds me of one of my favorite jokes.
The professor is lecturing, and says, "The Sun will grow to be a red giant, destroying all life on Earth in about a billion years...."
A distracted student suddenly sits up and cries out, "Oh my god!"
The professor says, "What's wrong? A billion years is a long time, you know. Nothing to worry about."
The student is visibly relief. "Oh, great! I thought you said a million years!"
Personally, I'd say a few hundred years is probably the reasonable max, maybe a thousand years. Beyond that, technology will be so incomprehensibly different that the risks and challenges will be completely different as well. What would be a civilization-killing asteroid today might just be "ooh, tasty resources already on a convenient trajectory" tomorrow. Or "aw shucks, it's going to make a big splash in the gray goo."
Re: The Tunguska Event
#28> With this in mind, we can view our future with some certainty. Something big is going to smash into us, sooner or later, and probably sooner.
I started reading Cosmos by Carl Sagan a week ago and he discusses the Tunguska event for several pages. It's an amazing book that I wish I had studied long ago. Had I not read that book, this statement would have instilled an impending sense of doom into me, which does nothing but demoralize me. Now that I've read that book, I can now tell with certainty that this prophecy is utter crap. As this article mentions, the asteroids are being tracked, so, we most likely will know it before hand.
OTOH, here's an article from science alert
http://www.sciencealert.com/next-month-an-asteroid-will-pass...
> Before you freak out, there's no chance that the asteroid is going to smash into us. The space agency is still determining its exact trajectory, but at the closest estimate, it'll be 18,000 km (11,000 miles) away as it passes us by - which would make it easily viewable with the help of a telescope. To put that into perspective, that's roughly one-twentieth the distance from Earth to the Moon. Alternatively, the asteroid could travel further afield, and pass us at a distance of around 14 million km (9 million miles).
> The reason for the big difference in these two estimates is that NASA only discovered this asteroid three years ago - hence the very-catchy name, asteroid 2013 TX68 - and haven't had much time to observe it just yet.
Re: The Tunguska Event
#29Here's a fantastic simulation of a much bigger impact: https://www.youtube.com/watch?v=zc4HL_-VT2Y
A few questions/comments:
* What is the "4 billion years ago impact" that is refered in the video? At first I thought it was the Theia impact, but the sizes and speeds don't quite match, and the simulation doesn't result in a second moon.
* It also mentions that it has happened 6 times. The only impact large enough I can remember of the top of my head that sort of matches that scale would be the canadian impact basin. A quick search on wikipedia tossed me to this list [0] but everything there seems to be on a different scale than what's described in the video. Are those impacts mentioned in the full program?
* It was recently reported that an expedition drilling in a part of the ocean where the crust is thin had found microbes near the magma, but I can't find any link. Given that it has been theorized even Venus may hold life in it's upper atmosphere [1], my guess would bethat, life is far more resilient than we imagine it to be.
[0] https://en.wikipedia.org/wiki/List_of_impact_craters_on_Eart...
[1] http://web.archive.org/web/20110807004311/http://gltrs.grc.n...
Re: The Tunguska Event
#30Earlier quoted context omitted.
Eventually you'll have to start worrying about very small but existential risks if you want any chance of preventing them. If the potential costs are as huge as they are with meteor impacts, I think the expected value of preparation is big enough.
The way to do this is to make it profitable to worry about it. Some say that certain asteroids are worth trillions. While they're probably not worth quite that much, they're a pretty penny. Investors might be interested in a company designed to capture and harvest asteroids. It will probably take a few centuries before that's a possibility, but it's interesting that it's probably just a matter of time before it doesn…
Someone trying to make it profitable: http://www.planetaryresources.com/#home-intro