99942 Apophis - Wikipedia This rock, Apothis, has flown near earth a few times. It may be a real threat.
See, I thought from the video that there was a rain of hot smoke, cinders and ash in front of the shockwave. If there isn’t, then it’s kinda a moot point “Would you spare you family from instant death by giving them an instant death?” Not much to debate there.
http://neo.jpl.nasa.gov/ If you are going to worry about space rocks, here is the official site. NASA will keep you informed.
Agreed.
If I had the time to do that:
Standing on a mountaintop in northern Siberia under the rapidly descending bulk of asteroid McAlmont, with a calculating expression and a baseball bat
If global destruction is utterly certain, Kim and I find the highest spot we can and cuddle while we wait.
Less seriously, I’m sure I’d be on the run from my family, who’d all be certain I had something to do with it, based on, well, my life.
OK, drop the hypothetical about the asteroid and answer that one right now. Death is inevitable: A hundred years from now, none of us are going to be alive, and most of us are probably going to die a lot more slowly and painfully than we would from any asteroid. And yet, we don’t all commit suicide to save ourselves the misery. We’re all postponing the inevitable. Well, if it’s worthwhile to postpone the inevitable for a few decades, why wouldn’t it also be worthwhile to postpone it for a few minutes?
Speak for yourself…I plan to be alive and kicking 100 years from now…
-XT
Because you might die badly at some point in the indeterminate future is different than you will die badly one hour from now.
I went to this site and put in the numbers. The circumference of the Earth is about 40,000 km, so you’d be about 20,000 km from the impact. I assumed the asteroid is made of dense rock and is coming in at 20 km/sec.
The first thing you’d feel would be the earthquake. It would be a 13.3 earthquake centered at the point of impact. It would reach you 20,000 km away about 67 minutes later. It would be comparable to the shaking experienced in the 1989 Loma Prieta earthquake in much of the Bay Area (the areas marked VI and VII on the map) The Bay Bridge, which collapsed, was in one of the areas hit harder than that. There may be more building damage, though, if you are in an area that doesn’t have good seismic building codes. I wouldn’t be too surprised to see bridge collapses in areas where seismic safety isn’t a big issue in building codes.
The shock wave would arrive in about 16.8 hours. The sound would be at 118 dB, and the wind would be at 1500 mph. That’s going to flatten anything left standing by the earthquake. The site doesn’t say if there would be cinders and ash blowing in the shockwave. 1500 mph winds are going to do a lot of damage even without those, though. That’s almost 10 times as fast as the winds in a Category 5 hurricane, more than 7 times as fast as an F5 tornado, and ISTR hearing somewhere that damage goes as the square of wind speed.
I wonder if you’d get some really interesting effects from the two shock waves converging on you at almost the same time…
Do watch out for the PDF at the bottom of that impact simulator page. It crashed my browser, and I had to re-type this whole post. Grrr. I hope a 500-kilometer asteroid hits them for that…
But it isn’t anywhere near 500 km in diameter. It’s about 270 meters. That’s probably not big enough to create global effects (a lot of experts think something about a kilometer in diameter is required for that).
Heh. I think my family would think the same thing “Anne! You have a degree in astronomy! Do something!”
Problem is, yes, it is easier to see something this big, but it’s also harder to deflect something this massive. Fortunately, there aren’t any Earth-crossing asteroids this big- 500 km is very large as asteroids go, and the ones that are this big aren’t on Earth-crossing orbits.
Hurry up and putt. The shock wave wont hit us for another minute.
Hey, it worked in FlCl.
Anne,
Finally! An expert! Tell me, would such a collision mean extinction for the human race? I’m approaching this from the assumption that death for me and my family is inevitable, is that a safe assumption? Also, did you watch the linked video? What did you think of it? Thanks!
Probably. Damage is generally proportional to energy, and energy is proportional to speed squared. But I’d be willing to bet that the coefficients change, too, when you go supersonic, and probably not for the better.
Oh, and that story with the baseball bat is great. I can’t help but have respect for someone who’d play the long shot odds, rather than just giving up hope.
I’ve got a couple bottles of really nice wine that need to be consumed pronto.
:o
I would say almost certainly. I think Ralph Nader has a better chance of winning the presidential election in a landslide than the human race has of surviving an impact by a 500 km asteroid. It would certainly cause a mass extinction event. We think the asteroid that killed the dinosaurs was 10 km in diameter, and this is much bigger than that.
Very safe. One book I’ve read about the K-T impact (the dinosaur killer) says that 99% of all individual organisms on Earth probably died in it, possibly within a few weeks of the impact. Not 99% of species, 99% of individual organisms. And this impact is much larger than the K-T impact.
My undergrad advisor has a solar system impacts page, too. I plugged a 500-km asteroid into that, and it said that the impact would release enough energy to boil the Earth’s oceans (this is an effect the other impact simulator site doesn’t take into account). If that happened, I would confidently predict that all life on Earth except maybe for some bacteria and thermophiles would become extinct. I don’t know how long it would take for the oceans to start boiling.
Very, very cool (though I had to watch it on my husband’s Mac- my computer didn’t want to let me see it). I think most of it seems pretty plausible. Debris would be ejected into low Earth orbit, and would fall back down, so global firestorms are a possibility.
One thing was a bit misleading- the end line saying it had happened at least 6 times in Earth’s history. Perhaps it did, but impacts with an object that size would only have happened fairly early in the history of the Solar System (and there were probably more than 6 of those). There aren’t 500 km Earth-crossing asteroids out there now.
This would be my thought, too.
This reminds me of this great Patton Oswalt routine. Relevant part at the 4:35 mark.
It wouldn’t be glowing hot like in the video, would it? The asteroids in our solar system are just losers who didn’t join a gang a become planets and would have cooled a long, long time ago if I’m not mistaken.
I’m a non scientist, but I would think the heat would come from the tremendous kinetic energy released in the collision. Or am I remembering physics class wrong (always a distinct possibility)?