Planetary Defense?! It's not just Mars that will kill you. If the aliens don't get you, the asteroids will. All that stands between us and the sad fate of the dinosaurs is likely to be a giant rocket ship that Elon Musk and a bunch of guys in pickup trucks just kind of throw together in a Texas field somewhere. Saving the whole damn planet!! http://blogs.esa.int/rocketscience/2019/04/25/hypothetical_impact/ https://twitter.com/esaoperations/status/1122972721598672904 https://cneos.jpl.nasa.gov/pd/cs/pdc19/ https://cneos.jpl.nasa.gov/pd/cs/pdc19/day1.html https://cneos.jpl.nasa.gov/nda/ https://www.space.com/asteroid-impact-simulation-nasa-planetary-defense-2019.html https://www.iflscience.com/space/nasa-and-international-partners-are-running-an-asteroid-impact-simulation-this-week/ https://bgr.com/2019/04/29/asteroid-simulation-nasa-fema-exercise/
As a Stargate fan, it's kind of cool that there's actually a Planetary Defense Conference. But as someone who likes living, I'm glad this press release is just an exercise and not the real thing.
The Day2 Briefing Book is pretty fascinating. It goes into a lot of detail about what parts of the world are at what kind of risk. (The equivalent of a multi-hundred-megaton nuclear airburst, with thermal and blast effects, tsunamis, and all kinds of bad stuff. Then it looks at various deflection scenarios, what kind of orbits might work, the uncertainties involved and more bad stuff. Download it here: https://cneos.jpl.nasa.gov/pd/cs/pdc19/pdc19_briefing2.pdf
A good question. (Would you rather be shot by a bullet or by buckshot?) Breaking it up would make each impactor smaller and hence less dangerous. But there would be more of them and probably less certainty about their impact points. That would complicate evacuations of areas deemed to have high impact probabilities. BTW... page 9 in the briefing book (link in the post above) doesn't look too good for northern Ohio. The whole northern tier of Ohio is included in where a direct hit is possible in their scenario. If that happened, it would be deemed 'Unsurvivable'. If these predictions hold up as the simulation unfolds, then residents of your area could probably evacuate to an area with a lower probability of getting hit. But... if the thing was broken up into a number of still dangerous pieces, it might be harder to predict where a safer spot might be.
and while we're at it, allow me to introduce the God of Chaos https://www.geek.com/news/nasa-giant-god-of-chaos-asteroid-will-fly-past-earth-in-2029-1785300/
I don't know if it makes all that much difference if the mass is in one lump or divided up into gravel. Apparently the energy released and the resulting heat and blast would be similar. (It seems to be a function of the amount of mass and amount of deceleration.) In their scenario they are succeeding in characterizing the oncoming asteroid. It's supposed to be a contact binary (humm... wonder what made them think of that?) about 200 meters across. Estimated to release 510 megatons of energy when it hits Earth, 25 times the size of a large Cold War H-bomb. Not a planet-killer, not even a continent-killer. But potentially (in the US context) a state-killer (especially one of those New England micro-states). Dunno how much of a tsunami it would kick up if it impacted the ocean. https://twitter.com/esaoperations/status/1123713706007957507 Here's some estimated results if it landed on Denver:
Their simulation had them send out a recon spacecraft in 2019 to observe, track and better characterize the incoming asteroid. By 2021 it sends back information allowing more precise impact data, showing that it will land right on top of Denver. (Which will get rid of those damned Colorado Avalanche, Rockies, Nuggets and Broncos... there's always an upside.) They say (on December 30, 2021), "NASA plans to launch two rendezvous spacecraft.. toward 2019 PDC next spring that will arrive at 2019 PDC in November 2023. They will gather data that will enable experts to more precisely determine the asteroid's mass, density, porosity and structure. These data are vital to the success of any deflection efforts. Before the two spacecraft are able to arrive at 2019 PDC, 23 months from now, a fleet of six kinetic impactor spacecraft will need to be built and launched by NASA, ESA, JAXA, and the Russian and Chinese space agencies, who all participate with the international Space Mission Planning Advisory Group (SMPAG) that was established for the purpose of collaborative efforts to mitigate an asteroid impact threat. The kinetic impact technique involves hitting the asteroid with a spacecraft to incrementally slow the speed of the asteroid to deflect it off its impact course with Earth." Besides NASA and the national space organizations, I'd guess that SpaceX and its Falcon Heavy and Blue Origin with its New Glenn (which should be flying by then) would be on the case too. India too. The agenda at the Planetary Defense Conference today (Day 4) seems to suggest that they are planning for the likelihood that the above efforts aren't successful and today they are concentrating on the consequences of asteroid impact and disaster management. They would presumably have several years to totally evacuate Denver and a large area of 4,000-5,000 square miles surrounding it, including important places like Boulder. They will have to move the state government, banks and so on. They will need to organize an orderly mass exodus of millions of people over a short period. There will be panic and huge economic effects as a major US city (and much of its state) are taken off-line, local property values drop to zero, vital industrial plants are threatened (with supply-chain effects), communications and transport effects (Denver is the Rocky Mountain hub) and on and on. Will they declare martial law and put the Army in charge? Where will they house everybody? (New Orleans will probably have some useful lessons for them. The evacuation there went surprisingly smoothly, the problems were with the people left behind. Nobody left behind in Denver will survive.) They will have to figure out how threatened Colorado Springs and Ft. Collins are and maybe evacuate them too. https://twitter.com/esaoperations/status/1123974717264809986
If a rock that big were going to hit Denver, and I had a few years to prepare, I'd worry about it triggering Yellowstone, and I'd be sure to be in the Southern hemisphere when it hits.
Bible talks about this, in Revelation. "...a great star, blazing like a torch, fell from the sky on a third of the rivers and on the springs of water— the name of the star is Wormwood. A third of the waters turned bitter, and many people died from the waters that had become bitter." Blazing star that fell from the sky? Sounds a lot like either an asteroid or a nuclear bomb. Either one would probably taint the water supply and pretty much everything else and very likely kill billions
Sorry, New York . . . https://gizmodo.com/nasa-accidentally-destroys-nyc-in-attempt-to-save-denve-1834614030
