NASA's asteroid orbit calculator spots a hot rock zipping past NASA's pleased with its still-under-development asteroid-hunting program after it spotted a 25-metre rock that buzzed Earth at about 1.3 times the distance to the moon on the weekend. Observatories like the ten-year-old PAN-STARRS at Maui in Hawaii scan the skies looking for uncatalogued little dots that might or might not be …
If Russia and America could launch their arsenal of nuclear missiles within 60 minutes of knowing an attack has been started, I think we could definately nuke an asteroid within 5 days.
Notice, however, I haven't said "destroy an asteroid". If it's that close, we're never going to move it off course. So we're going to be hit. But if we send up a few nukes that smashes the thing in to smaller, manageable pieces, it would at least spread the impact over a wider area.
Well the Russian and US (and UK) arsenals will be pretty good at nuking it when it has landed. Less good at hitting anything off the surface (or near surface) of the planet.
It does seem a bit harsh to nuke a city that's already had a 25m rock hit it from orbit, but hey, at least we will all get to join in the fun...
It's not just about targeting - you need a rocket that can poke it somewhere far away, like beyond the moon. Which means reaching something close to Earth's escape velocity of 40,000km/h. Unfortunately ICBMs are built for biffing things nearer at hand where such extravagant velocities aren't required and a mere 28,000km/h or so suffices for a quick lob to the other side of the world. Ditto for hypothetical orbital weapons - they'll either be built to deorbit and drop neatly on someone's head or for splatting a flimsy satellite or a passing ICBM.
What's needed is handing a great big bucket of cash to the usual aerospace suspects to build an IPBM. But be sure to sternly tell Lockheed not to go spending it on the F-35.
"Instead of having one massive rock hit in a vaguely predictable location, we have thousands of radioactive pebbles burn up in the atmosphere and coat the planet."
Realistically the added radioactivity from a "nuke the rock" scenario (which is unlikely to be successful) would be about a 0.01% increase in detectable planetary radioactivity. You'd have to be spectacularly unlucky to die from it.
"If Russia and America could launch their arsenal of nuclear missiles within 60 minutes of knowing an attack has been started, I think we could definately nuke an asteroid within 5 days."
A ballistic missile has enough energy to loft a lump of metal high into the air, but not into orbit. You really don't want to be letting off nukes only 600-800 miles above the surface (Think "EMP") with an intercept window measured in fractions of a second.
You need multistage rockets to intercept this kind of lump at a reasonable distance - which take weeks to assemble and get ready for launch - and even with a nuclear MOAB penetrator we still have no idea what would actually happen(*). These things are either pretty loosely held together (in which case the airburst scenarios that Craterhunter(**) has postulated might well sterilise a continent anyway) or solidly welded (in which case the effect would be minimal)
(*) A nuclear burst beside or on the surface of a rock or iceball won't have much/any deflection effect at close ranges so you're relying on breaking it up - and quite frankly without something a multiple of the Tsar Bomb'z size you're unlikely to have much effect(***)
(**) craterhunter.wordpress.com - this is the theory that a string of airbursting comet fragments ~10k years ago sterilised the North American continent and triggered the Younger Dryas cooling.
(***) Whilst the cold war doom scenario was multi-megaton bombs over cities using Castle Bravo as the example, virtually all nuclear weapons since the mid 1960s are smaller yield than Fat Man thanks to improved targetting meaning they simply don't need to be large to destroy their targets and those multi-megaton weapons simply don't exist anymore - which means months of work to build one. Even the modern stockpile of H-bombs are only 50-150kt dialable yield whilst "neutron bombs" (H-bombs with a Tungsten case instead of U238) are under 5kt. Most "conventional" nukes are in the 5-15kt dialable yield range and nuclear depth charges are around 0.3-0.5kt. These are enough to give the biosphere (and planet-side target) a "really bad day" but nowhere near enough to do much damage to a multi-billion ton rockpile.
I can visualize the mods required for the guidance software, that's not insurmountable although it should already exist if the military has tasked it. The far more interesting part, to the engineer, is the trigger, actually triggers plural. Those probably need a new design, although I can't see that being brought up in public. Hell, I'm not supposed to know anything about it either.
Do-able, less than 5 months, more than 5 days. Hey, on the bright side, it'd suprise the heck out of anybody just dropping in. Oh, make sure it/they go off pretty damn far off Earth. Wouldn't be great to EMP ourselves.
"Currently, five days notice will get us enough time to kiss our collective arses goodbye."
I prefer 'party like it's 1999' followed by standing at ground zero, watching the thing approach, and giving it a serious "digitus impudicus" with one hand, and with a bottle of tequila in the other...
The USA almost certainly has nuclear weapons in orbit. After the Challenger disaster, the Vandenberg Shuttle launch facility was abandoned. NASA restarted Shuttle flights, so the Air Force were reluctant to launch something on the Shuttle, but it can't have been people or regular payloads, so it might be reasonable to deduce they intended to use the Shuttle to service an orbital weapons platform. This role appears to now be being serviced by the X-37.
So could these weapons be turned outward? Could their guidance systems intercept such a fast moving object? Hopefully we'll never need to know.
"The USA almost certainly has nuclear weapons in orbit."
Doing so would breach almost every nuclear limitation treaty signed since the Cuban missile crisis.
The USA may be gung-ho, but it's not THAT gung-ho. The political stink if it was discovered would be unrecoverable - and there would be so many people involved that it's impossible to keep it secret for 50 years.
There are certainly nuclear power sources in orbit and even one nuclear reactor (it failed within weeks of orbit and has been up there over 50 years) but space is a demilitarised zone - which is why ASATS are a big deal.
Planet-killers are big, and we spot them quite a bit further out. Most likely, as they pass by us at a fair distance, then see that a few dozen orbits later, they might hit us. More observations usually get us a better estimate of the orbit; then we can say, "oh, that'll be a close miss, too." Read a bit about Apophis (large rock that comes close, but misses, in 2029, and which we thought might come back again in 2036 and hit us.)
We've also already found most of the planet-killers. Much of the current interest is in city or country killers, or Chelyabinsk-type events (breaks a lot of windows and could cause some deaths). For these, knowing five days ahead of time: "a big rock is going to land on this exact spot at this exact time" is useful.
Note that this short-term ability to figure out what's going to hit and what will miss is not new. It's only been used once, for the object 2008 TC3. That object, which was quite small, re-entered over northern Sudan and broke up into little pieces. It was very scientifically interesting (only time we've seen an object in space, tracked it, and found pieces of it on the ground), but unless a shard of it hit you right on the head, it wouldn't have been dangerous.
"Planet-killers are big, and we spot them quite a bit further out."
The vast majority of potential planetkillers we've discovered so far have blindsided us by coming from the direction of the sun and only been seen AFTER they've been past us and are on the way outwards
It's even harder to see a small dark thing in front of (or in the vicinity of) an extremely bright, extremely large thing than it is to see a small dark thing in a large dark space unless it's far enough away to be well lit by the bright thing.
At least not if what comes at us is a single giant rock, rather than many thousands of Everest sized chunks. Most of the blast will reflect off the surface, so while it might melt and vaporize a slight dent in the thing it isn't going to do much. There's no atmosphere to contain the shock wave like there is on Earth.
Instead of one giant rock hitting us, we'd have one giant radioactive rock hitting us, though we wouldn't live long enough for the radiation to matter. It might leave an interesting mystery if intelligent life evolved again in a billion years (no matter how big the rock, it would only affect surface life, subsurface life and hydrothermal vents aren't likely to be affected)
Come to think of it, is iridium a possible long term decay product of any theoretical type of nuclear weapon? :)
"Cutting the gap between first observation and orbital estimate won't make much difference if the incoming is a planet-killer, because we don't yet have a response - but when we do know how to handle an asteroid, having five days' notice instead of none will be important."
But surely, by the time we'll do know how to handle an asteroid, Bruce Willis will be retired or, well, dead?
I perfectly agree that a five day notice is much better than a "oh my God there it is !" notice, and I fully support any and all efforts to improve our species' awareness of any and all threats to this planet we call home.
In a totally different register (heh), buzzed ? It passes outside the orbit of the Moon and you call that buzzed ? Call me when it passes at an altitude of 60,000 brontosauri. THAT's buzzed.
I think the "5 days is better than no notice" thing is only true if it's for a truly catastrophic event. What happens if it's predicted that there's a 50% chance we'll all get smashed to smithereens in 5 days time, and then 5 days later the offending space rock misses us?
In the 5 day period enough people would be adopting enough of a 'go out with a bang' mentality to completely screw up the world. Imaging the effect on the global economy of a "we're all going to die...oh, hang on, we're still here" event
In the 5 day period enough people would be adopting enough of a 'go out with a bang' mentality to completely screw up the world. Imaging the effect on the global economy of a "we're all going to die...oh, hang on, we're still here" event
Do you think the denizens of the Middle East would stop the ever popular local hobby of fighting each other over nothing, at least for the party period, and join the global knees up?
Nope, I don't either.
Not sure blowing an asteroid into smithereens is going to be a solution. Nudging them to a safer orbit takes rather a lot of time, and five days is almost certainly not enough. Assuming bigger, planet-killer asteroids will be spotted long before these much smaller, 25m objects, we might still be able to calculate where the latter are going to land, and see if we can evacuate people. A 25m object is going to cause huge damage (especially if it lands in the see, causing a tsunami), but I do not think it is a planet killer.
More like "puny carbon-based life form killer".
Planet Earth is not going to be bothered by anything less than a stellar body barreling through and sucking it up or head-on smashing into it. A wandering black hole sucking it up would obviously destroy it without trace. The Sun, in a few billion years when it enters its Red Giant phase, just might engulf it in its atmosphere and melt it down. Otherwise, Planet Earth laughs at your puny asteroids. It will shrug off any impact, wait a few million years and spawn another bunch of life forms.
Current carbon-based life forms are much, much less resilient. And the threats do not come only from space, as this article points out.
Of course, space-based threats are not negligible either.
How fun, eh ?
A planet-steriliser would need to be several hundred kilometers across. We can see those already.
Chicxulub shouldn't have been a planetary extinction event - even with the concurrent deccan traps eruptions- and wouldn't have been if it hadn't hit on a shallow sea full of carbonate rocks.
That was truely a case of "spectacularly bad luck" for the dinosaurs, because without the vulcanism it still wouldn't have been an extinction event.
Advice: "run away… terribly fast."
That isn't advice specifically for a space rock impact, and of course it depends on it being possible to define "away" in the context of the incident. For a planet-buster rock there may be no "away", or, maybe just deep mines etc. to shelter in, like in some of the movies. But for a smaller rock, a continent cleanser or an urban redeveloper, mass effort may be worthwhile. Or at least to get a better view when it hits.
(In memoriam Adams, and Pratchett)
What we would really benefit from is a bit of a warning for the ones that hit with a 10kt to 10Mt explosion. Those are the ones that could make a country think it's been sneakily nuked and launch a retaliatory nuclear strike against it's enemies, causing a response from them and eventually fucking us all.
With a couple of days warning it'd be easier to avoid misunderstandings.
Wikipedia has a handy table: https://en.wikipedia.org/wiki/Impact_event.
This 25-metre rock is almost slap-bang (pun intended) in the middle of your range and five days would certainly be *helpful* if you had a really good trajectory. (In the panic, it might not be enough, but several million people get in and out of London twice a day, so it is certainly possible to evacuate a large city in time.)
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