The only site that...
...I forgive for clickbait headlines.
Scientists at NASA's Planetary Defense Coordination Office have made a rare sighting – an asteroid on a collision course with Earth. The rock, dubbed 2018 LA, was picked up by the Catalina Sky Survey on Saturday morning, just hours before it piled into our home world at a speed of 10 miles per second, or 0.5368 per cent of the …
"0.5368 per cent of the maximum velocity of a sheep in a vacuum"
I initially processed that as being slightly over 1/2 the speed of light. I was wondering how tiny the asteroid was, given that I didn't notice any massive fireballs encircling the Earth (I follow XKCD's what-if series enough to know that I don't want to be near* anything moving at near relativistic speeds).
*near= on the same planet as.
Well, if it was traveling at ~1/2c speed, the asteroid upon impact will be dumping around 0.15 of the equivalent of its rest mass as ENERGY. With 2gr/cm3 average density on asteroids and a volume of a ~1 meter radius sphere being 4.2m3, that is a rest mass of 8.4 tons. The energy release will be ~1.1 10^20 Joules or ~27000 Megatons...
6400 megatons is the estimated yield of the nuclear global arsenal on year 2009 which is a 4.2 ratio.
Glup indeed.
If the sheep is in a vacuum, then it's sheared status becomes irrelevant.
If in doubt, refer to Commander David Scott's experiment on the moon when he dropped a feather and a hammer.
If you doubt the moon landings, refer yourself to the Bursar for some dried frog pills.
The fact the sheep is sheared or unsheared is very pertinent. Mine are awaiting the clippers at the moment and I would estimate their cross sectional area to be 4 or 5 times that of when they are sheared. Given the mass will barely chance during shearing their acceleration due to light pressure from the sun in vacuo will be a mere 25% when sheared.
I think even you would notice the difference between a sheared and unsheared kebab after a few aeons if it smacked you in the face on a Saturday night.
I am more worried about where this vacuum is and what affect gravity would have on said maximum velocity of a sheep.
If the vacuum (and therefore sheep) is in my Thermos then that explains the sounds coming from my lunch bag today.
If not then I guess my wife is still pissed off with me and I am not going to be eating O.o
By deflecting all these asteroids, we're just creating a higher concentration of them for future generations. I'm already using up all the trees, burning all the fossil fuels, and digging up all the heavy metals that future children are going to need. Now I'm complicit in bombarding them with rocks that I should have taken myself.
Thanks, boffins.
By deflecting all these asteroids, we're just creating a higher concentration of them for future generations. I'm already using up all the trees, burning all the fossil fuels, and digging up all the heavy metals that future children are going to need. Now I'm complicit in bombarding them with rocks that I should have taken myself.
Serves them right for not cleaning their room and for not going to bed on time...
...and for that crappy nursing home they stuck you in when you got senile.
Ahhhh not that again,
what, who it is likely to hit this time, decimate some trade competitor, make a big splash and sink the small islands, I'm surprised that many aren't cheering at the prospect.
Asteroid Lotto !!
Seriously though, do we want to know that we're going to be flattened by an asteroid.
Do we really want to kiss our asses goodbye
"what, who it is likely to hit this time, decimate some trade competitor, make a big splash and sink the small islands, "
Weaponise approaching asteroids. Brilliant idea - if they're big enough to cause damage (but not big enough to cause extinction) we don't have to fully deflect them, only deflect them enough to ensure they hit our enemies.
A few hours notice for a dim 2 metre rock to be identified as inbound from the dark is impressive given the limited resources being used. If this had been another 20 metre lump like the Chelyabinsk meteor there might even have been a crater to point at and ask for some serious funding for a useful early warning system.
I wonder if the next thing we see is a rail gun used as part of a missile / asteroid defense shield.
I mean being able to hit an inbound projectile with a massive enough bolt from a rail gun, it should shatter the asteroid in to smaller fragments that would continue to burn up...
I wonder if the next thing we see is a rail gun used as part of a missile / asteroid defense shield.
I'd rather not - it will spend most of its time rotated 180 degrees opposite to any potential incoming asteroids.
I mean being able to hit an inbound projectile with a massive enough bolt from a rail gun
This will work only if the asteroid is solid enough. If you have a large chondrite rock or a piece of a comet core consisting mostly of ice it will absorb the impact or let the slug go right through. Though on the positive side, these are likely to disintegrate in the upper atmosphere so they have to be really big to do any damage.
"shatter the asteroid in to smaller fragments that would continue to burn up..."
Believe it or not this would probably be _worse_ than a single solid object coming in.
Craterhunter's website covers this scenario: https://craterhunter.wordpress.com/the-planetary-scaring-of-the-younger-dryas-impact-event/a-thermal-airburst-impact-structure/
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"It is also only the second time that the high probability of an impact was predicted well ahead of the event itself."
So they're calling a few hours well ahead of the event? I mean it can take me that long to wake up in the morning so I'm not convinced it's that useful a time span.
No need for any additional resourses to be wasted on a space program to save anyone (certainly nobody you actually know or like would be chosen) to survive a couple of months drifting in space at the cost of trillions
Just make sure the space station is always staffed by a man and a woman plus some sort of escape pod to come back to earth when the dust has settled.
People on Earth can make thier own individual plans if they want like a shelter stocked with snacks
to wait it all out and a couple of books to read.
Maybe assisted by a grant from all the trillions saved to help out usefull people like wot work in the city looking at numbers on a screen or talk bolloxs about some invisible particle they are excited may exist.
I think the point is rather that such a space program might /eventually/ allow a viable survival route - but you wont ever get that survival route without starting to build up the basic knowledge and infrastructure.
Nee ou, kry julle feite reg! Daar's nie webcams in Botswana nie.
According to Netwerk24 it was " ’n veiligheidskamera van Vikus van Zyl, wat op die plaas Rietvallei tussen Hartbeesfontein en Ottosdal boer,"
(source: https://www.netwerk24.com/Nuus/Omgewing/kyk-boere-op-soek-na-meteoriet-in-deelpan-omgewing-20180603)
(Ottosdal is that way ------>
Botswana is that way <-------)
So there's no lower limit in size to make the news?
OMG!! There's a small pebble burning up in the atmosphere, with no advanced warning.
OMG!! There's a small rock, that we just detected 26 seconds before impact.
OMG!! There's our present 2m rock that we detected only hours before.
OMG!! There's a 10m rock that we detected only days before.
etc.
Shall we plot a graph of asteroid size versus typical detection range?
So NASA thinks a few hours notice could save lives? Somebody smokin' crack!
Daily traffic is bad already, but at least it's all spread out over hours. Announce an asteroid inbound and you'll generate a huge clot of traffic all at once. That will paralyze all but the smallest and most remote towns. When they show miles of stopped cars in disaster movies, they're being accurate for a change.
Specific example: Here in the Deep South where snow is uncommon and shallow, we don't maintain armies of snowplows like up North. A good winter storm can make our roads impassable, and everyone knows it. So when a winter storms threatens icy roads, most people head for home, and perhaps to pick up their kids at school. The sudden surge has paralyzed traffic more than once. In one such incident last year, I knew people who didn't get home for ten hours.
When we have a few DAYS notice, that might help. A few hours can be worse than useless.
Nobody said "NASA thinks a few hours notice could save lives".
This one was only detected a few hours before because it's really small and consequently of no danger (as was shown a few hours after detection).
Larger, and consequently more dangerous, ones are much easier to spot.
>>>
strike somewhere in southern Africa, the Indian Ocean, or possibly New Guinea
<<<
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Even a couple of hours of notice could greatly reduce the number of casualties in the event of an cosmic prang.
<<<
Are we expecting the populations of these ares to take cover under the nearest table?
As a response plan, and factoring in the speed of the object as described, this all seems a bit woolly.
There seems to be a discrepancy between the caluclator and the article, which state that the [maximum] Ssx is c/100 and c/50, respectively. If I enter 299,800 km/s*, it returns 10,000% of maximum... trimming to 2,998 km/s returns 100% of maximum, while the article clearly states 5,995 km/s. What did I miss?
* confirmed by typing "c" into Qalculate. suddenly I wonder if they would accept a Reg units patch... and if they're among those fleeing Github
When a serious civilization-threatening asteroid approaches, our best bet right now is to either leg it or batten down the hatches, and make sure we have a space program to keep some survivors safe off-world.
To preserve the species from an impact capable of destroying civilisation, you need a colony with sufficiently large population and industrial base to be ENTIRELY SELF-SUFFICIENT on decadal to century timespans. Spoiler alert: never going to happen/.
(By "self-sufficient" I mean "capable of building and launching crewed interplanetary spacecraft from scratch, starting with digging out the titanium ore".)
Bear in mind too that incidence of quality engineers is maybe 1 in 10,000 of the population.
See what I mean? NEVVVVVER GONNA HAPPEN.
I have to pick the troll icon even though I'm perfectly serious and this is surely obvious to anyone with half a clue who thinks about the problem for 5 minutes, because there are an awful lot of Trekkies here who seem to think it's a documentary.