# NASA spots asteroid on crash course with Earth – with just hours to go

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 …

1. #### Re: The only site that...

Yep with a name like 2018LA you would expect it to be a Hammer of God [(c)AC Clarke] aimed directly at that den of iniquity, Los Angeles.

1. #### Re: The only site that...

Or Lucifer's Hammer (Niven/Pournelle). Must re-read that....

2. #### Re: The only site that...

I near shat.

1. #### Re: The only site that...

Asteroid......headed to........planet...earth...........must try.....to stop............total destruction......of all...........mankind.

Mine's the one with the tribble in the pocket.

2. #### Gulp

"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.

1. #### Re: Gulp

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.

3. #### velocity of a sheep in a vacuum in El Reg units

Hmmm, is that an unladen sheep?

1. #### Re: velocity of a sheep in a vacuum in El Reg units

I don't know that, but it is an unladen vacuum.

2. #### Re: velocity of a sheep in a vacuum in El Reg units

The calculation also needs a correction factor for the drag coefficient caused by the difference between a sheared and an unsheared sheep.

1. #### Re: velocity of a sheep in a vacuum in El Reg units

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.

1. #### Re: velocity of a sheep in a vacuum in El Reg units

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.

2. #### Re: velocity of a sheep in a vacuum in El Reg units

To simply the calculations we set the wool drag to one. We also assume the sheep to be spherical.

3. #### Re: velocity of a sheep in a vacuum in El Reg units

African or European sheep?

4. #### Re: velocity of a sheep in a vacuum in El Reg units

More important than the drag coefficient (hint: vacuum=zero drag), is the speed of the Welshman chasing said sheep.

This was all sorted out a few years ago though, when El Reg units were standardised.

1. #### Re: velocity of a sheep in a vacuum in El Reg units

.... think I saw that "Report Abuse" button there somewhere. If I could just see more clearly through all this wool....

5. #### Re: velocity of a sheep in a vacuum in El Reg units

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

4. #### Passing the Buck

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.

1. #### Re: Passing the Buck

By deflecting the Asteroids we would be leaving all those lovely resources up there for future generations.

2. #### Re: Passing the Buck

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.

3. #### Re: Passing the Buck

Once the asteroids will hit them, why would they need trees, fossil fuel and all the other stuff that we consume/mess up?

5. #### Asteroid Ahhhhhhhhh......

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

1. #### Re: Asteroid Ahhhhhhhhh......

"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.

1. #### Re: Asteroid Ahhhhhhhhh......

...weponise approaching asteroids....OK. fine,

but what happens when we discover the enemy is us.

2. #### Re: Asteroid Ahhhhhhhhh......

@DataSource:

Do we really want to kiss our asses goodbye

While I'm not a big fan of mules or donkeys, I'm sure there are those who would want to .......

Mine's the one with "Our Furry Friends" in the pocket.

1. #### Re: Asteroid Ahhhhhhhhh......

> "Do we really want to kiss our asses goodbye"

I imagine many people will prefer a more 'proactive' stance in their final hours than merely smooching their own posteriors.

3. #### Re: Asteroid Ahhhhhhhhh......

Well, I, for one, would like the chance to drink the Bourbon and Scotch I have put aside for a special occasion. Then there's a little lady I know who might want to go out with a bang.

Is it me or does that asteroid in the picture clearly have a face?

1. #### Re: Big giant head

It's definitely you that has the face.

1. #### Re: Big giant head

Excuse me, did you just assume my physical appearance? How facist of you!

7. #### Asteroid Ahhhhhhhhh......

not sure I want to know if the BIG one is coming TBH

HOWEVER, if they could just tell ME, then I would be in the local market place shouting it out to all and sundry, screaming out

IF I AM WRONG, MAY GOD STRIKE ME DOWN RIGHT N ........................... :oP

1. #### Re: Asteroid Ahhhhhhhhh......

>>If they could just tell ME<<

I'd want to know - especially if there was enough time to max out the credit cards.

2. #### Re: Asteroid Ahhhhhhhhh......

Not only but also.........

https://regmedia.co.uk/2018/05/30/pompeii_skeleton_supplied.jpg?x=442&y=293&crop=1

8. #### Short Notice

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.

1. #### Re: Short Notice

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...

1. #### Re: Short Notice

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.

1. #### Re: Short Notice

Bernie? Where’s Bernie?

2. #### Re: Short Notice

"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/

3. #### Re: Short Notice

I wonder if the next thing we see is a rail gun used as part of a missile / asteroid defense shield.

Except that it takes a lot to get her up into space (and her girlfriend has to teleport her back to the surface afterwards) https://www.youtube.com/watch?v=8if4nVVtwUs

9. What's with the USian measurements? Next you'll be telling us the earth is 10,000 years old

10. #### El Reg Units

Why is the Register changing the units again? I'd just converted everything to rhinoceroses on skateboards - https://www.theregister.co.uk/2016/10/25/oz_trams_equivalent_to_30_skateboarding_rhinos/ and now you are switching to sheep. Standardise please!

1. #### Re: El Reg Units

@Hot Diggity

I believe the sheep in a vacuum was the very first official El Reg standard unit of measurement.

1. #### Re: El Reg Units

Is this at Pounds of Force or Newtons as we wouldn't want to overcook the chops?

11. > Not enough time to even call Bruce Willis and Armageddonoutofhere

That's a shame.

With a 6-foot asteroid, the plot may have actually been technically feasible.

1. While it's a shame we wouldn't have time to call up Bruce Willis, we should also be thankful that Ben Afleck would not have to be seen.

2. #### Armageddon outofhere

http://www.private-eye.co.uk/covers/cover-1037

12. #### I don't understand

"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.

13. #### dont be a panicky idiot

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.

1. #### Re: dont be a panicky idiot

I think the make up of the crew should be one man and 5 women for faster re-population...

1. #### Re: dont be a panicky idiot

Assuming you don't fire blanks, of course.

2. #### Re: dont be a panicky idiot

https://en.wikipedia.org/wiki/Inbreeding_depression

https://en.wikipedia.org/wiki/Minimum_viable_population

1. #### Re: dont be a panicky idiot

There are villages in the Somerset Levels that give both of those articles a run for their money.

2. #### Re: wasted money - a couple of months drifting in space at the cost of trillions

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.

14. #### The other side of the story...

I'm just surprised there was a webcam in what looks to be very remote Botswana, let alone anyone watching it.

15. #### A webcam in Botswana?!?

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 <-------)

16. #### "Meteor 2018 LA seen from farm..."

Hmm... looks more like 'swamp gas from a weather balloon was trapped in a thermal pocket and reflected the light from Venus' to me.

17. #### "...the rock in question was just six feet (two metres) across..."

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?

1. #### Re: Shall we plot a graph of asteroid size versus typical detection range?

Presumably an inverse square relationship is most likely...

18. #### The moon is a Harsh Mistress

Don't worry, It was just a test fire from our lunar friends on the other/dark side ...

1. #### Re: The moon is a Harsh Mistress

Anybody check the trajectory here? Are the Martians starting to fight back against our invasion of their planet by laser-wielding scout robots?

1. #### Re: The moon is a Harsh Mistress

Slowly, and surely, they drew their plans against us.

19. #### Are they zarking kidding???

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.

1. #### Re: Are they zarking kidding???

Could means that something is possible. So a few hours warning of impact could save lives. You folk from the south would probably just turn up in your trucks with guns and try and shoot the damn thing.

1. #### Re: Are they zarking kidding???

Could means that something is possible. So a few hours warning of impact could save lives.

That would depend on the accuracy of prediction of where it will land. Get that wrong and the authorities may well be evacuating people into the impact zone.

2. #### Re: Are they zarking kidding???

A bigger rock would be seen earlier. Extinction-level rocks hopefully years earlier.

3. #### Re: Are they zarking kidding???

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.

4. #### Re: Are they zarking kidding???

Those of us that aren't USAian know that it's possible to get around without a car. I can easily walk at 3-4 mph, so a few hours warning could let me get a decent distance towards safety.

20. >>>

strike somewhere in southern Africa, the Indian Ocean, or possibly New Guinea

<<<

>>>

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.

21. #### So...

... Nibiru was smaller (and later) than anticipated.

22. New Guinea?

You mean Papua.

23. #### just a tick

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

24. #### a strange definition of 'well ahead'

"predicted well ahead of the event itself"

yes, like a few hours warning...

25. #### Oh no, not again

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.

26. Why is the fact that it is heading towards us a problem for visibility? Surly position of the sun relative to us is, but presumably thats fixable with a satellite in a solar orbit?

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