2024 YR4 - ~50m Asteroid

[Solocle]

I don't see a thread about this one and it's starting to make the mainstream press. As of time of writing, a 2.3% chance of hitting Earth on 22nd December 2032.
Nuclear weapon could be used to defend Earth - Sky

If it does hit, the energy released will be on the scale of a thermonuclear bomb, an order of magnitude bigger than Chelyabinsk.

It's currently rated 3 on the Torino scale - the uncertainty is in its timing, the orbit is confined to a long narrow band and matching impact corridor.

[eharding]

Estimated energy release equivalent to 7.7 megatonnes of TNT vs the 50 megatonnes of the Tsar Bomba, so we've inflicted worse than 2024 YR4 on ourselves already, although obviously not near any population centres. You still wouldn't want to be anywhere near where it hits though.

[Solocle]

eharding said:

Estimated energy release equivalent to 7.7 megatonnes of TNT vs the 50 megatonnes of the Tsar Bomba, so we've inflicted worse than 2024 YR4 on ourselves already, although obviously not near any population centres. You still wouldn't want to be anywhere near where it hits though.

Yup, although still substantial uncertainty on that figure, it could range from 40-90 metres in diameter depending on its albedo (we're trying to tell how big it is from how bright it is without knowing how black it is).

At the low end it's about 2-3 MT, at the high end it's about 40 MT.

It's likely to airburst, but on the larger end fragments hit the ground, potentially with a couple of MT of residual energy.

Using the nominal 53m 7.7MT figure, it's likely to airburst at 20-30 thousand feet. Also depends on the approach angle.
Some figures
Pretty much the worst case scenario would be a direct hit on somewhere like Mumbai, which I believe is in the danger area.


This is virtually the absolute worst case scenario, obviously an evacuation or redirect can be planned with 4 years+ notice.

Nukemap

[Bright Halo]

Giant tennis racquet?

[Simpo Two]

Can't use nuclear, bad for the environment...

The asteroid will, however, make 'man made climate change' look pretty fking insignificant if it hits!!

[Solocle]

Simpo Two said:

Can't use nuclear, bad for the environment...

The asteroid will, however, make 'man made climate change' look pretty fking insignificant if it hits!!

It won't have any major global effects. It could wipe out a large city, absolute worst case scenario - and if nothing is done about it. Far more likely it gives a couple of farmers a bad day, and far more likely still some fish...

And nuking it in space wouldn't have any environment effects. And nukes aren't even that radioactive if the launch fails, it's a bit of a pain to cleanup is all.

[Some Gump]

Why a nuke?

All we need is bruce willis in a vest, that dude out of platoon, and an aerosmith cd. Job jobbed!

[Terminator X]

"a 2.3% chance of hitting Earth on 22nd December 2032"

Can it really be tracked with that accuracy almost 8 years away?

TX.

[Ozzie Dave]

Shame its not earlier in the year- here in Brisbane the Olympics progress is a disaster, lots of talk and more talk, a few months earlier and it could save them the problem. I vote we task Elon with solving the issue, I'm sure the US will come up with a solution for themselves or decide that it wont affect them.

[peterperkins]

If within a few years we accurately estimate it as having a 100% chance of impacting mid ocean 100's of miles from any land, would we bother doing anything about it apart from set up loads of remote observation platforms etc etc to watch and record the spectacle??

[Solocle]

peterperkins said:

If within a few years we accurately estimate it as having a 100% chance of impacting mid ocean 100's of miles from any land, would we bother doing anything about it apart from set up loads of remote observation platforms etc etc to watch and record the spectacle??

I think we'd let it hit in such a case. The danger with an asteroid redirect mission is you might not be able to make it miss completely 4 years out from impact. Therefore trying to nudge it could likely make it worse.

Terminator X said:

"a 2.3% chance of hitting Earth on 22nd December 2032"

Can it really be tracked with that accuracy almost 8 years away?

TX.

Yes it can. Solar eclipses can be predicted with pinpoint accuracy centuries out. The problem with this object is we've only been observing it for a few months, and it's moving away from us.

The result is that we know most of its orbital parameters very precisely, to the point where we can narrow it down to a corridor a few hundred miles wide. The uncertainty is in the timing, by multiple hours.

More observations narrow that down, and when it comes back around in 2028 we'll know very precisely.

Edited by Solocle on Wednesday 12th February 07:59

[Portofino]

If it hit the ocean wouldn’t there be a huge Tsunami wave or waves with the potential for more and fairly random destruction????

[Solocle]

Portofino said:

If it hit the ocean wouldn’t there be a huge Tsunami wave or waves with the potential for more and fairly random destruction????

I don't believe that's a major threat, it could make a big splash, but once you're 100 miles away the wave might be a metre or so high. Most of the energy will be dissipated in the atmosphere.

[SpudLink]

Terminator X said:

"a 2.3% chance of hitting Earth on 22nd December 2032"

Can it really be tracked with that accuracy almost 8 years away?

TX.

When this was raised in the media I heard a scientist say something along the lines of ‘we are tracking and the estimate will be become more accurate as we have more data’. Which seems about right.

[Portofino]

Solocle said:

Portofino said:

If it hit the ocean wouldn’t there be a huge Tsunami wave or waves with the potential for more and fairly random destruction????

I don't believe that's a major threat, it could make a big splash, but once you're 100 miles away the wave might be a metre or so high. Most of the energy will be dissipated in the atmosphere.

I think still best to try & re-direct……the risk of the known & un-knowns are too high.

[Solocle]

Portofino said:

I think still best to try & re-direct……the risk of the known & un-knowns are too high.

The effects of a couple of megatons of energy being deposited into the ocean isn't that far beyond the realm that we have experience with.

Try a redirect in 2028 and we won't be sure of the precise impact it has until 2032.

[Simpo Two]

Solocle said:

It won't have any major global effects. It could wipe out a large city, absolute worst case scenario - and if nothing is done about it. Far more likely it gives a couple of farmers a bad day, and far more likely still some fish...

I was thinking of it landing on ground and throwing up vast amounts of dust into the air - like Krakatoa etc, which wiped out a summer.

quote=Solocle]And nuking it in space wouldn't have any environment effects.

Of course, but there will be woolly-headed econuts campaigning against it because it has the word 'nuclear' in it.

[Solocle]

Simpo Two said:

Solocle said:

It won't have any major global effects. It could wipe out a large city, absolute worst case scenario - and if nothing is done about it. Far more likely it gives a couple of farmers a bad day, and far more likely still some fish...

I was thinking of it landing on ground and throwing up vast amounts of dust into the air - like Krakatoa etc, which wiped out a summer.

Solocle said:

And nuking it in space wouldn't have any environment effects.

Of course, but there will be woolly-headed econuts campaigning against it because it has the word 'nuclear' in it.

Krakatoa was 200 megatonnes, and as an eruption, particularly prone to raising dust.

It probably won't hit the ground at all, and certainly not with major force.

[Simpo Two]

Solocle said:

It probably won't hit the ground at all, and certainly not with major force.

Odds are that it won't hit us at all, and if it does, it will land in the sea. No point trying to guess from this distance but it's a good headline.

[Solocle]

Simpo Two said:

Solocle said:

It probably won't hit the ground at all, and certainly not with major force.

Odds are that it won't hit us at all, and if it does, it will land in the sea. No point trying to guess from this distance but it's a good headline.

Of course, just saying that even if you take the absolute worst case scenario with this one, it isn't that bad in the planetary scheme of things! It's certainly no Chicxulub.