What Would Happen If Asteroid Bennu Hit Earth?

[@monostripeexplosiveexplora2374]

I just realized that we have started asteroid mining... now it is only a small step towards a pirate base in one!

[@Becka_Harper]

YAAAAAAARRRRRRRR!

[@VaxzaLimeIsCool]

Hell yeah!!!

[@Vespuchian]

Nice to think your average mining setups would only need shovels instead of drills or rock breakers.

[@CausticLemons7]

I'll donate to your Space Pirate Asteroid Base Kickstarter!

[@AndrewJonkers]

@@Vespuchian Exciting times!. Given the gravity, it is more like shoveling grain while standing in a grain silo - sounds easy till you try it. You can literally jump off this asteroid to escape velocity as I recall (0.7km/hour) so you can throw rocks to the hopper on your mining ship "in orbit". The big problem is almost all mining equipment relies on gravity and/or atmosphere for correct operation so there are whole new technologies needed to make space mining happen.

[@theCodyReeder]

Crazy idea but is there any possibility of changing the asteroids trajectory so that it gets a gravity assist off earth that sends it into another planet? This would remove possibility of future impact and we could study/use the impact somewhere else.

[@alexsiemers7898]

It could probably be redirected to hit the moon with a future impact, and that wouldn’t take nearly as much deltaV as it would to make it encounter Venus or Mars, even decades later.

[@wurfyy]

Even modern spacecraft need course corrections to get to other planets because of our limited precision. The effect of a gravity tug on the course of an asteroid being absolutely glacial, I think it's really unlikely this could be done. Maybe if Mars just happened to be in exactly the right place at the right time, I suppose. A better idea, if a collision becomes too likely, would be to just blow it up well in advance so we'd get another annual meteor shower instead. No need to fool around with gravity tugs and junk like that.

[@dng1576]

NASA is trying something like that with DART. But their aim only is to change the course of an asteroid so that it wouldn’t hit earth

[@thetraitor3852]

It is year 2060 we are talking about. We most likely won't look at it as a threat anymore, but as free resources for the Earth's orbital economy. Smashing it into anything is a waste.

[@epicspacetroll1399]

@@wurfyy On the contrary, I think the effect of a gravity tug being "absolutely glacial" would make it easier to do. Small adjustments could be made throughout the entirety of the months long "burn" based on tracking updates. And there's a major problem with the "blowing it up" strategy. What are you going to do it with? Nukes? Might be good for a last ditch effort, but otherwise you're now going to be showering Earth with radioactive gravel and boulders, when you could have not showered Earth with anything by redirecting it. That's not to mention a gravity tractor or similar device would undoubtedly be much less expensive than a space nuke, and cause much less international controversy.

[@Scotracer1987]

Hi Scott. I'm another Scott, from Scotland and I studied Aerospace engineering :)

[@Scotracer1987]

But your calculation on kPa to Bar is wrong. 1 bar is 100kPa (1x10^5).

[@5777Whatup]

You got beat by another comment by the way...

[@lonegroover]

Ah but you weren't .. :)

[@spacenoodles5570]

Scottland

[@MrSmithSAH]

You're the backup

[@josefkrakel9136]

7:25 Thanks for blowing up Rockville MD. The traffic there is terrible anyways.

[@anarchyantz1564]

Would anyone really notice?

[@michiganengineer8621]

I was hoping for the POI to be Washington, DC myself.

[@kevondaye8125]

Its 2020. DO. NOT. TEMPT. THE. MAGIC. BOULDER!

[@apyr1439]

Im sure this will be the year where we will an IRL Deep Space Kraken

[@fridaycaliforniaa236]

LMAO, the green one from KSP ?

[@wormhole331]

@@apyr1439 I read that as Deep Space Karen.

[@fridaycaliforniaa236]

@Dave P. Meanwhile, we have already nice options with the Coronavirus lol

[@1TakoyakiStore]

Wow. Dusting off the classics. I approve!

[@ArifRWinandar]

"So without even trying, we have actually changed things." Pretty much sums up the history of humanity on Earth.

[@whatjake7898]

I’m sorry but humans have done nothing but change things on purpose. Look at housing developments they used to be forests and damns that have created lakes. We’ve actually done the opposite of your comment.

[@neithere]

@@whatjake7898 humans did not plan to screw up the climate, flood all the major coastal cities, kill themselves with hunger and heat and cause wars due to overpopulation and mass migration. Some are even trying to deny that this scenario is already in progress. No, humans just want a new thing, and that other new thing, and the new thing which that guy has, and also some fun and money. Bam! Catastrophe.

[@whatjake7898]

@@neithere As someone with an Environmental Science degree I cannot tell you how inaccurate and uneducated this comment is. Please stop expressing your opinion until you get some critical thinking skills.

[@neithere]

@@whatjake7898 First, please stop expressing your opinion about other person's skills until you learn a bit about those. Second, please stop trying to stop others in expressing their opinions. Third, please do tell me how inaccurate that opinion was. Not that my comment was completely serious, but I wonder what exactly made you so upset. Is it the scale of the projected future events or the causality?

[@whatjake7898]

@@neithere You're spreading misinformation. I will not stop calling out those who do zero scientific research before opening their mouths. Maybe you should stop spreading inaccurate information if you do not want to be judged negatively based off your opinions you post online. I'm not STOPPING you. Just making a suggestion so you stop making yourself look like a fool. And upset? You will have to let me in on the software that lets you hear the tone in my comments. I'm just trying to educate the uneducated.

[@pkramer962]

* 5:55 100 bar is 10.000 kilopascal

[@scottmanley]

Lol I knew that... wtf

[@clementpecheux1586]

Yes it's supposed to be 1 bar

[@scottmanley]

I dropped the correction in because I missed ‘kilo’ and just messed things up even more

[@clementpecheux1586]

Nice video anyway

[@pkramer962]

@@scottmanley I haven't been studying for long, but if I have learnt anything then it's probably this conversion ratio. :D

[@Cannon1221]

Mass is mass. When talking about the different types of asteroids hitting Earth a teacher once told us to imagine a shotgun slug vs bird shot.

[@rasaecnai]

man that is so american

[@NikovK]

A shotgun slug across a field will kill you. Bird shot across a field bounces off your jacket.

[@Bobbie_1999]

@@rasaecnai Most American thing ever xD

[@neithere]

Did your teacher suggest to imagine shooting soda cans across an American football field?

[@faroncobb6040]

@@NikovK This isn't like shooting across a field, Bennu is about 0.25 KM across and if the atmosphere was uniform density it would be 8.5 KM deep, so if a bunch of bird shot or a shotgun slug is an inch long the protection offered by the Earth's atmosphere from Bennu would be equivalent to the protection 34 inches(0.8meters) of air would give you from the bird shot. At that distance there is basically no difference between a load of bird shot and a slug. Edit, I saw 262 meters and didn't bother to read that that was radius instead of diameter, so Bennu is actually about 0.5 km across and earths atmosphere would be as effective as 17 inches(0.4meters) of air between the shotgun muzzle and yourself.

[@Marci124]

"One ton of solid iron has the same kinetic energy as one ton of loose gravel" "Ah dohn get eht."

[@AdrianFreakout]

"But iron 's heavier than gravel."

[@gontzi7]

But look at the size of the loose gravel, thats cheating

[@alexandresen247]

@Mycel it's jon snow

[@bonbin6053]

Gravel is like.. 200g less dense than iron... so iron must be heavier.... I don’t get it

[@Fantaman900]

mass times speed is energy. simple. doesn't matter what it is made off. even something as light as a pingpong ball can hurt if it hits you fast enough

[@KpxUrz5745]

It's just incredible to be able to witness a body like Bennu up close and in detail. Very educational.

[@aarone9000]

And the educational aspects; totally wasted on 80% of our population!

[@Aengus42]

It's the old school kid maths question, "What weighs more, a tonne of iron or a tonne of feathers?"

[@OscarSommerbo]

Answer: Drop it on your toes and tell me which hurt more.

[@Electroblud]

Actually, the ton of iron. On earth anyways. They have the same mass but not the same weight. The feathers have more volume and thus more buoyancy in the air, making them weigh a few grams less.

[@wvance0316]

@@Electroblud That's mathematically impossible unless you are talking about the rate of acceleration outside of a vacuum. They weigh the exact same since they were being set at equal weight before you mess with it. You are thinking of force, which is mass times velocity, which is why it would hurt more to have steel dropped on you rather than feathers (outside of a vacuum that is).

[@Electroblud]

@@wvance0316 Ah, you weigh them at 1 ton inside the atmosphere? Then the feathers actually have more mass. Since you need more of them to counteract their buoyancy. I am not talking about atmospheric drag. Think about dropping a piece of wood in water vs a piece of steel. Under water, the wood actually has NEGATIVE weight. Weight being the downward force an inert object at rest applies to whatever it is resting on.

[@Becka_Harper]

Depends, which is metric and which is outdated?

[@Ryan123220]

Unrelated to the actual content of the video... 8:08 is such a beautiful way to display inclination

[@alquinn8576]

i'm inclined to agree

[@TS-jm7jm]

@@alquinn8576 you.. you.. ugh just take my like.

[@snozzmcberry2366]

Oh yeah. I didn't even notice. Kerbal Space Program should take notes.

[@Ryan123220]

@@snozzmcberry2366 I hope to see it in KSP 2, if not it seems like a reasonably moddable thing.

[@FranktheDachshund]

@@alquinn8576 nature abhors a pun

[@dreyna14]

Given the "rubble pile" composition, how would tidal disruption during approach to Earth impact affect the spread of the overall mass as it entered the atmosphere? I would expect that in the last minutes the breakup would make it more difficult to reach the ground. Of course, this would all depend on things like approach angle and overall relative velocity.

[@Kualinar]

Unless the angle of impact is very shallow, like

[@theelectricwalrus]

My guess is that it the size of the asteroid is large enough to generate significant tidal forces, the asteroid is so large as to be extinction-level

[@prjndigo]

More to the point is the energy states of the magnetosphere and the fact that Bennu has no cohesion at all. A good portion of it would likely go into orbit and slaughter our satellite system.

[@Daniel-yy3ty]

@@theelectricwalrus he meant the tidal forces on the asteroids, not us

[@maxnaz47]

@@prjndigo Exactly, i'm hearing very few references to Kessler syndrome in all this. Diverting a large loose body mass, no matter how expensive, is still better than letting it make us earth bound for quite some time...

[@TheAlpha6echo]

*Humans see an asteroid* “You know... I really wanna poke it with a stick.”

[@Yora21]

Poking with a stick is the natural instinct to science.

[@tach5884]

@@Yora21 As long as you write it down.

[@Mikey-ym6ok]

Yora you’re not wrong

[@Jibberellin]

Marvelous summation of the human condition. . . and why we beat the dolphins to civilization!

[@benedictroberts678]

@@Jibberellin That and thumbs; those aquatic nerds can suck it.

[@Flinsyflonsy]

We need Bruce Willis on this problem, stat.

[@Shifticek]

Good thing Bruce Willis with scottish accent is already on it

[@wayne.edward.clarke]

I like this channel for a number of reasons, not least of which is the absence of sponsor's spiels and Patreon shout-outs. I congratulate you on having a channel that is successful without them.

[@dreadfullink2279]

If that hit Buenos Aires i can see the Mobile infantry being deployed to Klendathu

[@Jonassoe]

I'm from Buenos Aires, and I say KILL 'EM ALL

[@sophdog1678]

I'm doing my part!

[@monostripeexplosiveexplora2374]

The only good bug is a dead bug!

[@harrisonmckenzie4905]

C'mon you Apes do you want to live forever!!?

[@Keex11]

At least it'll have a kickass soundtrack.

[@lovt16]

Just wanted to remind you that your are by far the most consistent, entertaining, and interesting KZbinr out there

[@robertosaba8813]

Thank you Scott for the amazing content! You have inspired me to want to study aerospace engineering!!!!

[@kutafas]

Thank you, Scott. These videos of yours help me to survive on this planet. ❤

[@Marinealver]

A most fitting end for the year of 2020

[@CompoundNila]

lol

[@JordanLane7]

1st time here, you’re a great storyteller/lecturer (whatever the word is) great video bro!

[@michaeldoughty1782]

I think it would take the edge off my day fore sure.

[@casey01494]

Yup, pretty sure this would check a box on 2020’s to-do list. Interesting video! Awesome job as always Scott!

[@hamsterdave4852]

With it being so loosely composed, could a kinetic impactor be a viable option to disrupt it a few days/weeks/months before it impacted the earth, distributing a big portion of it's mass over a much larger area? I'm now imagining Elon hitting the thing with a Tesla Roadster on an escape trajectory from Earth.

[@Electroblud]

You'd need a pretty ludicrously huge kinetic impactor for that. This asteroid still is around 500m in diameter after all. It's a small mountain's worth of gravel.

[@Electroblud]

Actually, I just did the math: a 10 ton impactor going 440m/s would have enough kinetic energy to blow apart the asteroid. Not actually that bad. Surprisingly achievable. Or is my math wrong? I used the formula for gravitational binding energy from Wikipedia.

[@lucas29476]

@@Electroblud Your math checks out. However, note that blowing it up has the possible side effect of the pieces all individually entering Earth, putting a similar amount of energy into Earth EDIT: the Grav Binding Energy is a theoretical minimum. In practice, your input energy will be (very) unevenly distributed and thus maybe leaving still big chunks

[@Agnemons]

@@lucas29476 Doesn't matter what you do the total energy released will be the same. However "How" you release that energy matters alot. Spread over a large enough area you would have a spectacular slow motion train wreck as against an even more spectacular instantaneous wreck. (I am referring here more to the long term effects of heat and dust on the Earth)

[@AndrewBlack343]

If you broke it up far enough away would you not be able to ensure that most of the fragments missed the earth?

[@RafaelFaenir]

Thanks for the amazing video, Scott! One question, why use a 1 ton "tug-spaceship" if in some years we (might) have a 120 ton Starship (SpaceX) that could in theory do the job? I guess those studies need some new calculations to make up for this new possibility ;) (One more idea in the list of "once/if we have Starship, why not just throw it at every space problem we have?")

[@Notheggerwarsauber]

Hey Scott, don't you think it's interesting that asteroids always seem to hit craters when they collide with earth? Maybe you could do a video about it?

[@scottmanley]

Tunguska and Chelyabinsk didn’t hit craters

[@5777Whatup]

@@scottmanley they didn’t collide with earth either.

[@toddmccarter45]

@@5777Whatup sure they did, the atmosphere still counts

[@agtshaw]

Asteroids are naturally attracted to holes that they can fit it because they need to find shelter

[@5777Whatup]

@@toddmccarter45 geologist don’t study air, they study earth like rocks and dirt, therefore we have a very clear definition of what it means to hit earth. They hit organic matter though! But, geologists don’t study pines either... 🤔

[@BogeyTheBear]

0:35 I'm fairly certain Bennu is held together _constantly_ by gravity, not once per week... 😉

[@AdmiralBob]

They even leave it on on weekends.

[@crimson7676]

Since they changed hours the gravity is now being serviced on Thursdays.

[@MushVPeets]

inb4 we accidentally gravity-tractored it into ourselves while OSIRIS-REX was keeping itself parked above the asteroid waiting to take a sample

[@InfinityToPlanck]

Correction there have been multiple natural disasters of greater scale in just the last thousand years any volcanic eruption of VEI 7 (more than 100 cubic kilometers of material ejected) is easily in the 10 gigaton range. The most recent is the eruption of Mount Tambora (33 gigaton equivalent) in 1815 which caused the Year without a Summer, global crop failures and killed at least 71,000 people just in the immediate vicinity of the eruption. Not saying impactors are a non issue just that volcanos of VEI 6-8 are a more frequent threat of comparable scale to all but the largest impact events.

[@ednelson9913]

Ok now your just giving 2020 ideas

[@vast6056]

2060, 2020's rerun

[@VaxzaLimeIsCool]

@@vast6056 2020 is no doubt the new normal.

[@julanomoralesmapping3372]

booo

[@topsecret1837]

@@vast6056 what about 2040?

[@zoltankurti]

Just imagine the year 202020. We have to spread out quickly in our galaxy, because the events in 202020 won't just affect a single star system.

[@TheZoltan-42]

There is also the chance that the first close encounter is not an impact, but close enough to pull Bennu apart into a string of smaller asteroid balls, "spreading" it into a long chain of less dangerous but higher chance impact objects.

[@deep.space.12]

It would just be Tuesday in the grand scheme of 2020.

[@CompoundNila]

true

[@stefanschneider3681]

Again and again: Complicated matters perfectly explained! This way even an educated amateur like me get‘s an idea of what‘s going on! Thanks!

[@why_though]

When I close my eyes I can still hear this guy saying AIR-th

[@peterpicroc6065]

Yes, and "beuster". Love it!

[@theallknowingorbitalteapot1010]

Really loving the frequent uploads, this content is great

[@MoonWeasel23]

I just read the part of Nemesis Game where the asteroids hit. Incredible timing!

[@redbandet]

Dude spoilers

[@caidenw1]

I was amazed the author tried to get us to sympathize with anyone associated with the free navy after that shit.

[@axelandersson6314]

Scott accidentally said that 100 bar is equal to 100 000 pascal as opposed to 1 bar being equal to said amount. He also said that 1 atm is 100 pascal as opposed to 100 000, but he said the figure for ton-force per meter correctly.

[@FQP-7024]

I'll tell you what happens. We finally have the sweet release of death. Edit: ok guys I get it i made yi uall laugh a little bit but it's about enough with the likes we have to prep stuff if something happens so we survive the fallout.

[@BodhiSoftMobileApps]

If you haven't already done an episode on this, it'd be interesting to see an EROEI analysis of mining asteroids for rocket fuel, including the energy needed for orbital capture around wherever the rockets needing the fuel would be (moon, Mars, etc.) vs. energy needed to orbit-match, mine it in situ, and retrieve just the (at least somewhat refined) fuel.

[@julese7790]

*"un kg de plume vs un kg de plomb" INTENSIFIES*

[@tomf3150]

English please. Sérieusement.

[@shreyasp3287]

Sir your videos help many of us whose parents didn't went to university please continue your work and keep inspiring us

[@skorpiongod]

Now we're asking the real questions

[@clank4001]

Very interesting video, and that Lunar Rocket model /Legos? behind you is awesome!

[@Ryusennin]

Disclaimer: the video thumbnail is not to scale.

[@cooleosis1]

great video, i never thought of drag as kinetic energy because of the weight of the air before

[@ramziel]

1:50 Oh, I know that by watching GrayStillPlays

[@eriklinde1506]

Your "Hello, It's Scott Manley here!" was so energetic and my speakers just a bit too loud that it woke the baby in the next room :D :D

[@flamingmohmohawesome4953]

7:17 Woah! Why did you put the blast zone there? The Secret Service would like to know your location.

[@boring7823]

Um "Rock"-ville ?

[@HylanderSB]

That face when Scott uses my home area for his destruction chart. Not that I haven’t done that myself about a dozen times with various nuclear explosion simulators.

[@Miata822]

"Saving the Earth." What Science is for.

[@Tailspin80]

Saving the earth? I think you’ll find the earth will be ok whatever happens. Humans not so much.

[@SRSR-pc8ti]

Iain M Banks wrote such great sci.fi. Miss him.

[@bagochips1208]

civilized species digging up big boned monkes 65 million years later: interesting

[@Tubluer]

Hi Scott, don't know if you'll see this but I'll give it a try. *RE:* Spacex static fire with sparks I noticed that none of the sparks passed in front of the rocket body, so I assume they were all on one side of the rocket, likely originating some distance from it. This is confirmed by LabPadre's video from a different angle, an assymetric burst of particles. Combined with what you noted about the illumination of the particles, it seems we have a pretty strong case for something near the rocket being blown to bits and being swept up in the plume. Fly safe

[@mikedonovan9033]

Homeboy these are humans we're talking about here. When the time comes to push an asteroid out of earth's path, we'll just accidentally push it closer.

[@Vector_Ze]

Old man born and raised in the USA. I've almost always used millibars when talking about atmospheric pressure. PSI, for contained air such as in a tire.

[@MrGonzonator]

What do you get when you cross a crumbling space rock with a species that pokes it and treats it like an experiment!? I'll tell you what you get: YOU GET WHAT YOU DESERVE: A Scott Manley video!

[@Dolores5000]

High def cam looks great!!!! Super interesting and love!

[@StarshipFairing]

Starship goes zoom and boom on Bennu

[@xenotriver]

Rockets on profile pictures go brrr

[@nilsber.]

Wait that is the goal of the starship???

[@KC_FlightChief]

Honest to god if it weren’t for Ksp I wouldn’t understand any of how the close encounters would effect it’s orbit. Understanding that is amazing.

[@KnighteMinistriez]

Would it be possible for earth to capture an asteroid and lock it in permanent orbit around the earth, making it into a second moon? Could this happen with Bennu?

[@ZayAgka]

Theoretically it is possible, however that would be an awful idea

[@leafsfanforever2896]

There is a very small and precise area called a gravitational keyhole, which effectively sets up a future impact event. Such features were studied for Apophis

[@douginorlando6260]

Your Bennu cross section side view looks like 2 parabolic cups. This makes sense when combining centrifugal force with gravity.

[@honglianglim8637]

Scientists on Earth: **Pokes Bennu** Bennu: So you have chosen death

[@bryantaustin5186]

I love this video! It will be interesting to see how asteroid orbits are affected when mining begins.

[@rahuln5676]

Don't give 2020 anymore new ideas Scott.

[@miroslavmilan]

TIL asteroids have keyholes. Thanks Scott!

[@malahammer]

LOOK there are no stars in the sky and the Asteroid is flat!!!!! :)

[@BlockWorks]

When i see Bennu, i feel like i could punch a hole through it and all those little rocks would fly away, it looks so fragile, looks like a bird could do a shit ton of damage to it

[@Danger_mouse]

1:17 NASA & JAXA sharing the same image and adjusting the contrast 🤣👍

[@wierdalien1]

Nope

[@Danger_mouse]

@@wierdalien1 *Joke

[@nicosteffen364]

The kinetic energy may be the same, but there is a big difference on the impact if you throw a stone or the same mass of sand! I think at the moment when it hits the atmosphere it will fall apart and spread the energy over a wide area. The airflow takes stone after stone away, what hits the surface is way smaller than if it would be a compact asteroid.

[@dazzathecameraman]

"One point four gigatonnes.... Great Scott!"

[@Tailspin80]

Is that 1.21 gigawatts?

[@vidalroland]

If there is no internal strength, maybe we should look for probe giving it rotation instead of impacting it ... This solution can be more efficient for short term impacts

[@TehJumpingJawa]

Can't help noticing your background animation of the recent asteroid impacts on Earth seem to have a southern hemisphere bias. Is that just chance, observer bias (better detection?), or does the southern hemisphere actually receive more impacts?

[@CompoundNila]

That's Actually a really good question.

[@Richsalvageconsultan]

"Loaded up and Trucking . . ." (Heard about a gent in the tractor of a big rig, who reached down to engage his Jake brake lever when he spotted a 'Smokey Bear' bearing down on him, going the other way. Problem turned out to be, that he hit the switch that opened the doors holding in a whole bunch of little rocks. This "county mounty" was not best pleased, at what all of that gravel did to his Bubble Gum Machine, when the trucker's 'rubble pile' impacted his cruiser and nearly washed it off the roadway and into the ditch.)

[@XavierXonora]

The things we can do when we set aside differences are astonishing

[@Cyberdactyl]

At the equator, mass is probably close to zero-g because of rotation. Mass _(gravel and rocks)_ that 'slip down' from the poles may actually impart enough energy to send stuff near the equator into escape velocity. As well, once enough mass has accumulated at the equator, particles may actually reach centrifugal acceleration enough to break free.

[@NightRunner417]

Hey that's cool: I've watched this channel on and off for a long time but only just now noticed The Expanse books on the shelf. I'm a huge Expanse fan. :-)

[@DanielVerberne]

Fascinating stuff. I found the likening of Bennu's surface material to a children's ball pit to be intriguing.

[@ryuail]

How long has that Dragonriders of Pern book been there? How have I not noticed it until now?

[@meatybtz]

The problem with using rocky model for a dust ball/gravel ball is that the rocky body has some level of internal integrity so as it encounters the atmosphere it has to be heated, melted, or just ablated for material to be lost or integrity to be reduced such that it breaks up. While my brain won't let me recall the physical model used for modeling particle systems (not atomic but say, modeling motion of sand, gravel, etc), it has been extensively modeled and it's pretty obvious that a dust ball will quite literally splatter on the atmosphere as there is no integral resistances except the particles exerting pressure on each other and when a solid object is encountered (which is what the atmosphere is like at these speeds) it will instantly break up. Dynamically this is quite different than the Russian rocky meteor where it slowly transferred energy until reaching the critical point and then the remaining energy was transferred like unto an explosion, which caused the damage but that energy was the sum total minus all the energy lost during it's path up to that point, which was a lot. Even a large enough rocky body or a metallic body that reaches the ground still impacts with less energy than it had to begin with because of what was lost during entry, which is actually significant. If we calculate the energy released in the Russian rocky meteor at it's entry point and use that as though that was the energy transferred at breakup the damage would have been cataclysmic. Which is why my personal feelings are that dust balls are actually more dangerous because of the lack of incline to the energy transfer rate. It's just 100% (or nearly so, there is some penetration, but it is very small). Energy transfer rate is critical to understanding the dynamics of a system. A rocket burning it's fuel over time has a nice flat curve for energy transfer. That same amount of fuel igniting all at once is cataclysmic. For the less physics inclined it is the difference between taking your hand and balling up your fist minus a finger pointing down and punching into the water of a pool vs slapping your open palm with the same force on the water. The energy of the two systems is identical. However the rate of transfer of that energy is different.

[@ventusvero4484]

Scott Manley videos, be they "What if" knowledge bombs or Kerbal War Crimes against Jebediah, are truly timeless. Catch them in the first week they come out or months/years later, they are always worthily of your time and always age extremely well.

[@mikecronis]

Angle matters. Material matters. Odds are 29% it would hit land. 40% of that or less is populated in some way, so a 14% chance of hitting a populated area at-best. Size and debris will matter and likely cause a cooling of 10 deg. F. for a few years on-average though. All depends on a lot of factors as stratospheric dust would spread. Fun fact: the color of the "shooting star" tail tells what kind of material the asteroid or meteor is made of. Yellow is iron, orange is calcium, cyan is magnesium, depending on the chondrite material.

[@c016smith52]

The animation of an asteroid breaking up was super cool!

[@vclamp]

Given Bennu's gravity of 0.00009807 m/s² divided by Earth's gravity of 9.80665 m/s2 = .00001, and that Bennu is just a loose pile of rocks barely holding together, would it not begin falling apart due to gravitational sheer well before hitting the atmosphere? That would give the atmosphere a net greater resistance. Especially if the initial approach angle is shallow.

[@Dewolvez]

hey sir, this is a good topic since 2021 is coming.. you know, to put our hearts ready for every possible way..

[@javierlatorre480]

0:45 That first shot of OSIRIS-REx blasting Bennu with air is very reminiscent of depictions of asteroids hitting Earth and ejecting material into space.

[@kevinwhite9919]

i think we could probably also disperse it with even conventional explosives, enough so that the screed that hits the earth (again, with the same total kinetic energy) is so dispersed that perhaps all of it would burn in the atmosphere (there'd be little to no screening by an outer shell of debri). of course, we have a decent guess as to the internal density, but not complete certainty. in any event, simulations of different types of bombing of Bennu would be fun to see.

[@BOOGY110011]

At 0 °C and normal sea level pressure a mole of gas occupies 22.4 liters, so a cubic meter of air has a mass of: 1000/22.4 ×makes it 0.02896 = 1.293 kg." Google says

[@1TakoyakiStore]

I can't help but wonder if Bennu grazed our atmosphere if that would be enough to rip it apart in a somewhat similar manner to the Great Daylight Fireball of 1972?

[@Badspot]

There's a video floating around of a large bucket excavator dumping a load of water onto a car and crushing it. Might illustrate the problem a bit.

[@gwarner99b]

I was reminded of people who claimed that birdshot from a shotgun was harmless. Not at close quarters, it isn't. I also thought about the reason nuclear war strategists move to MIRV, multiple warheads that spread out, rather than single high yield bombs. The latter waste energy blowing up the same area many times over, while the former MIRVs distribute the same explosive energy more devastatingly over a wider circle. I wondered from the start if there would be enough time for the Bennu rubble to spread out between entering the atmosphere and hitting ground?

[@LongPeter]

I love that you did the maths for everything down to the size of the crater produced and how many meters of orbit change would result a hundred years after the cosmic raspberry-blowing interaction.

[@UncleManuel]

The most filmed meteor did hit earth already 7 years ago? Wow, time flies...😳

[@Quickshot0]

The material being this loose also brings up the question on if you could some how exert enough force on it to gravitationally scatter the object. If you scatter it early enough, most of the object would never hit the Earth... but admittedly this would also mean you couldn't mine it later, so I guess there is a trade off there, and its orbital area would be filled with a lot more debris after that as well, which might not be that great either.

[@yuvi6034]

Waiting for your video on explaining fully stacked SN8 static fire

[@ambientoccluser]

Also, I think, it'll melt under friction into a more crusty sort of ablative shield that might endure most of the bennu onto surface .

[@beijingbond]

I'm no scientist but when we knew that piece of foam hit the Shuttle I knew that that was the cause of the damage. "But it's only a piece of foam!", they said. "Ahh, but at supersonic speeds ?", I replied.

[@АбракадабраКобра259]

While we sure can affect known things like Bennu, chelyabinsk meteor wasn't known of until it actually exploded over there. And the thing wasn't big by any means, just damn fast. And thanks for the angle it hit the atmosphere with it didn't make it all the way to the ground.

[@smashOsmash]

The image of the asteroid gave me a thought. To not able to explain something, doesn't make it weird . You can know something without understanding it . You can understand something without knowing how to explain it . Weird is when you don't know something, not when you don't understand something . And sometimes somethings can be understood and explained, but not known . Therefore making it weird . Waves for example, throughout history people didn't truly understand how they were formed, but I don't think they were weirded out by them, because they knew what they are, but they didn't understand it. And some people notice that birds migrate before storms, so they understood that but they can't explain it. And for me space and asteroids and planets are things that can be explained and understood, but for me they are unknown, therefore they are weird for me. For thousands of years humans first notice how the nature works itself sometimes they could understand it and sometimes they can't understand it but for thousands of years they knew what nature is, it was never weird for them. But now we skip the step where we just live with space the same way we lived with nature and just jump to conclusions and explanations and understanding, even if we are successful in understanding space, I think it would take us many more years for us to know space and live with it, without feeling weirded out about. (English isn't my first language so excuse any mistakes, and if you read all of that, thanks for hearing me out! :) its the first time i write something like this on a youtube comment section)

[@TheNormalUniverse]

Scott manley you're a treasure!