Guest essay by Eric Worrall
Following recent concerns that the risk of dangerous Asteroid impacts may have been underestimated, NASA appears to be stepping up its plans to develop the capability to deflect inbound space rocks.
NASA DART MISSION LAUNCHES TO SEE IF IT CAN SHUNT AN ASTEROID AND SAVE US FROM ARMAGEDDON
Nasa has successfully launched its Dart mission, which aims to crash into an asteroid and see whether it could save us from destruction.
The robot spacecraft launched as planned on a SpaceX Falcon 9 rocket at 10.20pm local pacific time from Vandenberg Air Force Base on the California coast, about 150 miles northwest of Los Angeles.
The Dart mission will test Nasa’s ability to alter an asteroid’s trajectory with kinetic force – crashing a robot spacecraft into it at high speed and nudging the space boulder just enough to keep our planet out of harm’s way.
…
Dart’s target is an asteroid “moonlet” the size of a football stadium that orbits a much larger chunk of rock – about five times bigger – in a binary asteroid system named Didymos, the Greek word for twin.
The moonlet, called Dimorphos, is one of the smallest astronomical objects to receive a permanent name. But at 525 feet (160 km) in diameter, its size is typical among the known asteroids – rubble-like remnants left over from formation of the solar system 4.6 billion years ago.
Scientists chose the Didymos system because its relative proximity to Earth and dual-asteroid configuration make it ideal to observe the results of the impact.
…
Read more: https://www.independent.co.uk/life-style/gadgets-and-tech/nasa-dart-asteroid-launch-mission-b1963314.html
I’m glad someone is finally taking this problem seriously. City buster impactors or worse are extremely unlikely on human timescales, even if scientists are still discussing exactly where to put the decimal point. But unlikely is not zero risk – its worth a few million to ensure we have the capability to address such a threat if it arises.
Over at the Cosmic Tusk are mentioned 2 new movies, Greenland and Don’t Look up, both about incoming objects. Only Greenland actually shows the real threat – a comet tail of rubble like the Taurid Stream 1 and 2.
We got hit by such a tail in the Holocene.
The difference between a cannon ball and a shotgun, all at hypervelocity.
Airbursts of such debris – witness Chelyabinsk, Tunguska, are well studied.
What NASA has planned for that I do not know – but it will have to involve nukes.
Nice graphic here :
https://phys.org/news/2021-11-nasa-spacecraft-asteroid.html
We pass through comet tails every time we have a meteor shower. Comet tails just have gas and dust, few if any big rocks.
Tell that to the inhabitants of Al Hammam and Jericho :
https://cosmictusk.com/tall-el-hammam-impact-jordan-valley-sodom/
The Bible got it right!
The Bible said a comet impact destroyed two cities?
2 new videos at :
https://cosmictusk.com/taurid-meteors-past-and-future-threat-to-life/
DART will take a year to reach target. Nuclear rockets are needed to hit them with less warning, not just explosives.
And the amount of money currently being spent to develop nuclear rockets is . . .?
Right – just imagine the mad rush in a real situation.
Right – which mad rush will be far too late to meet the need.
How much was being spent when JFK made his 10 year plan?
Lesson :
Mars in 3 weeks with engines running all the time not just for 6 minutes means no mad rush in an emergency. Mars means 1g acceleration then 1g braking. A comet means 10g, no braking and major kinetic impact, a precursor shock, then fuse that.
A whole different ball game!
Sometimes, development of new technology just takes time . . . it’s commonly referred to “coming up the learning curve” . . . and no amount of money beyond a critical amount can significantly accelerate the time span needed.
If nuclear rockets could be developed so quickly (say in less than 10 years) and yield the results that you envision in your post, why hasn’t NASA done this already?
Moreover, why didn’t NASA devote the funds spent on the DART Program to this critical development?
The basic reason is that every time anyone mentions NASA or the DoD launching anything nuclear into space, the anti-nuclear crowd goes into high-gear, picketing launch sites and descending on Congress. Now, the Government has launched nuclear powerpacks on satellites, but a nuclear-powered space craft is just politically unpalatable, just as as nuclear power on the grid.
I seem to recall a geat deal of flack from certain quarters about deploying well developed “nuclear” battery technology in long distance space missions.
Nuke batteries already work on Mars. Not the same as a fusion engine.
bonbon,
There is really no such thing as a nuclear battery.
I do believe you are referring to a radioisotope thermoelectric generator (RTG). RTGs provide electrical power using heat from the natural radioactive decay of plutonium-238, in the form of plutonium dioxide. The large difference in temperature between this hot fuel and the cold environment of space is applied across special solid-state metallic junctions called thermocouples, which generates an electrical current using no moving parts.
RTG’s cannot accept and store electrical energy from an external source (i.e. be “recharged”). Also, the source of power generation, heat from radioactive decay, gets depleted at the half-life of Pu-238 independent of the amount of electricity demanded from the RTG.
All of these processes are quite different from what occurs in a typical electrochemical-based battery.
Have you any idea what happened on 22/11/63 ? Declassify now as Trump said, with Biden delaying 1 year.
If it’s classified, how is that you know what happened?
FBI facilitated assassination under direction of CIA (FBI does CIA’s domestic dirty work; see: Russian Collusion Hoax).
Assuming you mean the date more commonly expressed as 11/22/1963 (i.e, November 22, 1963), are you referring to the day living aliens from a crashed spacecraft were taken to Area 51 and forced to help the US develop faster-than-light propulsion and inertia cancellation field technology?
Or did something more important than that happen on that particular date?
You forgot the part about how the FBI assassinated the poor undocumented space immigrants. At least that seems to be what bonbon had in mind.
Like the sudden turn toward nuclear power stations in the UK, due to rising gas prices?
Ion engines already exist and provide everything nuclear engines are supposed to.
MarkW,
Not quite . . . compare the maximum thrust of current ion engines to that needed from nuclear rocket engines to travel quickly within the solar system . . . there are 4 to 5 orders of magnitude difference, the current ion engines being the lower thrust level of the two.
Ion engines are used for long term (days, weeks, months) continuous but very small thrust. Think station keeping in orbit, or accelerating small payloads. Nuclear engines would be much higher thrust (as Gordon mentions), therefore suitable for much larger payloads. I suppose ion engines could be scaled up, but they would still be much lower thrust, afaik.
1) We will generally have well over a year warning against large impactors. Small ones, not so much, but they are not as dangerous.
2) Not sure what you’re saying about explosives. This impactor is supposed to shift the orbit of its target, not blow it up. You’d take a huge amount of nukes to break up a dangerous impactor (Bruce Willis notwithstanding).
Blowing it up could change a Chicxulub to 1,000 Tunguskas, which do you prefer?
Any chance this will backfire, a little at least?> No chance one asteroid will hit another, then more collisions, then what? What’s that condition we are worried about with space debris hitting satellites in Earth orbit? Maybe we should first test this on the “hologram deck”./
If I recall correctly, one issue is whether asteroids have enough structural integrity to hold together after an impact.
I think those concerns have been amplified after the recent sampling missions. There appear to be some large individual rocks in asteroids, but not a lot of structure.
A lot depends on the history of the asteroid. If the asteroid formed by smaller rocks collecting together, they will just be a rubble pile. Other asteroids formed when larger objects got smashed into smaller pieces. If the original larger object was large enough that the energy of it’s formation was enough to start melting the rocks, then the asteroid is going to be solid.
There are theories as to how many asteroids fall into either category, but until we can get up close and personal with a lot of asteroids, it’s still just a guess.
diverted from original, no real danger trajectory, to raining down on you head.
NASA may have its failings (the Senate Launch System comes to mind), but it is better at playing billiards than that.
“If I recall correctly, one issue is whether asteroids have enough structural integrity to hold together after an impact.”
We might have to use a gravitational tug technique on rubble piles.
The gravitational tug flies near the asteriod and stays there permanently, and its small gravitational pull will eventually change the orbit of the asteriod.
This would not be a short-term fix, it would take time to change the orbit, so NASA needs to get their asteriod spotting up to speed, so we can spot problematic asteriods in time to do something about them.
As I recall, their calculations showed that an ion engine, for example, could change the asteroid’s path more than a collision, but of course would take more time and need more planning. How realistic any of these plans are is a different matter.
It’s likely a hail Mary situation, with fancy solutions having too many failure modes….depending on size….if its a rock pile, just blow it to bits, 95% of the bits will no longer be on an impact trajectory with the Earth….you could send a succession of missiles that blow up any larger bits still on the original trajectory……if its a solid iron body, wait till its in the right rotational position and try to blow it in as close to two debris clouds as possible, with the debris passing Earth on either side. A couple of Tsar bombas might do it if you can hit it far enough out….but a really big iron body on impact path with Earth is not going to be a survivable situation. We don’t have enough enriched uranium….
But what effect does global warming have on asteroid strikes?
Obviously driving SUVs attracts asteroids
Obviously, more CO2 in the atmosphere makes the atmosphere thicker. That should provide more protection from asteroids. <insert smiley face>
No no no! More atmosphere means more captures. It’s worse than we thought. 😉
It’s all caused by Elon Musks red Tesla orbiting out there.
A far likelier reason why aliens might seek to destroy humanity…
Sa,e effect it has on solar output, I believe.
Hopefully there is success in this mission. If thr kinetic approach fails will the try to destroy on , or possibly land some form of rocket booster
The problem with rocket booster is that if the asteroid is just a rubble pile, a rocket booster runs the risk of just punching through the pile when it is turned on.
I think the surest way to handle an asteroid you haven’t had time to study is what they call a gravity tug. Place an object near enough to the asteroid that gravity starts to pull the two objects together. Have a rocket motor on the object so that you can keep the object at a set distance from the target asteroid. Then let gravity pull the asteroid into a safe orbit. Since gravity affects all parts of the asteroid more or less equally, you don’t have to worry about rubble piles being pulled apart.
I thought that one advantage of the tug as opposed to a push was better control of the direction. A pusher would have to land, and then continually re-orient itself even if the rubble pile stayed together.
Another problem with pushers is that most asteroids are rotating.
another problem is the huge mass difference between an earth made rocket boaster, or atomic bomb, and an rock big enough to be a real threat.
A nuke can shatter a rock that is a few hundred feet in diameter. A rock that size can easily destroy a city.
If you hit the rock far enough before impact, even a few mm/sec can easily be enough of a velocity change.
The problem with a lander or gravity tug is one of orbital mechanics. DART is not a fast-moving object impacting an asteroid. It’s a slow-moving object maneuvering into the path of a high-speed asteroid. It arrives at Didymos at the apogee of its Hohmann transfer orbit, the slowest point in that orbit. A huge delta-V would be required to catch up and land.
There we have an innocent little asteroid going about its celestial business, innocently staying in its own orbit, when along comes a psycho who knocks him(OK-her) over and accidentally changes his/her orbit. Next thing we know, it won’t be a climate emergency but a deep impact one. 🙂
Worse still, we change its course enough that in a few million years it hits some other planet, who’s life forms get all perturbed, and a few million years later, develop FTL drive, and invade our planet.
But, due to a horrible miscalculation of scale, their entire battle fleet is swallowed by a small dog. (h/t Douglas Adams)
Worse still, we change its course enough that in a few million years it hits some other planet, who’s life forms get all perturbed, and a few million years later, develop FTL drive, and invade our planet.
It wasn’t the bugs fault in Starship Troopers after all!
Sounds like a mission to cause unintended consequences… Like causing Dimorphos to orbit elsewhere and likely collide with a planet.
The DART mission impactor is far too small to significantly change the dual asteroid system’s orbit around the Sun. This moonlet was chosen because the small expected change of momentum could be very precisely measured by seeing how its orbit around Didymos is altered. That is a very subtle effect that can be monitored much more easily than trying to see the effects of a tiny change in velocity around the Sun.
Good points.
This moonlet was chosen because the small expected change of momentum could be very precisely measured by seeing how its orbit around Didymos is altered.
Yes, the mission design is really quite nifty. They’ll have a 1,200 pound spacecraft impact a 525 foot diameter asteroid at 6.7 km/sec closing velocity. Even a porous clay object that size would have a mass of ~5E6 tonnes. An inelastic collision between two bodies of those masses would result in slowing down the larger one by 7.4E-4 m/sec. The orbital period of Dimorphos around Didymos is currently 11 hours 55 minutes. NASA will consider the experiment a success if they can change the orbital period by 73 seconds. The effect on the trajectory of the Didymos/Dimorphos system will be insignificant.
Blowing an asteroid into pieces (or blowing a significant chunk off) soon enough before it would hit Earth would not produce a shotgun of collisions, but cause a clear miss of most if not all of the pieces. Any explosion that removes even one large chunk or many smaller pieces that constitute a significant fraction of the mass of the asteroid would cause either a slowing or speeding up from the previous trajectory or cause a lateral velocity of the pieces, including the main body, of from a fraction to several meters per sec. Any change would cause the segments to arrive too soon, too late or miss to the side if enough time remained before collision. As an example a change of 1 meter/sec in any direction over 1 year time moves the object 31,500 km (19,600 miles) from the previous trajectory location and easily misses Earth. Remember Earth is moving also and orbits cross only at 1 point and one time.
I want to point out that this only works if the time to collision is large enough. You can’t do any good in the few days or even weeks before collision. You need months unless the object is small enough to blow all od it in small pieces with very high velocities away from the initial trajectory.
Assuming the asteroid is close enough that most of the fragments still hit the earth.
I would think having a few hundred air bursts scattered all over one side of the planet would be preferable to having one city killing sized crater,
1) If the asteroid is that close, we would have a general idea where on the planet it was going to strike.
2) If the asteroid lands in the oceans, it would cause a massive tsunami that would wipe out anything that lives within a few miles of the coast.
3) Even if only 10% of the asteroids mass missed the earth and the speed of the asteroid was reduced by a few percent, the total energy striking the earth is still reduced.
“a few hundred air bursts scattered all over one side of the planet would be preferable to having one city killing sized crater”: I think you’re largely right, but I was in a discussion in another forum with someone who pointed out that the amount of kinetic energy from an impactor–most of which would be converted into heat–is the same regardless of whether it hits in one piece or many. The claim was that the asteroid that killed off the dinosaurs did so as much by heating the atmosphere (for a brief time–maybe a few days) as by the ground impact itself. I’m not entirely sure how to evaluate the relative impacts (pun) of those two aspects of the event, but it seems plausible that the heating from a large impactor would be dangerous. (And no, this is NOT about climate change, so hold your comments on that.)
Depending on the distance even small impacts are enough to change the direction so it misses the target,
therefore i absolutely do not understand why it should be blown into pieces?
A simple shockwave should be enough to get the wanted effect.
The object keeps its integrity and keeps its observable size. Blowing up into 1000 pieces can reduce its quality but increase the quantity of objects.
I beieve Leonard is presuming that the asteroid is too close for a gentle nudge to be sufficient.
If thats the case than I’m ok with his argument as thats the only remaining option .
Correct. Also a small nudge on a very large object may not be enough even over many years. It depends on details. Most NEO’s have calculable orbits to high accuracy, so many years may be available. Objects knocked in from far out are only determined at most a few years or less before impact, so more extreme deflection is needed.
Shatter and scatter. One bunker buster nuke to break up the rubble pile followed up by a second in the debris field to increase dispersion.
Quote:“NASA appears to be stepping up its plans to develop the capability to deflect inbound space rocks”
Methinks an ‘inbound squirrel‘ deflection system would be much more useful
maybe its coz they’re all nuts at NASA, is that what’s attracting so many recently?
Be wary of squirrels – the can carry the Pest!
I’m sorry, what scale are we using here?
525′ is 160m not 160km
This is cool, if it works. I am curious to see the results.
About bloody time we tested these ideas.
I like the chosen image for the article. I generally am only thinking about the ejecta when the topic of an asteroid strike comes up.
This image shows a big ol’ shock wave propagating through the Earth. That isn’t discussed much. Mostly the effects on the atmosphere are considered.
But a massive shock wave would sure cause a lot of wiggling and jiggling in faults and unstable mountainsides, let alone the bulge in the Earth opposite of the strike.
👍 👍 Good image choice.
Funny, I look at it and see a big cannon shooting an enormous projectile from the Earth out into space (a la Jules Verne). All part of homo sapiens’ attack on the Universe…
Let’s see . . . how many tens of $millions will that be for a simple demonstration of the law of conservation of momentum for two bodies experiencing an inelastic collision in space?
Oh, yeah, right, there probably will be a little bit of propulsive energy obtained from the volatiles generated at the impact site. However, since (a) those gases would be emitted hemispherically (not going through a rocket nozzle) directly into the vacuum of space, and (b) since it takes relatively large amounts of kinetic energy to create significant increases in sensible temperature, maybe we’ll learn that we get an additional 2-3% of effective propulsion at the impact site.
Of course, any net propulsive effect will be less if the asteroid is spinning with respect to the spacecraft at the time of impact . . . as a matter of fact, unless the impact vector passes very close to the asteroid’s center of mass, a significant portion of the spacecraft’s impact momentum will be transformed into rotational momentum, not translational momentum. Increasing/decreasing any asteroid’s rotational momentum will not act to “deflect” the asteroid from its pre-impact orbital path.
Lastly, we’ll obtain the impact’s orbital-change information for a single class (composition) of asteroid for a single impact-vector-versus-asteroid-center-of-mass condition . . . how many other classes of asteroids might be on a future collision course with Earth?
I’m not saying that the science behind this program is not interesting, but I am questioning it’s raison d’être versus cost.
NASA has the luxury to wait 1 year for the impact test.
A real threat would quickly escalate to DEFCON1, dusting off a few 100Mt thermonuclear bombs. I am sure SpaceX would have no trouble launching, no matter what space-greenies would say.
The problem is the travel time. Musk cannot deliver right now. We need nuclear engines that run for weeks hitting quite high speed. One could even use kinetic impact as well.
Another problem here is the misconception that nuclear fission or fusion bombs create a lot of blast force in space conditions.
In reality, most of the energy release from supercritical fission or fusion reactions appears in the form of radiation across the X-ray to gamma-ray spectrum. Without a surrounding atmosphere, a nuclear detonation in space will heat up surrounding things a bit, but not cause any blast effect.
Then vaporize the rubble heap itself – use kinetic impact then fuse.
Take the temperature later.
. . . and exactly how many 100 Mt thermonuclear bombs have you calculated will be required to vaporize just one small asteroid the size of, say, Dimorphos (525 ft across), the target of the Dart mission?
Don’t need to vaporize the whole thing. The vaporized rock leaving the surface will push the asteroid in the opposite direction, deflecting it.
also, nobody has any 100 Mt nukes. 1 Mt is launchable and would suffice.
Ever heard of Dial-a-Yield?
As Sakharov said about Czara Bomba, there is no limit, and Russia dialed back 30% from 150 megatons. Ivy Mike got the lithium wrong and look what happened….
What do you think NIF is actualy testing – not power…
I flew B-52’s for six years and have been through nuclear weapons school. I am very familiar with dial-a-yield, having rubbed them on the nose and looked in the little window to make sure it said the green S and not the red A.
B-52’s have served our nation well.
Still serving after all these years. It’s pretty amazing.
How about a large billboard on the dark side of the moon :
WARNING – YOU ARE ENTERING AN ASTEROID FREE ZONE!
They put those about guns and drugs around schools and it works, right?
?
We need to take the feelings of the asteroid into account. I propose these measures.
1) We don’t call them “Asteroids” any more. That has such a negative connotation. From now on we should call them “Heavenly Bodies With Roids”.
2) I propose a vigorous, and I do mean vigorous, leaflet campaign (h/t Arnold Rimmer). This would encourage the Heavenly Body With Roids to choose another path in life, something more meaningful and fulfilling, like slamming into that bastard Jupiter instead.
Let us call the real 100 Megaton thermonuclear ‘Roid-buster warhead Woke 1.
That should pass even a Senate Hearing.
‘Roid-buster is an unfortunate phrase.
Deplorable!
Hey, it’s not like we haven’t previously done something similar to this.
Beginning with the Apollo 13 mission in 1970, a total of five S-IVBs were sent to impact the lunar surface (see https://www.space.com/31503-apollo-16-moon-rocket-crash-site-photo.html ). The S-IVB was the third stage of the Saturn V rocket that eventually landed a total of 12 astronauts on the Moon.
Obviously, we knew the orbit of the moon (more specifically, its orbital ephemeris) very precisely even before the Apollo program. We know the Moon’s current orbital ephemeris very precisely.
You mean to tell me that, as of today, nobody can mine this data to establish how effective a vehicle impacting a body in space can be with respect to altering its orbit?
Or maybe it’s just too much fun to launch new missions, rather than do “boring” data analysis? 🙂
That was the almost forgotten era of space travel. Obama killed Constellation, and now Biden delayed Artemis (or NASA). Trump was right.
Let us see if if DART still functions after 1 year in deep space…
That’s what I was thinking. Isn’t data analysis and computer simulations good enough like for stockpile stewardship?
I hope they are correct.
May as well try to calculate how much a mosquito getting rammed by a vehicle windshield affects the speed of the vehicle.
No, as Michael S. Kelly posted above in response to a post from ATheoK, it is the precise measurement of the shift in the orbital period (not the direct measurement of the delta-V imparted at time of impact) that allows the very precise calculation of the impactor’s “deflection” effect.
Hitchhiker’s Guide – Earth Destroyed and Guide Introduction (HD) 4min
https://www.youtube.com/watch?v=Z1Ba4BbH0oY
Even worse than the announcement is the Vogon Captain’s poetry recitation!
Interesting side note. The DART mission was going to be combined with other payloads to save costs until SpaceX gave NASA a price launching it with Falcon 9 as a standalone payload that was cheaper. By reusing boosters (128 launches with 70 reflown) and launching large numbers of missions annually, SpaceX has really gotten the costs down.
The legacy rocket builders like Boeing are still in existence only due the US government and their continuing inability to get Starliner to the pad may be the final nail in the coffin. In the meantime there are startups planning to use 3D printed rockets, air launches and even a giant centrifugal sling to launch smaller payloads. Goes to show the benefit of individual effort over bureaucratic organizations.
NASA did all that and more , with 440,000 staff.
Next step Mars in 3 weeks – no private firm will take that risk. Let them later get costs down, first let us get serious new engines running.
Ummm . . . did you mean to say 3D printed select parts for rockets?
I have yet to see a 3D-printed hydraulic actuator assembly (it’s hard to print elastomeric o-ring seals and parts that move inside other parts), nor a 3D-printed ball bearing assembly.
3D-printed whole rockets? . . . Pffthptffff!
Right, and the turbine 5-axis machined impellers at LOX temps. No chance.
No really, 3D printed and they use artificial intelligence and they’re web-based with blockchain technology and 18 other overhyped pseudoscientific marketing concepts!
“The legacy rocket builders like Boeing are still in existence only due the US government and their continuing inability to get Starliner to the pad may be the final nail in the coffin.”
I think that’s right. The industry is evolving. For the better, because it is evolving away from bureaucracy.
” . . . may be the final nail in the coffin.”
NASA in the 1960’s responded to JFK’s call in May 1961 of “before this decade is out, of landing a man on the moon and returning him safely to the earth” . . . a program successfully completed in period of just a little over 8 years!
NASA contracts with Boeing for the Starliner launch system and crewed capsule with an initial “kickoff” contract of $18 million in 2010 then subsequently, in 2014, the major contract of $4.2 billion. So, now going into 8-12 years later, the Starliner has yet to have even a successful test flight!
I believe the “final nail” in NASA’s coffin, with respect to managing manned launch and spacecraft systems, was firmly hammered in more than a decade ago.
h/t Cosmic Tusk : Petrov on Comet Enke :
Breakup of a Giant Comet 20000 Years Ago Linked to Tunguska Event and 88 Asteroids
Well, I don’t know how to embed Youtube, so here it is as a link. Breakin’ up is hard to do.
https://youtu.be/tbad22CKlB4
My link worked – seems MODS had to do something, or the Service…
Dunno. I tried both the embed link and the URL.
I am worried – are those asteroids a part of environment?
Is such deflection any good for environment?
Why are you deflecting the topic of the article?
Because asteroids, like “climate change”, are a more immediate threat than the Chinese military. 🤪
Typo in the article. 525ft =0.16km not 160 kms
This seems pointless. Knowing the mass and velocities of both the asteroid and the impactor, the change in velocity of the asteroid is almost precisely known without the test. This impactor is probably too small to eject much material or break up the asteroid. So what are they hoping to learn from this?
Whether they can alter the orbit of the asteroid.
One interesting known unknown will be where on the spectrum of elastic vs inelastic collision will result upon impact. If DART simply impacts and is buried with no ejecta, you’d be inelastic. If there is a lot of ejecta, possibly enhanced by vaporization of volatiles, the results could nudge things a little toward what one would expect from an elastic collision. I suspect the researchers do not know exactly what will happen, which is one reason why this is an interesting and potentially very useful experiment.
Consensus scientia neglecta est.
Theoretically, if you insert a nudge mass like a rocket into the asteroid system, all asteroids will feel some gravity change and will all move to seek a new equilibrium. Can we foresee huge computer simulations of real time readjustments to keep us informed of the latest asteroid with a threatening path? Yes, I know this force perturbation is tiny, I am being theoretical. You do that when you have no apparatus with which to be practical. Geoff S
All asteriods change their orbits over time. The Sun’s radiation has an effect on their orbits.
Id like to see the physics
mV = mV(space craft) + mV(asteroid)
as the space craft weighs kg and is travelling at very high speed and asteroid weighs billions of tonnes travelling at moderate speed
I expect like Bruce Willis etal found out
no difference
But hey these folks at NASA have change the conversation at least for a nanobyte
Here some physics:
NASA DART website – https://www.nasa.gov/planetarydefense/dart
Some calculation required, not all numbers on website.
Orbital speed of moonlet (the term from NASA) V=0.17 m/s
Mass of moonlet (I assume that densities are equals) M=4.56e+9 kg
Momentum of moonlet P=MV=7.87e+8
Satellite mass m=500 kg
Satellite speed v=6.6 km/s
Satellite momentum p=3.3e+6
If you are using above data, then the result of impact will be exactly like on NASA website – the change of orbital period around 9 minutes. But satellite should kick that small “moonlet” exactly from front or from behind in order to maximize momentum changes.
Ratio of satellite momentum to moonlet momentum k=4.19e-3.
The experiment obviously is not about direct deflection of asteroids.
Probably the structure of asteroid’s body, most likely just a matter of getting funds.
The real collision of asteroid with Earth could be at speed of about 17 km/s, which is four order of magnitudes bigger compare to DART experiment. The momentum ratio would be around 4e-7 and no deflection is possible.
If scientists and government officials identified an imminent threat would they tell the public?
Or would they initiate a DART mission without revealing the threat?
They would seek to minimize panic.
Joe Rogan did a few podcasts with Randall Carlson and Graham Hancock discussing this issue. Perhaps a few NASA-ites finally went over to YouTube to watch them and got a little concerned about the potential seriousness of this issue and particular problems of many of the potential solutions. They also discussed how little we were spending to address the problem.
How about deflecting them into orbit around the Moon, if they contain metals, parking them for mining? Or send them off to Mars to give Phobos and Deimos some friends.
There’s a big difference between changing the orbital trajectory of an asteriod a small amount verses capturing the asteriod into a lunar orbit.
How about we take care of the asteroid problem the classic way? https://www.youtube.com/watch?v=WYSupJ5r2zo