Is it? Isn’t it the case that we can’t even detect the vast majority of objects on a potentially problematic intersection path with earth? I feel like the most likely scenario is that by the time we realize we’re about to get slammed by an asteroid, it’s way too late.
The point of DART mission wasn’t that we can deflect every asteroid tomorrow. It was to prove that physics and guidance actually work in space. Now the playbook is clearer: detect earlier, then nudge early.
If you get even a few years of warning, a tiny velocity change compounds into a huge miss distance. That’s the real takeaway.
Before this, even if we spotted one, we didn’t know if we could prevent impact.
Detection honestly feels like an easier problem, especially as networked sensors and space-lift capacity has improved.
I've been waiting for this a long time. They initially reported significant changes to the orbit of the smaller rock around the larger one which was cool and all, but I kept wanting to hear how much it affected the whole system. I suspect it's taken several years to answer that because it's such a tiny change in velocity. Dimorphos we can deflect, Didymos not so much.
And the “three-body problem” is overblown in pop culture: even n-body problems are fairly predictable in the short-ish term, it's just that you cannot predict things over a long period because measurement imprecisions have a snowball effect, but it's not particularly unintuitive (I'd say it's more intuitive than the idea that we could predict things with perfect precision over billions of years).
It's also the best planetary terrorism, going by the plot of The Expanse
By this point UN and MCR have been in cold war for 100+ years staring each other down with region killer nuke arsenals and an absurd amount of interceptors always ready. See than one time Mars actually fired a barrage - only like two warheads got through, only due to shitload of decoys and overall numbers.
A dumb rock would totally get vaporized without the plot armor in a safe distance.
That is simply "Assured Destruction" with absolutely no mutual drawbacks or lingering consequences like radioactive wasteland. Just craters.
This is also something where the 1st country to achieve the "Space Battleship" could effectively prevent any other from also doing so...
In theory, Bezos or Musk could do it.
I don't understand why any country would bother with ground based military assets at this point.
Nuclear countries would simply declare that they will launch nukes if any rod comes down on their territory. Even if you had thousands of projectiles in orbit (at considerable cost per projectile) this would not be significantly different from 60s-style MAD: put nukes in bunkers, in the air and in the sea to ensure they can't all be taken out. We might see the return of strategic bombers that stays in the air for weeks at a time.
Alternatively they can just shoot down your battleship with anti-satellite weapons. The risk of retaliation might be worth preventing the disadvantaged position in the long term
Plus - if countries don't do space wars - this will still happen 100%. It will just be a non-state actor - who do you nuke if Austin Powers is the bad guy from space?
Also, there seems to be a prevailing sense of "we'll just shoot it down" and that is actually extraordinarily unlikely - bc of all the space, in space. I wouldn't sit in orbit with my Space Battleship - maybe a lunar orbit.
Let's say I park halfway to the moon - ALL of my missiles will still hit earth, I don't think current defense systems would have any better odds - whats the difference between an ICBM that enters the atmosphere from space - shot from a silo or a spaceship?? Not much, functionally identical to the Space Battleship... missiles from earth tho, will be like in slow motion, the space battleship ought to be able to literally shoot them down with bullets - none will be able to surprise the space battleship, how do you even do a missle defense overwhelm tactic in such a situation - I can move the spaceship you know.
I may sound like I'm being unserious, but in reality, this is absolutely the future of warfare 100% - I can't be more serious, the humor is bc this topic makes me legitimately nervous.
And yeah, it is perhaps the most extremely imbalanced strategic advantage that can be attained.
But dropping rods from an orbiting platform makes no sense. There's a reason that "Rods from God" didn't pan out, and it has to do with orbital dynamics. Neither Bezos nor Musk can do it, because it actually doesn't work.
Earth is spinning in a giant circle around the sun. Thats facts. "aiming an asteroid" is less of making a rock a missile - and a lot more of tug-boating it into the exact right spot, in the way of earth, so that earth hits the asteroid - not anything complicated like the asteroid hitting earth.
There are a lot of little things like that...
You will need to replenish from somewhere & that somewhere might as well get nuked instead of the ship, rendering it useless.
I mean, you did say:
> space battleship - one that never comes down to the surface, just sits in orbit.
So I think it's understandable for people to take that at face value.
Furthermore, if it isn't in orbit, then where would it be?
> and a lot more of tug-boating it into the exact right spot, in the way of earth, so that earth hits the asteroid - not anything complicated like the asteroid hitting earth.
From an orbital mechanics standpoint I don't think there's actually a difference. You're changing an orbit either way.
What if I make that the space battleship's job? What if a drone can do that?
Im not really worried about resupplying the space battleship holding earth hostage -> someone will "volunteer" to do that, bc they want to live life.
Can you say more on this? Thanks!
I remember it was nicknamed "Rods From God". Kinetic energy weapon using 9 ton tungsten rods dropped from an orbiting platform. https://en.wikipedia.org/wiki/Kinetic_bombardment
There are ways to battle that - balistic missile submarines for one and then "Project Michael" which would be a massive spoiler to elaborate on. ;-)
How heavy would a telephone pole sized tungsten rod be?
What happens when China, Russia, India or Pakistan find out you are building this (cause you can't hide it if it's in near earth orbit)? They would either knock it out of the sky or hit you with everything they have. We would do the exact same if anyone else was developing such a weapon.
All required innovations - of which, most are not out of reach in the slightest, all of that tech would be immensely valuable, literally everything we do to secure space superiority will be actual gains - not smaller microchips equivalent innovations - entirely new machines, entirely new economies of scale - there is no equivalent military tech that we can develop on earth.
Not only is there really no conceivable way to ignore the strategic advantage once considered, the long-term economic payoff is actually reason enough alone to pursue the radical idea of a "space battleship" - I can think of about 20 ways to cause significant global issues with one measly space battleship.
As a hypothetical alone, it has reason enough to warrant a substantial amount of the 1.5 trillion defense budget the Pentagon plays with.
We feel safe here on earth but it's really a giant graveyard trap - that so effectively exerts control over life on it, that it made all living mammals out of mice - we may actually be safer on almost any other planet.
All life on earth has eventually died out so far, we are the 1st species that could stop the most likely extinction level event - but this DART is the closest we ever got to actually taking up that responsibility - the preservation of our species and whatnot, thats just 1 minor reason.
The most important tho, given how much we have example of people "getting theirs" at all other peoples expense - this is much worse if a non-state actor gets there 1st.
Lastly, I do have to clarify the American position - we run the world, or there will not be one to run. Nobody alive today made that decision - it changes nothing, once that choice was made, we are locked into it. Did you think we are only an economic power? That is the front. We can always pivot to actual power - the kind that can destroy all cities above a certain size - we have never hid this fact, the whole world knows of MAD. That is what power is.
What is American power if someone can destroy the US and we can't destroy them?? That doesn't work for the US - nothing at all changes if the US gets that spaceship first.
You can call this ugly - there were more modern wars before we started running things, from the looks of things - the whole world will go to war the moment we are out of the picture.
Before?! We're already doing a great job at it!
I was talking about the sun shaking in its orbit because high velocity objects are now pulling at it differently causing other objects to be influenced by the new position of the sun.
I read the parent comment as “solar orbit change” meaning the sub was changing position.
Or in other words, 1 meter per day
Why not say that?
I found the meter per day conversion helpful. Through another lens, it's about 0.000036 km/hour (or about 1.5 inches per hour).
Obviously there was the kinetic energy transfer but the impact ejacted some of the asteroids mass opposite to it's trajectory further increasing it's trajectory change.
Cool demonstration, hopefully not needed one day.
Rockets are using mass loss but there's more going on with the rapidly expanding gas causing the increased impulse.
If you think about it that's how a cannon works. The projectile gets pushed forwards and the barrel gets pushed in the opposite direction. Some of the larger ones can push their launcher back quite a bit more than you might expect.
My point is that this is actually a common failure of intuition. We tend to think of larger objects on earth as fixed and in our day to day life on dry land they often are (at least more or less) due to static friction.
A slightly more interesting observation (I think) is that if the bodies don't achieve escape velocity relative to one another then the forces all cancel out in the end. It just might take an arbitrarily long time in the case of similarly sized masses.
Mandatory sharing of Ben Afleck commentary speaking for all of us.
Since kinetic energy is proportional to v squared, that highly depends on how you measure v...
Instead of pointing out that exact measurements finally came in (of long term movement change), journalist instead focused on the obvious outcome that everyone expects and knows
The nitty-gritty details are what the article is for, not the title.
That's valuable not only for versatility, but also because it would really suck to send a spacecraft on a redirect mission only to find out that our assumptions about the asteroid's composition were wrong
You build a little factory and use chunks of the asteroid itself as thrust.
However, the most efficient method would be actually land (I know - maybe even impossible?) on it, and use propellers to change its trajectory. We don't have too much throwaway high-tech to crash it on asteroids...
It was in the context of hydrogen and I could have sworn it was flammable. But here is this encyclopedia telling me it's INflammable. It's... not flammable? Looked it up in the school library.
Thank you, that memory came up from the depths of time. Probably haven't thought about that in 30 years. Funny how we sometimes just didn't know stuff, and couldn't find out back then.
The only logical way out of the flammable/inflammable mess is to use 'flammable' and 'non-inflammable', which makes me so mad.
There are many counter-examples to your examples, such as “direct” and “indirect”, “humane” and “inhumane”.
The words used should be clear in their meaning. “Inflammable” is ambiguous, and it makes a great deal of difference which meaning is intended.
Flammable is unambiguous, as is non-inflammable. I’m forced to use these. Personally, I’m more in favour of flammable (able to catch fire) and inflammable (not able to catch fire).
They are not counter-example. You use the other "in-" prefix that take an adjective and give the opposite adjective, not the one that create a verb from a noun.
The historically correct term would be non-inflammable. The modern variant is non-flammable.
Similarly, inflammable is the historic term and flammable is the modern variant.
The confusion arises when people are exposed to the word flammable and then attempt to apply the usual rules to construct a word they've never actually used before.
This isn't the usual sort of inconsistency introduced by our fusing multiple incompatible languages. It's from the original Latin and I'm unclear what led to it. For example consider inflammable versus inhumane. It seems Latin itself used the prefix to mean different things - here on(fire) versus not(human). But confusingly it's ex to indicate location, despite ex also being the antonym of in. So ex equo means you are on horseback, not off it as I would have guessed.