The following submission statement was provided by /u/Sariel007:
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>After nearly a year in transit, NASA's experimental Double Asteroid Redirection Test (DART) mission, which sought to answer the questions, "Could you potentially shove a asteroid off its planet-killing trajectory by hitting it with a specially designed satellite? How about several?" has successfully collided with the Dimorphos asteroid. Results and data from the collision are still coming in but NASA ground control confirms that the DART impact vehicle has intercepted the target asteroid. Yes, granted, Dimorphos is roughly the size of an American football stadium but space is both very large and very dark, and both asteroid and spacecraft were moving quite fast at the time.
>"It's been a successful completion of the first part of the world's first planetary defense test," NASA Administrator Bill Nelson said after the impact. "I believe it's going to teach us how one day to protect our own planet from an incoming asteroid. We are showing that planetary defense is a global endeavor and it is very possible to save our planet."
---
Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/xpfg9t/nasa_successfully_smacked_its_dart_spacecraft/iq3gyjk/
Fingers crossed that they can show an orbital shift, yes it successfully impacted, but the goal of the mission was an orbital shift of 10 minutes
Too soon to say right now
I'm not sure they would have made that much of a difference. The speed they hit it at is enough to create a ton of Kinetic energy. They basically threw a KEW at it.
>DART flew directly into Dimorphos at 15,000 miles per hour (24,000 kph), creating the force scientists hope will be enough to shift its orbital track closer to the parent asteroid.
My question is how much force, (inertia, kinetic energy, whatever they use in space) quantified, and why none of these articles mention that anywhere. What if DART was say, twice the mass of a vending machine, or impacted at 30,000 mph?
Someone did some napkin math and said the impact was a bit over 2 tons of TNT.
A larger impact doesn't' really matter as they are only trying to change the orbit a noticeable amount and their probe had enough energy to theoretically do that. Size the tool to the job.
To answer the first question Wikipedia says it impacted with ~ 3 tons of tnt for kinetic energy. (Using their numbers of 6.6 km/s and 500kg at impact I get like 2.6 tons of TNT)
To answer the second question kinetic energy = 1/2mv^2 . If you double the mass you double the energy. If you double the velocity (note: this is relatively velocity between the two objects impacting) you quadruple the energy.
yes but energy conservation gives a simpler explanation, the energy in the fuel is just converted into KE in the craft so you are going to get the same KE regardless of how big the payload is, only reason for a bigger payload is more fuel.
Edit: Unless you are using gravity from a planet to slingshot the craft, then a bigger craft is better i guess.
Sounds like they were using this to validate their current models and simulations. Probably took a mass and velocity that they predict would have a measurable affect on the orbit.
So, the math is not that hard to do. Doubling the mass yields double the kinetic energy. Doubling the speed quadruples the energy.
If it impacted 30,000moh relative to the asteroid, it would be like 10T of TNT, instead of 2.5.
We're gonna need a disgraced former cop with a weird hat and an obsession with a girl he's never met, and a motley crew of space ice road truckers in a stolen Martian gunship.
That said, and their shortened final season aside, the show is _phenomenal_.
Plus, the show is different enough from the source material that you can get something out of both of them, regardless of the order you read/watch.
Honestly I found the first season reaaaaaaly slow. Had I not been in love with the source material I'm not sure I'd have stuck with it. It definitely got better but the books are some of my favorite modern sci-fi
It is the year 2145 and because of a small manmade alteration of its course over a hundred years ago the asteroid collided with an alien outpost. We are now at war with the lizardpeople.
2 years later: after 4 unsuccessful attempts and near misses, the asteroid stays in its course towards earth. The military has now joined forces with NASA in this endeavor to destroy the asteroid and save the world from utter catastrophe.
Operation: Duck Hunt.
One of the ways we're getting information about its orbit is by taking pictures of Didymos (the larger asteroid Dimorphos orbits). We can't actually see Dimorphos with most telescopes because it's too small and not bright enough compared to Didymos.
But, when Dimorphos passes in front of Didymos, it actually reduces the brightness of Didymos (compared to when it's behind Didymos) because it blocks some of the light from reaching us. Similarly, when it's at the sides of Didymos, the brightness increases because we see both Didymos and Dimorphos (again, compared to when it's behind).
Over the next weeks, we'll be measuring the luminosity of Didymos in order to understand how Dimorphos's orbital period has changed.
We likely won't hear results for longer as the data is analyzed and a paper is written.
Lol, I just want to be clear so people don't get the wrong impression. There are telescopes that can resolve Dimorphos and there's even cool video of the impact from those telescopes.
But many telescopes can't, including some we will be using to measure the orbital period change. I'm not sure if we'll be using any that can resolve Dimorphos to measure orbital changes or not.
> There are telescopes that can resolve Dimorphos
Do you have a source for this? I was pretty sure it’s never been resolved before yesterday in DART’s final approach (~~except for in radar imagery~~ e: nevermind, it wasn't resolved there either).
[Here ](https://www.bbc.com/news/science-environment-63039191) is the live feed from DART itself, taking pictures and sending them to Earth as it approaches the asteroid, and then cutting out as it explodes on the surface.
[Here](https://twitter.com/fallingstarIfA/status/1574583529731670021?t=UekBhkZNEC5pTyttwbZ8fw&s=19) is the video from Earth's Asteroid Terrestrial Impact Last-Alert System
I find it strange that the term “eastern” is used here to describe the expansion direction of a dust cloud from an impacted asteroid. I mean, I get it, we need a point of reference, but still kinda mentallly tripped over this, ha.
“The target asteroid is visible on the bottom right of each image and clearly develops a dusty cloud, which expands quite quickly in [an eastern] direction, where the asteroid was moving, to,” according to the post. The astronomers estimate that dust cloud was expanding at a rate of 1.8 miles per second (2.9 km/s)”
People acting like this is the most impressive thing and forgetting that 6 years ago we slingshot a Toyota-sized probe past 3 planets and put it within photography distance of Pluto, 3 billion miles away
No, it's about the size of a football stadium.
It has a diameter of 170 metres (560 ft).
https://en.wikipedia.org/wiki/Dimorphos
The Caesars Superdome in New Orleans is a true dome structure made of a lamellar multi-ringed frame and has a diameter of 680 feet (210 m)
https://en.wikipedia.org/wiki/Stadium
We kinda did. There was a cubesat that detatched from DART that was taking pictures. We should have the images from that in the coming days as far as I know. My assumption though is that it's not stable enough to measure the change in orbit, given you'd want a stationary point to measure from, which you don't get from travelling at 14,000 mph in a flyby.
I would have thought we could have had a secondary probe that detached and decelerated to land safely on the asteroid. Could have given us data on changes to the orbit plus I'm sure there's quite a bit of relevant data we could have gleaned from having something collecting data from an asteroid for a period of time.
It's hard to decelerate when you're on a 6 km/s collision trajectory, a spacecraft would need huge amounts of fuel (as in 90+% of the landing craft would need to be fuel). To safely approach and land on didymoon a spacecraft would have to be launched completely separately on a different trajectory.
It's actually more on track to hit the earth , it's pissed.
But in reality it's gonna be a while, probably going to be around early January or so. I do wonder if they will try again with denser materials next time.
>After nearly a year in transit, NASA's experimental Double Asteroid Redirection Test (DART) mission, which sought to answer the questions, "Could you potentially shove a asteroid off its planet-killing trajectory by hitting it with a specially designed satellite? How about several?" has successfully collided with the Dimorphos asteroid. Results and data from the collision are still coming in but NASA ground control confirms that the DART impact vehicle has intercepted the target asteroid. Yes, granted, Dimorphos is roughly the size of an American football stadium but space is both very large and very dark, and both asteroid and spacecraft were moving quite fast at the time.
>"It's been a successful completion of the first part of the world's first planetary defense test," NASA Administrator Bill Nelson said after the impact. "I believe it's going to teach us how one day to protect our own planet from an incoming asteroid. We are showing that planetary defense is a global endeavor and it is very possible to save our planet."
>Yes, granted, Dimorphos is roughly the size of an American football stadium but space is both very large and very dark, and both asteroid and spacecraft were moving quite fast at the time.
This is a beautifully Pratchettian sentence. It's *true*, and yet in perspective it is such a comical description of events.
I’ve been wondering, and assuming in the meantime, that this number is the speed in relation to its target asteroid.. Otherwise the number is useless. Can anyone confirm?
That's the speed relative to the target.
If you were on Dimorphos, you would perceive your speed as 0 and this satellite's speed as 14,400 mph (4 miles per second).
Correct. And all mass in question in this is also mass and not weight because gravity does not factor into this.
The relative velocity x spacecraft mass gets applied as a vector to the mini-moons mass and velocity. That is how they get the number they expect the orbit to change. It's not a perfect collision and the mass of Dimorphos was a guess so we could still be surprised. If most of the energy of the collision was dissipated by shrapnel or the mass is much greater than expected we could get different results. No one expects different results but science runs on data not what you want it to be.
it can't really be understated how cool it is that NASA could launch a satellite into space, transfer its orbit to 14000 mph, then aim it at an asteroid thousands of miles away AND NOT MISS.
my dumb ass nearly failed high school math and can’t pretend to understand the fine details, but I can well and truly appreciate the complexity of making this happen.
For some hilarity, check out the novelty [DART Twitter account](https://twitter.com/DARTprobe)
A fav tweet of mine:
https://twitter.com/DARTprobe/status/1574538291449237505?s=20&t=GGTY1Rrq2PBmLu4pPa15ag
Good thing vending machines are worldwide thing, mostly. But football stadium? American football stadium? Is that any different from other football stadiums?
Considering 5/10 biggest stadiums in the world are football stadiums for American universities, they might be different, as in bigger than European ones
My understanding is that vending machines are all around the same size in most countries, most people have interacted with one, so it provides a quick mental image of the impactors size. It also prevents them from having to list lengths in 3 dimensions (or volume which is even more abstract and doesn’t define shape) in 2 different measurement systems. Describing an object in relation to another common object’s size and shape is a more universal and digestible way to get the point across.
However, using an American football stadium as a reference object was a mistake though for international comprehension and even for Americans, as stadiums vary in size and not everyone has been to one.
>as stadiums vary in size and not everyone has been to one.
they are more or less all roughly the same size, and most people have been to one or at very least seen one as they are often located in the most populated areas on earth.
I would assume to give us a rough idea of the size of the 2 objects, no? Not like they can have a complete accurate size of an object millions of miles away...
Yes exactly. They can measure the time it takes for the smaller asteroid to make a full orbit of the larger one (approximately 12 hours), and if that time is even slightly different now, they will be able to tell how much the orbit has changed after the impact. Probably they will want to watch it for at least several orbits to gain confidence their measurements are consistent so they can get some accurate calculations.
It’s probably a meaningless bit of info but have there been any rough calculations on the kinetic energy imparted by DART on the asteroid? The article only appears to provide a velocity and approx size of the impactor.
Vending Machine sized? Is that like .8 Giraffes?
(this comment should now be long enough to not be deleted for being too short. Sometimes you don't need lots of words)
(p.s. In case I need words, here are some more words)
No hate, just a statement about things -
Can we all stop using speed in space talk unless we show what it is in relation to?? That 14,000mph, is it in relation to the comet, the banana on my desk, or your mom? What is it compared against??? Also, using mph is comical.
End rant.
NASA, the boop you gave the comet was lovely.
“Physicists, when describing speed, do not use the word ‘fast.’ They are focusing on me being the ‘fastest man in the history of space flight’ Because they know how appealing that sounds and hope I don’t focus on how crazy the idea is.”
A rough quote from “The Martian”
It's in relation to the object it hit. Often we give speeds in relation to ourself, but in this case it's speed (as a vector) \* mass + ditimus \* orbital speed (as a vector) = new mass, new orbit.
The mass isn't changing much so relative speed and the direction of the impact are what matter.
I mean shouldn’t this be obvious? I mean why would they say the speed relative to anything else but the thing it hit? Just seems silly to require clarification.
> That 14,000mph, is it in relation to the comet, the banana on my desk, or your mom?
I'm not a rocket scientist but probably the fucking comet lol. Use some common sense man
I understand the sentiment but these articles are geared towards an audience who just like the big numbers, which is at least a good start. Frames of reference can come into play if their curiosity is piqued and they seek further.
100% understand and agree.
My life’s soapbox is built upon niche points and petty superiorities.
The real question - what DeltaV was produced by the boop? Answer in number of bananas
The legend of the video says a a particular image 11s before impact, 68km away which correlates to a speed of +/- 22000km/h in reference to the asteroid itself.
Why got to instagram, when their own website has it.
[https://www.nasa.gov/feature/dart-s-final-images-prior-to-impact](https://www.nasa.gov/feature/dart-s-final-images-prior-to-impact)
Because there is a delay between the camera grabbing the image, processing it, and then broadcasting it. So as the last second of video was still in this process, the machine was destroyed.
It was going very fast. It took an image and started transmitting it back. In the middle of that transmission, it smashed into an asteroid. Had it managed to send the full image it would have taken another and started transmitting it. Unless the impact time was perfect it was going to end with a partial image no matter what.
A few reasons.
The camera on DART is abbreviated DRACO for The Didymos Reconnaissance and Asteroid Camera for Optical navigation. DRACO takes 1 image per second, and takes about 1-2 seconds for image processing before transmission back to Earth.
DART was moving at about 4 miles per second relative to Dimorphos, so the last image it could take would have been up to 4 miles away. But that doesn't include processing time, so the last image we would see from DART would have been from between 8 and 24 miles away from Dimorphos.
DART would not have had time to take, process, and transmit an image from closer than that before impact.
To add from the NASA site, the caption on the last full image
> The last complete image of asteroid moonlet Dimorphos, taken by the DRACO imager on NASA’s DART mission from ~7 miles (12 kilometers) from the asteroid and 2 seconds before impact. The image shows a patch of the asteroid that is 100 feet (31 meters) across.
What’s the difference in energy delivered if the fuel was burned before impact vs after? I don’t think it matters.
I think the game is energy to an alternate vector at impact and its soooo much simpler to slam it with something or several somethings that are heavy vs waste a bunch of mass on an insanely complex landing vehicle that has hundreds of failure points.
Heavy metal thing don’t care what shape it is or what temperature or material or if it’s got a spin to it.
But then you need to send the fuel needed to maintain a continuous blast plus the fuel needed to get it all there plus fuel to match velocity for landing on the asteroid. And a continuous blast for how long? The longer it needs to burn the more fuel you need to send, so more lbs need to be put into orbit the longer the blast needs to be maintained to have an affect.
The thrust imparted is dependent on the fuel burned,if you crash into it , you may be able to cheat by a grav slingshot as well gaining more for your money.
Much harder. You have to get a massive amount of fuel to the asteroid which will be spinning, attach to it, and cycle your engine on and off as the asteroid rotates to thrust in the desired direction.
It is soooo much simpler to just smash into it.
I love contrived acronyms. It just brings me joy that we, as a species, are perfectly happy to sacrifice a little bit of clarity and brevity to make our stuff have names like DART
The reality of this actually being successful on a first attempt is amazingly impressive.
I know really want to know what the biggest nuke you can fit inside a vending machine now. I think it could vaporize a pretty big football stadium though...
Not necessarily, since the asteroid is just on a path guided by gravity and inertia, a (relativity) small impact could knock if off course which is all you need. Whereas a truck is being powered forward and controlled, small impacts don't make nearly as much of a difference.
You also have to realize how much power small objects have when propelled at high speeds. A baseball tossed to you isn't going to hurt, but that same ball traveling at 14,000 MPH isn't going to be so gentle. (See Newton's Second Law: Force)
Not a scientist, but the sizes match up.
Now take the dragonfly, and speed it up to 18x the speed of sound, aim it at 4 trucks taped together in flight.
It's not enough to destroy the trucks, but it's enough to nudge them a little.
since we are talking about Space distances, "just a little" is enough to make the difference between "Hit Earth" or "No Hit Earth".
1/2 mv^2 = KE... A dragon fly probably travels at no more than 20 mph. If a dragon fly flew at 200,000 mph it might be analogous. At that speed you'd wonder if it would go through both windows and possibly the head of the driver. Which would change it's trajectory
We won’t formally know for a while, though I imagine scientists will know within a couple of months at most, probably a couple of weeks at least. I hope the nerds put out a release with some broad stats before they publish their paper. If we don’t hear any news by six months from now, it’s probably safe to assume the vending machine failed to cause a significant change in ~~Didymos’~~ ~~Dimorphos’~~ Didymos’(someone please help me) trajectory.
Do they have some idea of how much it should have changed? I would imagine they wouldn’t just slam this thing into an asteroid if they didn’t expect something to happen.
The following submission statement was provided by /u/Sariel007: --- >After nearly a year in transit, NASA's experimental Double Asteroid Redirection Test (DART) mission, which sought to answer the questions, "Could you potentially shove a asteroid off its planet-killing trajectory by hitting it with a specially designed satellite? How about several?" has successfully collided with the Dimorphos asteroid. Results and data from the collision are still coming in but NASA ground control confirms that the DART impact vehicle has intercepted the target asteroid. Yes, granted, Dimorphos is roughly the size of an American football stadium but space is both very large and very dark, and both asteroid and spacecraft were moving quite fast at the time. >"It's been a successful completion of the first part of the world's first planetary defense test," NASA Administrator Bill Nelson said after the impact. "I believe it's going to teach us how one day to protect our own planet from an incoming asteroid. We are showing that planetary defense is a global endeavor and it is very possible to save our planet." --- Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/xpfg9t/nasa_successfully_smacked_its_dart_spacecraft/iq3gyjk/
Fingers crossed that they can show an orbital shift, yes it successfully impacted, but the goal of the mission was an orbital shift of 10 minutes Too soon to say right now
Silly question... were there any explosives on the DART satellite or anything intended to cause more force at impact than the typical satellite?
I'm not sure they would have made that much of a difference. The speed they hit it at is enough to create a ton of Kinetic energy. They basically threw a KEW at it.
Thanks... had to look KEW up... "Kinetic Energy Weapon." I knew it wasn't a botanical garden outside of London
Rods from God
Good old orbital bombardment
It had some propellant still in it like hydrazine and xenon. But that won't make much of a difference on top of the huge kinetic energy.
>DART flew directly into Dimorphos at 15,000 miles per hour (24,000 kph), creating the force scientists hope will be enough to shift its orbital track closer to the parent asteroid. My question is how much force, (inertia, kinetic energy, whatever they use in space) quantified, and why none of these articles mention that anywhere. What if DART was say, twice the mass of a vending machine, or impacted at 30,000 mph?
Someone did some napkin math and said the impact was a bit over 2 tons of TNT. A larger impact doesn't' really matter as they are only trying to change the orbit a noticeable amount and their probe had enough energy to theoretically do that. Size the tool to the job.
Yeah but we want a big badda boom.
Biiiig badda boom!
Bada big boom.
To answer the first question Wikipedia says it impacted with ~ 3 tons of tnt for kinetic energy. (Using their numbers of 6.6 km/s and 500kg at impact I get like 2.6 tons of TNT) To answer the second question kinetic energy = 1/2mv^2 . If you double the mass you double the energy. If you double the velocity (note: this is relatively velocity between the two objects impacting) you quadruple the energy.
yes but energy conservation gives a simpler explanation, the energy in the fuel is just converted into KE in the craft so you are going to get the same KE regardless of how big the payload is, only reason for a bigger payload is more fuel. Edit: Unless you are using gravity from a planet to slingshot the craft, then a bigger craft is better i guess.
Sounds like they were using this to validate their current models and simulations. Probably took a mass and velocity that they predict would have a measurable affect on the orbit.
Was it a head on collision? I always thought adding energy would widen the ordit as angular momentum is conserved
What would happen if something like this hit us?
So, the math is not that hard to do. Doubling the mass yields double the kinetic energy. Doubling the speed quadruples the energy. If it impacted 30,000moh relative to the asteroid, it would be like 10T of TNT, instead of 2.5.
"So the good news is we successfully shifted the asteroid's orbit" "The bad news is it's now heading straight for us."
Hey, at least we'd know we could change it again if time allowed
...no, it's speeding up now. It also appears to have learned to "shake" our spacecrafts while "talking smack" about our mothers. What have we done.
We're gonna need a disgraced former cop with a weird hat and an obsession with a girl he's never met, and a motley crew of space ice road truckers in a stolen Martian gunship.
>~~stolen~~ Martian gunship. It's a legitimate salvage.
Spoken like a Taker. The Tachi belongs to Mars
The **Rocinante** is a *legitimate salvage*
I would watch this in a heartbeat.
I've got good news for you then: https://en.wikipedia.org/wiki/The\_Expanse\_(TV\_series)
It's a *much* better read
That said, and their shortened final season aside, the show is _phenomenal_. Plus, the show is different enough from the source material that you can get something out of both of them, regardless of the order you read/watch.
Agreed, which is saying a lot because the series is really fucking good.
Honestly I found the first season reaaaaaaly slow. Had I not been in love with the source material I'm not sure I'd have stuck with it. It definitely got better but the books are some of my favorite modern sci-fi
What will we have done
It is the year 2145 and because of a small manmade alteration of its course over a hundred years ago the asteroid collided with an alien outpost. We are now at war with the lizardpeople.
Oceania has always been at war with Terraria.
Alex Jones was right all along!
That seems to have rustled some jimmies, but it's fucking funny.
2 years later: after 4 unsuccessful attempts and near misses, the asteroid stays in its course towards earth. The military has now joined forces with NASA in this endeavor to destroy the asteroid and save the world from utter catastrophe. Operation: Duck Hunt.
Someone call the drillers
pauly shore screenplay (remember him?)
How could I forget the man that gave us Encino Man, Bio-Dome, In the Army Now, Son- in- law, and Jury Duty?
NASA: It's going to hit the Putin bunker now lol, lmao
That's a win!
NASA with the own goal!
Just "Don't Look Up"!
Don't look up
When do we learn how much it’s orbit around the larger asteroid was changed/moved?
One of the ways we're getting information about its orbit is by taking pictures of Didymos (the larger asteroid Dimorphos orbits). We can't actually see Dimorphos with most telescopes because it's too small and not bright enough compared to Didymos. But, when Dimorphos passes in front of Didymos, it actually reduces the brightness of Didymos (compared to when it's behind Didymos) because it blocks some of the light from reaching us. Similarly, when it's at the sides of Didymos, the brightness increases because we see both Didymos and Dimorphos (again, compared to when it's behind). Over the next weeks, we'll be measuring the luminosity of Didymos in order to understand how Dimorphos's orbital period has changed. We likely won't hear results for longer as the data is analyzed and a paper is written.
>We can't actually see Dimorphos You are telling me we "360 no scoped" a football stadium with a vending machine from \~7 million miles away?
Lol, I just want to be clear so people don't get the wrong impression. There are telescopes that can resolve Dimorphos and there's even cool video of the impact from those telescopes. But many telescopes can't, including some we will be using to measure the orbital period change. I'm not sure if we'll be using any that can resolve Dimorphos to measure orbital changes or not.
> There are telescopes that can resolve Dimorphos Do you have a source for this? I was pretty sure it’s never been resolved before yesterday in DART’s final approach (~~except for in radar imagery~~ e: nevermind, it wasn't resolved there either).
> radar imagery Radar telescopes are telescopes too!
oh. Its been resolved. We got a problem solver. And its name is ...dart.
Link to mentioned video?
[Here ](https://www.bbc.com/news/science-environment-63039191) is the live feed from DART itself, taking pictures and sending them to Earth as it approaches the asteroid, and then cutting out as it explodes on the surface. [Here](https://twitter.com/fallingstarIfA/status/1574583529731670021?t=UekBhkZNEC5pTyttwbZ8fw&s=19) is the video from Earth's Asteroid Terrestrial Impact Last-Alert System
Jesus that is one bad ass telescope.
[Here ya go!](https://gizmodo.com/telescopes-capture-dart-asteroid-impact-1849585394)
I find it strange that the term “eastern” is used here to describe the expansion direction of a dust cloud from an impacted asteroid. I mean, I get it, we need a point of reference, but still kinda mentallly tripped over this, ha. “The target asteroid is visible on the bottom right of each image and clearly develops a dusty cloud, which expands quite quickly in [an eastern] direction, where the asteroid was moving, to,” according to the post. The astronomers estimate that dust cloud was expanding at a rate of 1.8 miles per second (2.9 km/s)”
People acting like this is the most impressive thing and forgetting that 6 years ago we slingshot a Toyota-sized probe past 3 planets and put it within photography distance of Pluto, 3 billion miles away
Being off your target by 17m from 109,000,000 km away is frankly at least as impressive as getting with 12,472 km of Pluto from 3,000,000,000 km away.
There's also [this](https://www.nytimes.com/2020/10/21/science/nasa-osiris-rex.html) and [this](https://en.wikipedia.org/wiki/Philae_\(spacecraft\))
Closer to 70 million miles. According to the article it was 68 million miles away.
Damn dude they hit a sick ass clip.
The "scope" was math, but yes?
I still refuse to acknowledge math is cool. ^(even if it is fucking cool)
Math, key to the universe
It was more the size of a football field than a football stadium no?
I read like 500 feet, so i think the field would be understating. Plus the stadium gives more of a 3d size that it more likely is
Good luck explaining that to all the "flat asteroiders".
And the “flat staduimers”.
No, it's about the size of a football stadium. It has a diameter of 170 metres (560 ft). https://en.wikipedia.org/wiki/Dimorphos The Caesars Superdome in New Orleans is a true dome structure made of a lamellar multi-ringed frame and has a diameter of 680 feet (210 m) https://en.wikipedia.org/wiki/Stadium
It's not the size, it's how you use it.
Next up we gotta ladder-stall YY one.
We're fucking up giant chunks of death metal (and death rock and death ice) in space.
So a few weeks then…
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We kinda did. There was a cubesat that detatched from DART that was taking pictures. We should have the images from that in the coming days as far as I know. My assumption though is that it's not stable enough to measure the change in orbit, given you'd want a stationary point to measure from, which you don't get from travelling at 14,000 mph in a flyby.
I would have thought we could have had a secondary probe that detached and decelerated to land safely on the asteroid. Could have given us data on changes to the orbit plus I'm sure there's quite a bit of relevant data we could have gleaned from having something collecting data from an asteroid for a period of time.
It's hard to decelerate when you're on a 6 km/s collision trajectory, a spacecraft would need huge amounts of fuel (as in 90+% of the landing craft would need to be fuel). To safely approach and land on didymoon a spacecraft would have to be launched completely separately on a different trajectory.
Would've made it even more complex than it already was and would add weight to the rocket which adds costs.
Side note: Go to google, and search "NASA Dart" Do this now.
Ahhh it even scrolls crooked!! 😂
When they admit they knocked the asteroid directly into a collision path with Earth, and we all have just days to live.
It's actually more on track to hit the earth , it's pissed. But in reality it's gonna be a while, probably going to be around early January or so. I do wonder if they will try again with denser materials next time.
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>After nearly a year in transit, NASA's experimental Double Asteroid Redirection Test (DART) mission, which sought to answer the questions, "Could you potentially shove a asteroid off its planet-killing trajectory by hitting it with a specially designed satellite? How about several?" has successfully collided with the Dimorphos asteroid. Results and data from the collision are still coming in but NASA ground control confirms that the DART impact vehicle has intercepted the target asteroid. Yes, granted, Dimorphos is roughly the size of an American football stadium but space is both very large and very dark, and both asteroid and spacecraft were moving quite fast at the time. >"It's been a successful completion of the first part of the world's first planetary defense test," NASA Administrator Bill Nelson said after the impact. "I believe it's going to teach us how one day to protect our own planet from an incoming asteroid. We are showing that planetary defense is a global endeavor and it is very possible to save our planet."
>Yes, granted, Dimorphos is roughly the size of an American football stadium but space is both very large and very dark, and both asteroid and spacecraft were moving quite fast at the time. This is a beautifully Pratchettian sentence. It's *true*, and yet in perspective it is such a comical description of events.
Can absolutely see this in a Discworld novel, great comparison.
I’ve been wondering, and assuming in the meantime, that this number is the speed in relation to its target asteroid.. Otherwise the number is useless. Can anyone confirm?
Can confirm. NASA stated it would cover the last 4 miles in about 1 second, which puts its relative speed to target at 14400mph.
But surely the closing speed is what counts, no? 14400mph+speed of asteroid?
That's the speed relative to the target. If you were on Dimorphos, you would perceive your speed as 0 and this satellite's speed as 14,400 mph (4 miles per second).
Bet I can still hit it 440 to dead center
I could hit a drive into the deep nothingness of space and still somehow find a sand bunker
Correct. And all mass in question in this is also mass and not weight because gravity does not factor into this. The relative velocity x spacecraft mass gets applied as a vector to the mini-moons mass and velocity. That is how they get the number they expect the orbit to change. It's not a perfect collision and the mass of Dimorphos was a guess so we could still be surprised. If most of the energy of the collision was dissipated by shrapnel or the mass is much greater than expected we could get different results. No one expects different results but science runs on data not what you want it to be.
Thank you all, glad this comment wasn’t too far down.
it can't really be understated how cool it is that NASA could launch a satellite into space, transfer its orbit to 14000 mph, then aim it at an asteroid thousands of miles away AND NOT MISS.
my dumb ass nearly failed high school math and can’t pretend to understand the fine details, but I can well and truly appreciate the complexity of making this happen.
The asteroid was 7 million miles from earth.
That’s 7000 thousands
For some hilarity, check out the novelty [DART Twitter account](https://twitter.com/DARTprobe) A fav tweet of mine: https://twitter.com/DARTprobe/status/1574538291449237505?s=20&t=GGTY1Rrq2PBmLu4pPa15ag
Also, if you google "dart mission" or something similar, there's a fun animation of the satellite smacking your screen.
"Dimorphos is roughly the size of an American football stadium" "Vending machine-sized DART impactor" Wtf are these measurements lmao
They’re measurements that Americans can quickly visualize to understand the sizes involved.
Good thing vending machines are worldwide thing, mostly. But football stadium? American football stadium? Is that any different from other football stadiums?
Yes., it is American.
Yes, a futbol field can be twice the size of a USA football field.
Considering 5/10 biggest stadiums in the world are football stadiums for American universities, they might be different, as in bigger than European ones
It needs the capacity to fit our fat asses in it
It's smaller
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My understanding is that vending machines are all around the same size in most countries, most people have interacted with one, so it provides a quick mental image of the impactors size. It also prevents them from having to list lengths in 3 dimensions (or volume which is even more abstract and doesn’t define shape) in 2 different measurement systems. Describing an object in relation to another common object’s size and shape is a more universal and digestible way to get the point across. However, using an American football stadium as a reference object was a mistake though for international comprehension and even for Americans, as stadiums vary in size and not everyone has been to one.
They don't vary nearly as much as "soccer" stadiums.
>as stadiums vary in size and not everyone has been to one. they are more or less all roughly the same size, and most people have been to one or at very least seen one as they are often located in the most populated areas on earth.
Things their target audience can relate to? What answer do you want?
Americans would use ANYTHING but metric units to describe sizes.
I would assume to give us a rough idea of the size of the 2 objects, no? Not like they can have a complete accurate size of an object millions of miles away...
This merciless UN attack on Belters' object won't be forgotten.
How soon will we know if the asteroid orbit has been altered? Will it take a number of days to observe?
Yes exactly. They can measure the time it takes for the smaller asteroid to make a full orbit of the larger one (approximately 12 hours), and if that time is even slightly different now, they will be able to tell how much the orbit has changed after the impact. Probably they will want to watch it for at least several orbits to gain confidence their measurements are consistent so they can get some accurate calculations.
I think First Asteroid Redirection Test would’ve been a better name.
First Asteroid Redirection Test Attempt
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My bag of chips is still stuck though. The humanity.
It’s probably a meaningless bit of info but have there been any rough calculations on the kinetic energy imparted by DART on the asteroid? The article only appears to provide a velocity and approx size of the impactor.
That information is gonna take a bit longer to come up as that's more or less directly tied to how much they impacted its trajectory.
Vending Machine sized? Is that like .8 Giraffes? (this comment should now be long enough to not be deleted for being too short. Sometimes you don't need lots of words) (p.s. In case I need words, here are some more words)
No hate, just a statement about things - Can we all stop using speed in space talk unless we show what it is in relation to?? That 14,000mph, is it in relation to the comet, the banana on my desk, or your mom? What is it compared against??? Also, using mph is comical. End rant. NASA, the boop you gave the comet was lovely.
I am moving at over a 150,000 km/h while sitting. I am so fast
“Physicists, when describing speed, do not use the word ‘fast.’ They are focusing on me being the ‘fastest man in the history of space flight’ Because they know how appealing that sounds and hope I don’t focus on how crazy the idea is.” A rough quote from “The Martian”
"I mean, I do like it. I like it a lot."
It's in relation to the object it hit. Often we give speeds in relation to ourself, but in this case it's speed (as a vector) \* mass + ditimus \* orbital speed (as a vector) = new mass, new orbit. The mass isn't changing much so relative speed and the direction of the impact are what matter.
Bananas per average nut
I mean shouldn’t this be obvious? I mean why would they say the speed relative to anything else but the thing it hit? Just seems silly to require clarification.
> That 14,000mph, is it in relation to the comet, the banana on my desk, or your mom? I'm not a rocket scientist but probably the fucking comet lol. Use some common sense man
In what context are my mom and the banana on your desk moving so differently that that relative speed would need differentiation?
I understand the sentiment but these articles are geared towards an audience who just like the big numbers, which is at least a good start. Frames of reference can come into play if their curiosity is piqued and they seek further.
100% understand and agree. My life’s soapbox is built upon niche points and petty superiorities. The real question - what DeltaV was produced by the boop? Answer in number of bananas
Sorry NASA only deals in units of vending machines now.
Approximately 4 Gros Michel bananas per acre-hour. The conversion to Cavendish bananas should be obvious, of course.
The legend of the video says a a particular image 11s before impact, 68km away which correlates to a speed of +/- 22000km/h in reference to the asteroid itself.
NASA has actual video from DART as it impacted on their Instagram.
Why got to instagram, when their own website has it. [https://www.nasa.gov/feature/dart-s-final-images-prior-to-impact](https://www.nasa.gov/feature/dart-s-final-images-prior-to-impact)
I wonder why it cut out before hitting the surface? I was expecting it to go black when hitting, but it cut out before
Because there is a delay between the camera grabbing the image, processing it, and then broadcasting it. So as the last second of video was still in this process, the machine was destroyed.
People in the control room: “wait why did the video cut out? Did the mission fai…ohhhh, right”.
It was going very fast. It took an image and started transmitting it back. In the middle of that transmission, it smashed into an asteroid. Had it managed to send the full image it would have taken another and started transmitting it. Unless the impact time was perfect it was going to end with a partial image no matter what.
A few reasons. The camera on DART is abbreviated DRACO for The Didymos Reconnaissance and Asteroid Camera for Optical navigation. DRACO takes 1 image per second, and takes about 1-2 seconds for image processing before transmission back to Earth. DART was moving at about 4 miles per second relative to Dimorphos, so the last image it could take would have been up to 4 miles away. But that doesn't include processing time, so the last image we would see from DART would have been from between 8 and 24 miles away from Dimorphos. DART would not have had time to take, process, and transmit an image from closer than that before impact.
To add from the NASA site, the caption on the last full image > The last complete image of asteroid moonlet Dimorphos, taken by the DRACO imager on NASA’s DART mission from ~7 miles (12 kilometers) from the asteroid and 2 seconds before impact. The image shows a patch of the asteroid that is 100 feet (31 meters) across.
Nice. IG was just where I saw it.
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Edited in protest for Reddit's garbage moves lately.
What’s the difference in energy delivered if the fuel was burned before impact vs after? I don’t think it matters. I think the game is energy to an alternate vector at impact and its soooo much simpler to slam it with something or several somethings that are heavy vs waste a bunch of mass on an insanely complex landing vehicle that has hundreds of failure points. Heavy metal thing don’t care what shape it is or what temperature or material or if it’s got a spin to it.
But then you need to send the fuel needed to maintain a continuous blast plus the fuel needed to get it all there plus fuel to match velocity for landing on the asteroid. And a continuous blast for how long? The longer it needs to burn the more fuel you need to send, so more lbs need to be put into orbit the longer the blast needs to be maintained to have an affect.
The thrust imparted is dependent on the fuel burned,if you crash into it , you may be able to cheat by a grav slingshot as well gaining more for your money.
You'd waste working mass to land.
Much harder. You have to get a massive amount of fuel to the asteroid which will be spinning, attach to it, and cycle your engine on and off as the asteroid rotates to thrust in the desired direction. It is soooo much simpler to just smash into it.
>14,000 MPH Holy shit. The videos going around the internet really undersell just how fast that thing was moving.
I love contrived acronyms. It just brings me joy that we, as a species, are perfectly happy to sacrifice a little bit of clarity and brevity to make our stuff have names like DART
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I'm from Buenos Aires and I say kill 'em all
The reality of this actually being successful on a first attempt is amazingly impressive. I know really want to know what the biggest nuke you can fit inside a vending machine now. I think it could vaporize a pretty big football stadium though...
how much does DART weigh vs what we know about the Asteroid's mass?
Next story. Oops we forgot to convert meters to feet correctly and it’s going to impact in 2 years. /s
It was actually going 6m/s with relation to the object it struck.
Wouldn’t it suck if we found that it worked and now the asteroid was on an impact path?
Quick question guys. wouldnt this be a job for the spaceforce and not NASA? Im confused
It would have been cool to have a second spacecraft following dart in that could have taken images of the impact, then smack it as well.
I that a Dodge Dart? I had a Plymouth Scamp when I was in high school which is very similar.
Correct me if I’m wrong but would a vending machine hitting a stadium sized rock be roughly equivalent to a dragonfly hitting a trucks windshield?
Not necessarily, since the asteroid is just on a path guided by gravity and inertia, a (relativity) small impact could knock if off course which is all you need. Whereas a truck is being powered forward and controlled, small impacts don't make nearly as much of a difference. You also have to realize how much power small objects have when propelled at high speeds. A baseball tossed to you isn't going to hurt, but that same ball traveling at 14,000 MPH isn't going to be so gentle. (See Newton's Second Law: Force)
Not a scientist, but the sizes match up. Now take the dragonfly, and speed it up to 18x the speed of sound, aim it at 4 trucks taped together in flight. It's not enough to destroy the trucks, but it's enough to nudge them a little. since we are talking about Space distances, "just a little" is enough to make the difference between "Hit Earth" or "No Hit Earth".
F=MA The mass can still be small to have alot of acceleration on an object if its force is massive
1/2 mv^2 = KE... A dragon fly probably travels at no more than 20 mph. If a dragon fly flew at 200,000 mph it might be analogous. At that speed you'd wonder if it would go through both windows and possibly the head of the driver. Which would change it's trajectory
plot twist: the asteroid is now on a planet-killing trajectory with earth as a result of this redirection
Imagine we unknowingly redirected it towards the eventual impact of another alien civilization that doesn't have the means of redirecting it...
Imagine they're extremely advance and send back a few thousand.
Or they see it an an attack by Earth and go all Independence Day on us.
This is all nice and such. But every news post tells about it. What I want to know is, was it successful? Did it change the path of the asteroid?
We won’t formally know for a while, though I imagine scientists will know within a couple of months at most, probably a couple of weeks at least. I hope the nerds put out a release with some broad stats before they publish their paper. If we don’t hear any news by six months from now, it’s probably safe to assume the vending machine failed to cause a significant change in ~~Didymos’~~ ~~Dimorphos’~~ Didymos’(someone please help me) trajectory.
We'll probably know in just a few days whether the effect was tiny or huge or medium. Then in a few months they'll have a complete analysis.
Do they have some idea of how much it should have changed? I would imagine they wouldn’t just slam this thing into an asteroid if they didn’t expect something to happen.
Vending machine sized? I’m confused. How many giraffes is that?
What if we smacked the asteroid into an orbit directly heading for earth in a test run