A planet-killer asteroid colliding with earth–we’ve all thought about it. Bruce Willis was in a movie about it. Some bumper stickers & commenters here regularly try to will it into happening. And now, at long last, we’re doing something to prepare for mitigating this existential risk.
You may have heard of NASA’s Double Asteroid Redirection Test, or DART, mission. It launched last November and is very straightforward: they’re going to crash a probe into an asteroid to see what happens. The asteroid in question is named Dimorphos; it is about 500 feet wide and orbits another asteroid named Didymos. Physics being fairly straightforward at this scale, Didymos’s orbit will change to be closer to Dimorphos. The question is, by how much? Knowing that can tell us how much wiggle room we have for detecting and swatting away an actual planet-killer. Such a rock is practically inevitable, and with any luck humanity will be around to see it, so it’s good that we’re getting started now. The mission isn’t cheap–$324 million–but measured against the value of the only world known so far to harbor life, that’s peanuts.
Existential risk is a funny thing. Right now “AI alignment”–preventing Skynet–is sucking up all the oxygen in the STEM imagination, despite the complete lack of evidence that it is a real problem, to say nothing of being an urgent one. Even so we probably spend between ten and fifty million dollars a year on it. Maybe this is fine–every dollar Peter Thiel spends on this is one less dollar he has to usher in the Dark Enlightenment–but I for one am glad we have a government that’s willing to shell out for things that actually matter.
Here’s space.com with some more background. You can watch live as our probe (hopefully) goes kablooey on NASA TV, with coverage starting at 6pm Eastern. The 14,000 mph collision is schedule for 7:14.
Open thread, also!
scav
A sort of Demolition Derby for nerds? Or maybe reallly reallly slow Snooker.
sab
I am 68 years old. Asteroids hitting the Earth is way down in my list of concerns.
Hey, if I weren’t so lefty I could be a Villages voter. Oops no. Taxes is their agenda. Taxes impact them now. Survival of their property value or their world is after their life.
If they loved their family in the MidWest they would still be there.
Baud
Nothing good!
MisterForkbeard
Off topic: I’m in Vegas for a work thing. Been here an hour. Forgot how much Vegas sucks.
Math Guy
You have to take the long view to appreciate the significance of this experiment.
C Stars
Oooh, cool, thanks for posting MMM.
PaulWartenberg
WHAT
COULD
POSSIBLY
GO
WRUNG
Yutsano
SPAAAAAAAAAAACE!!!
SpaceUnit
I’m surprised that NASA would choose as their target an asteroid that’s orbiting another, larger asteroid. Seems to unnecessarily complicate the physics. I can’t help but think that you’d get a clearer set of data points by ramming a singular object on a straight trajectory.
But I am a very simple space unit.
Martin
@Math Guy: Yep. There are no known threats for the next 100 years.
But if we do find a body that would strike earth 150 years from now, you want to poke it soon, because the poke 100 years from now will need to be MUCH bigger and harder to do.
The lesson is one we didn’t learn from climate change – the earlier you address it, the cheaper and easier it is. The later you wait, the more painful it becomes. This doesn’t seem like a lesson that mathematicians and physicists should uniquely understand, but sometimes it seems that way.
Major Major Major Major
@Martin:
Of course, we haven’t even come close to knowing about all the planet-killers in the vicinity.
eclare
@sab: How are the spouse and your menagerie of animals?
Baud
Is there a camera on the probe? That’s one thing Musk did right when he launched that car into space.
Martin
@SpaceUnit: Oh, no – it makes perfect sense.
Yes, it’s a somewhat more complex target to hit, but these bodies are small enough that their gravitational attraction is pretty tenuous. It doesn’t take much effort to disrupt that, which means we can get pretty good measurements of the impact of the mission. That’s the goal – with a high velocity kinetic impact, how much of the added momentum to the system that the spacecraft introduces is preserved by the body being impacted. Is it 1%? 10%? More?
This is about giving us a baseline from which to work. But in order to set that baseline, we needed a system that was sensitive enough that we could have a measurable effect.
eclare
@Baud: Wasn’t that Napoleon’s two step plan for Waterloo:
1. Show up
2. See what happens
Martin
@Baud: There’s two. There’s one on the probe and there’s one on a cubesat that is doing a flyby to see the impact and the aftermath.
Goku (aka Amerikan Baka)
@Martin:
Eh, silly libtard. Haven’t you ever watched Armageddon? All you gotta do is nuke the big space rock and save the day! /s
Ken
Hmm, watch it now, or wait until tomorrow and see if there is a follow-up article where the phrases “unexpected deflection” and “planetary extinction event” appear?
Baud
@Ken:
I’m personally expecting reports of awakening the Didymos Crystalline Entity.
SiubhanDuinne
@SpaceUnit:
For some reason, my eyes failed to notice the first two letters of “orbiting,” so I was left wondering what reckless instinct would possess an asteroid to bite another, larger asteroid.
ColoradoGuy
If there are any other habitable (15 to 25% oxygen atmosphere, with liquid water on the surface) worlds, it looks they are at a stupendous distance – 10 to 100 light-years. Or more. Maybe much more.
In the physics we have now, the fastest we can ever build a spaceship seems to between 10 to 20% of lightspeed … with fusion or antimatter propulsion and ultra-powerful laser boost (output exceeding all of Earth’s energy at present). Maybe 100 to 200 years in our future IF there is no Dark Age in between.
So traveling to another habitable world is not going to be a walk in the park. More likely, artificial hibernation for centuries, and considerable rehab on the other end. Not like Star Trek at all.
dmsilev
@SpaceUnit: The spacecraft is a lot smaller than the asteroid, so even with a fairly high-speed collision, it’s not going to change the trajectory all that much. It’s a lot easier to measure things like “the orbital period of the two asteroids has changed by a bit” than it is to measure “the overall trajectory relative to the Sun or Earth has changed by a bit”.
Major Major Major Major
@SpaceUnit: if I had to guess, it’s because they wanted to hit something small but it’s a lot easier to aim at something big and then refine the course when you’re close.
SpaceUnit
@Martin:
But the margin of error incurred by estimating the mass of two objects is increased.
dmsilev
NASA just announced that “the DART spacecraft has acquired target lock on Dimorphos.”. Today, we’re living inside some really cheesy SF thriller.
PaulWartenberg
What happens if at the last second the DART camera spots a terrified extraterrestrial looking upward at the crashing space probe?! would we be starting an intergalactic war?!?!?!
Martin
@Major Major Major Major: Sorta. The good news is that the biggest threats are, actually bigger. Which means they’re easier to detect. We believe we’ve surveyed all of the planet killer sized objects that have earth crossing orbits and almost all continent threat sized objects.
Where there’s more work to do is on city/region impact sized objects. For Tunguska sized objects we perhaps have surveyed 25% or less.
So, the 100 year thing refers to the continent/planetary sized threats. Smaller ones could be on the calendar.
And part of the survey is measuring their position/velocity well enough that we can make future predictions. So it turns in a process a bit like hurricane forecasting with a cone of uncertainty, and whether or not the earth lands in that cone. That will continue to improve with better telescopes/spacecraft, etc.
NEO Surveyor is supposed to launch in a few years and is dedicated to this activity. It’ll sit at Earth/Sun L1 and look for asteroids 140m and larger. Congress actually mandated NASA prioritize identifying all 140m and larger earth crossers back in 2005.
bjacques
They missed a real opportunity to name the other asteroid Epididymos…a throbbing, purple-veined dick joke—in SPAAACE!
PaulWartenberg
@eclare:
Napoleon after Waterloo:
1. Fucked Around.
2. Found Out.
dmsilev
@SpaceUnit: Two bodies orbiting each other is something we understand very very well. Also, some of the unknown variables, like the exact mass of the two objects, don’t affect the orbital solution. That helps.
Ceci n est pas mon nym
I have always laughed at the idea of deflecting an asteroid by hitting it this way, or by setting off a bunch of nukes. The rock is just too big.
I found the NASA site for the mission, and here are the numbers: the DART spacecraft is 570 kg. The rock is estimated to be 5 billion kg. And they say this: “the impulse of energy that DART delivers to Dimorphos is low and cannot disrupt the asteroid” (emphasis mine)
So I’m not quite clear what they expect here. I guess the idea is that because the gravitational force between two rocks is so small, the effect on the orbiting body will be measurable.
Major Major Major Major
@Martin: they didn’t provide the funding to match the task, unfortunately, but we’ll get there! And yes you’re right I was being inexact. There’s still plenty of undetected stuff out there that could fuck us up one way or another.
Ceci n est pas mon nym
NASA has two feeds: the main broadcast (same as above I think), and the “DRACO camera feed”. Anybody know what that second one is? Is this just the difference between the channel with talking heads (main feed) and the spacecraft camera?
Martin
@SpaceUnit: True, but if you were hitting a sun-orbiting asteroid, you’d never be able to measure the change in velocity because of how strongly coupled that system is.
A LOT of experiments in physics require constructing a system with loose coupling so that any perturbation of that system is magnified enough that you can measure it. Even as an undergrad you learn how to do experiments to measure the speed of light, charge of an electron, etc. that all involve constructing these systems that enable measurement, and then they drill you through the process of measuring error, blah blah blah.
Major Major Major Major
@Ceci n est pas mon nym: when something is 300 million miles away, even the tiniest nudges make a big difference. And of course any actual mission would be far larger.
ETA also they don’t want to disrupt or destroy it!
sab
@eclare: We are great. Cats have their current late summer flea problem. Seriously, fleas are your worst issue?
Husband who has spent two months collapsed by back surgery gone wrong is much better. He thinks he is about 55%. He walks only with a cane. He can lift 20 lbs. He can drive. He can shower.
He is in pain, sometimes a lot, but vastly less than it used to be and every hope it wont’t last long.
I really admire him for creaking along in this slow process and rarely complaining. Women are supposed to quietly bear every burden. But also men are supposed to pretend that they feel no pain. Husband woke himself up screaming with pain every time he rolled over.That was real and he is a stoic.
SpaceUnit
@dmsilev:
Well I’m guessing you guys are right because this is what NASA has chosen to do.
Sometimes I think they just like to make things complicated. Suppose I don’t blame them. If you’ve got all that brainpower why not use it.
C Stars
@ColoradoGuy:
I actually saw a Star Trek episode with this EXACT premise in the last couple of months. Maybe it was Voyager? Arrgh now I have to hunt it down…
But yes I understand you’re saying my kids won’t get to be the next Picard. Boo hoo.
Martin
@Major Major Major Major: Yeah, but you start with the species eradication stuff and work your way down to the Tampa eradication stuff.
Martin is worried about Adam.
CaseyL
The NASA chat is very helpful, because all I see is a little dot bobbing up and down, getting infinitesimally larger.
ETA:… when they don’t cut to the mission crew talking. History of the mission, etc.
Martin
@Ceci n est pas mon nym: Yes. the main feed gives you the commentary. The alternate feed is so that guys like Neil DeGrasse Tyson can provide his own voice over for his own channel, that kind of thing.
Mike in NC
Rooting for an asteroid to take out Mar-A-Lago.
eclare
@PaulWartenberg: Hahaha…I hope this has a better result.
Ceci n est pas mon nym
@Major Major Major Major: NASA scientist (Dr. Statler) just said “change in the orbital period”. So as I’d expect, that’s what they’re looking for, not any actual deflection of the path.
eclare
@sab: Sounds like things are improving, if slowly! That the spouse can do those things for himself is a huge relief, I’m sure. Thanks for the update!
Major Major Major Major
@Ceci n est pas mon nym: that is a deflection in the path though. It indicates a change in altitude/speed.
Another Scott
@sab: I’m glad for both of you that his recovery is continuing. Hang in there.
Cheers,
Scott.
Ken
@PaulWartenberg: Any aliens able to cross interstellar space will be highly advanced, so will forgive us as required by the moral principles of cosmic oneness. Or crush is like flies. Either way, no need to worry about war.
SFBayAreaGal
T-minus 7:00
CaseyL
5 minutes to impact. Target looks like an actual rock now!
dmsilev
Five minutes to go. No more commands to send (speed of light…).
CaseyL
Seems to be coming in a little high; I am concerned.
Woops – I was looking at the wrong rock!
SpaceUnit
Woo Hoo!
SpaceUnit
Dimorphus fucked around.
Now it’s gonna find out.
PaulWartenberg
THE QUARTERBACK IS TOAST!!!
Baud
Red screen of death!
japa21
Unbelievable.
Alison Rose 💙🌻💛
WOOT!! That was the coolest, weirdest, nerdiest thing I’ve seen in a long time.
Baud
And thus begins the First Galactic War.
CaseyL
IMPACT! They got it!
japa21
The resolution on those last shots were almost as good as Bill in Glendale or Albatrossity are able to get.
Another Scott
What an interesting looking rock.
Did it hit about 10s early, or is that just the various lags? Either way, those guys and gals that love orbital mechanics did a fantastic job.
Cheers,
Scott.
Ceci n est pas mon nym
I found myself more affected by the last few frames than by impact. Just amazing to see an asteroid that close. I was really surprised to see loose rocks on the surface.
I said to my wife there’s probably an enormous amount of science to be done just from those last few frames.
sab
I am 68. I think this planetary defense is an incredibly stupid waste of taxpayer money.
My grand-daughter is 21. She thinks this planetary defense might be worth looking into.
I will probably be dead. She and hers might need the help.
Baud
@sab:
Earthhater.
Alison Rose 💙🌻💛
@Ceci n est pas mon nym: Same! I could feel my eyes getting wider and wider. That was so amazing.
SpaceUnit
That was for the dinosaurs, stupid space rocks!!!
Baud
@SpaceUnit:
Haha. A dish best served cold.
bbleh
@sab: ehh, the whole thing’s gonna get turned into a molten fireball and then vaporized when the sun exhausts its core fuel and begins expanding, so why bother?
Now which channel is showing Matlock?
Scamp Dog
@PaulWartenberg: No, it would be an intra-solar system war. The intergalactic war starts in 4 or 5 billion years when the Andromeda galaxy collides with the Milky Way. So we probably want a few in-system space wars before then to get in practice, right?
Princess
Where’s the KA-boom? I was expecting an asteroid-shattering KA-boom.
sab
@Baud: Youngster, aren’t you?
Cmorenc
Much more likely threat than planet-killer asteroids are the far more common city-killer size asteroids that aren’t large enough to be reliably detectable in time for a deflection mission. Consider the small asteroid that exploded a few years ago over a thinly populated region of Siberia, which was a total surprise, but could have eg devastated moscow or london had it hit there and been just enough larger to mostly make it intact to the ground instead of shattering up in the atmosphere.
scav
Wonder how long it will be before the data comes out.
bbleh
@scav: I’ve read variously about 12 hours minimum to get some sense of how the asteroid’s orbit was perturbed and “a few days” to get a fuller picture. I guess the only way they have to measure the orbit accurately is to time the passage in front of the larger asteroid, so they gotta wait for that to happen in a way we can see it, and it might take more than one orbit to really nail it down.
sab
@Baud: Still waiting for the Jetsons’ hovercraft they promised us. Not here yet, are they?
bbleh
@Another Scott: I read somewhere the current distance is about 8 light-seconds away, so that might explain the lag between the countdown and the imagery.
bbleh
@Ceci n est pas mon nym: I was surprised by how MANY frames there were, until I remembered the thing was going 4 miles a SECOND, so there was a lot of enlargement to do.
TriassicSands
First, that is quite different from there are no threats for the next ? years. The latest thing I read only went out to 2050. However, we haven’t identified everything, so there could be a more imminent threat. Also, perhaps much less likely, but still possible, would be something from outside the solar system — think ‘Oumuamua, but much, much bigger.
One virtual certainty? Something will eventually hit the planet with devastating results. Will there still be human beings at that point? Who knows, but probably not.
TriassicSands
Best case scenario? Despite scientists’ assurances Dimorphos is knocked out of its orbit and scores a direct hit on Mar-a-Lago (sometimes known as Moral Embargo) while “daddy” is home. If only.
Worst case scenario: The subsequent celebrations spread across the planet are so raucous they send the Earth crashing into the sun.
jnfr
@Martin:
That’s really well put.
I love space news. I’m glad we put resources into experimentation like this.
sab
@bbleh: Laugh all you want, but we olds already watch Matlock.
sab 🐕
Posting with filterproof emoiji. World is a wonderful place online. Rules dont even matter online. Glad I am off.
topclimber
@ColoradoGuy: Late to this dying world of a thread with a news flash: Tesla is working with warp drives.
Wait…I got that wrong. Make that warped drives.
kalakal
@SpaceUnit: We’ve understood that problem for a long time The Dynamics of an Asteroid* was published before 1888
* Sherlock Holmes ref
Ksmiami
@Goku (aka Amerikan Baka): I preferred Deep Impact. Still don’t understand the father-daughter wave scene tho
J R in WV
Sorry I missed the live coverage of the interplanetary attack! I’ll find the video later on. I definitely approve of research in planetary defense, and I’m older than Sab, probably. nearly 72 now. Had a CT scan a weeks ago, yesterday family practice Dr called me, first time he personally called to quiz me about pain in my hips, made an appointment with an orthopedic surgeon in two weeks. This is the same guy who replaced my shoulders and Wife’s knees, both well done jobs.
Then we went to Wife’s PT and picked up therapy diet for the cats, who are something like 17 y o. They have hypothroid issues, lost a lot of weight, Punkin could afford it, (was named for her shape, an oblate spheroid) has gained a lot back. Spike can’t afford it, still just under 6 pounds. Skinny as can be, but still purring on my shoulder most days. She’s been on a calendar, I forget the date… Stretched out grey kitty with big claws embedded in a small tree trunk.