NASA scientists explain Asteroid Redirection Test plans

Speaker 1: I wanted to talk a little bit about why these asteroids were chosen for the dart mission. Um, first and foremost, these asteroids are not a threat to the earth. They're not a danger to the earth. They're not on a path to hit the earth in the foreseeable future that makes them appropriate target for a first test. But what really makes these asteroids ideal for this first is because it's a double asteroid system, just like the name of the mission says, there's two asteroids here. There's, Deimos the larger one. It's 780 meters [00:00:30] in diameter. And it has a small moon asteroid that goes around it. It's named demo. Morphos, it's 160 meters in diameter and telescopes on the earth have been looking at this double a system for decades because of the telescopes here on the earth. We know that the smaller demo mofos goes around. Speaker 1: Dynamos every 11 hours and 55 minutes just like clockwork. And we've been watching that for quite a while. So what dart is gonna do is it's gonna come speeding in really fast, 15,000 miles per hour, [00:01:00] and it's going to tie target onto DFOs the smaller of those two asteroids. Now darts also catch carrying Leche, a cube, which is a CubeSat contributed by the Italian space agency. It's kicked off 10 days in advance and it'll fly by after Dart's collision roughly three minutes and it'll take some spectacular images of the ejecta that will talk more about later. But now what we've done is the dart spacecraft is totally destroyed. Bleachy cube is long gone. How are we gonna know how much we deflected [00:01:30] this asteroid? Well, we're gonna use these same telescopes here on earth that have already been looking at this system for decades, and they're gonna turn their gaze back on this asteroid system. Speaker 1: So if you think about it, the dart spacecraft, the main body of it is about a hundred times smaller than DFOs the asteroid that it's targeting. So you can see this, isn't gonna destroy the asteroid. It's just gonna give it a small nudge. It's actually gonna deflect its path around the larger asteroid. So we're demonstrating asteroid deflection in this double [00:02:00] asteroid system. And it's actually just a small nudge. It's only gonna be a change of about 1% in that orbital period. So what was 11 hours and 55 minutes before might be 11 hours and 45 minutes or so, we're not sure that's one of the main measurements. And that's the goal for the dart mission here. Now, dart is all about testing this technology, doing this for asteroid deflection and, and importantly doing this first test now before we'd need it. If there was an asteroid that was [00:02:30] a threat to the earth, what you'd wanna do this technique would, would be many years in advance decades in advance, such that you would just give this asteroid a small nudge, which would add up to a big change in its future position. And then the asteroid in the earth, wouldn't be on the killer and using this double asteroid system to develop this capability, take this first step to being able to deflect asteroids in the future, um, is a, is a really a smart and a safe way to do this. First test. The dart mission is Speaker 2: About demonstrating [00:03:00] deflection of an asteroid, changing its course and doing it by hitting it with a spacecraft. So dart has to hit the spacecraft. The dart spacecraft has to hit the asteroid. Then dart has to measure the amount of deflection. And then we want to understand why that deflection came about how it works. So it's all about measuring the momentum transfer, how much momentum do we put into the [00:03:30] asteroid by hitting it with a dart spacecraft? And if one day an asteroid is discovered on a collision course with earth, then we have an idea of how big that asteroid is and how fast it's coming. And when it will hit that kind of information, then we will have an idea how much momentum we need to make that asteroid Misty earth. And so if you wanna do that with a can impactor, we also need to know how much momentum does a [00:04:00] kinetic impactor put into an asteroid. Speaker 2: So that's what dart will. That's what dart will tell us for the dart impact and to do that. We're going to be measuring in addition to the telescopic measurements of the orbit period, change of the Dimo system, we're going to be measuring with the cameras as we 'em into the, uh, target where we hit, what are the impact conditions? So what kind of terrain is it slowing? Are there boulders nearby? What kind of [00:04:30] terrain we hit? And then finally we'll have lit cube, take, take pictures of the impact and to measure the impact eject. So the cube is released by dart. It's just a little guy, it's a briefcase size asteroid, it'll fly by Dimo on its own. Then it will turn around and we'll take pictures of the dart impact of the ejecta. Um, we need to do this because the dart impact at 15,000 miles per hour, [00:05:00] that's going to black, tons of material, many tons of material off DFOs maybe thousands of tons. And we need to know how much material there is, how fast it's going and where it's headed. So with that information together, with the information from the dark cameras, where we hid and what the impact conditions were, that's what we'll use to determine the momentum transfer from the [00:05:30] dark impact. So lit cube is just such an exciting mission. It's the first deep space mission for the Italian space agency. What a way to start a program am it's unbelievable. I'm really excited. Thank.