Confirmed: Asteroid shoved by Earth crash probe DART NASA's DART spacecraft successfully smashed into asteroid Dimorphos with enough impact to alter the rock's orbit, scientists confirmed on Tuesday. Dimorphos, described as a moonlet, orbits larger asteroid Didymos more than 11 million kilometres (6.8 million miles) away from Earth. Before DART struck Dimorphos on September 26, …
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"By gathering data close-up, Hera will help turn DART’s grand scale impact experiment into a well-understood and repeatable deflection technique."
https://www.esa.int/Space_Safety/Hera/Planetary_defenders_after_NASA_s_DART_comes_ESA_s_Hera
https://www.heramission.space/
https://en.wikipedia.org/wiki/Hera_(space_mission)
You're thinking of LICIAcube. The first pictures have been downloaded but it's a slow process and only a few of them have been released at this time
(https://www.nasa.gov/feature/first-images-from-italian-space-agency-s-liciacube-satellite). Due to the small size of the cubesat and the distance involved, downlink speeds are very low and it'll take a few more weeks to get all the data back.
NASA's APOD recently showed a video: https://apod.nasa.gov/apod/ap221005.html
"Explanation: What happens if you crash a spaceship into an asteroid? In the case of NASA's DART spaceship and the small asteroid Dimorphos, as happened last week, you get quite a plume. The goal of the planned impact was planetary protection -- to show that the path of an asteroid can be slightly altered, so that, if done right, a big space rock will miss the Earth. The high brightness of the plume, though, was unexpected by many, and what it means remains a topic of research. One possibility is that 170-meter wide Dimorphos is primarily a rubble pile asteroid and the collision dispersed some of the rubble in the pile. The featured time-lapse video covers about 20 minutes and was taken from the Les Makes Observatory on France's Reunion Island, off the southeast coast of southern Africa. One of many Earth-based observatories following the impact, the initial dot is primarily Dimorphos's larger companion: asteroid Didymos. Most recently, images show that the Didymos - Dimorphos system has developed comet-like tails."
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"I think. I am neither a mathematician, nor an astrophysicist."
But every second counts! 18 seconds at the speed of light is 3.348 million miles which is a lot more margin for error than I'm comfortable with. Then again at that speed it's all relative. I'm no physicist either, and certainly no Einstein.
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It's not even an 18 second change on the orbit of 770 days I think as most of the velocity change of dimorphos is it's orbital velocity around the parent body, for the total system I think that only equates to a small change in angular velocity so likely it'll only change the rotational speed or wobble of Didymos. It's orbital period is probably less affected.
Err, no.
The change is referring to the orbital period of the Didymos / Dimorphos system. They both orbit a common centre of mass with the same orbital period, which just reduced by 32 minutes.
The orbital velocity of Didymos (relative to their common centre of mass) will have changed by 1/104 of that of the change of orbital velocity of Dimorphos, because it's more massive and closer to the system's common centre of mass.
I'd be interested to know what the change of the orbit of the Didymos / Dimorphos system around the Sun is, but that wasn't the objective of the mission and will take a much longer observation time.
According to wikipedia, the two bodies were tidally locked. I imagine that lock has been broken (somewhat), and the eccentricity of their orbit also changed. This is surely worth investigating up close for an extended period of time, to learn something about how binary asteroid systems, and contact binaries, come to be.
> Warning time is really key here in order to enable this sort of asteroid deflection
Great, but given our currently rather limited means of detection, we can only hope detecting any potential hazard early enough (years!) to do something about it. Detection needs to get an upgrade if we don't want to go the way of the dinosaurs.
Figuratively speaking, yes, I know about "Kentucky Fried Dinosaurs"™.
Even acknowledging the existence of "Kentucky Fried Dinosaurs"™, I would argue that "going the way of the dinosaurs" is still a fate to be avoided.
Imagine either the corvids getting their own back, or the cephalopods filling the gap and having "Kentucky Fried Primate" on the menu.
> First time humanity has successfully shifted the orbit of an astronomical object
Not quite. Any time a spacecraft has availed of a gravity assist slingshot around another planet, that body has slowed down in accordance with Newton's Third Law. Although to paraphrase Arthur C. Clarke, it'll be a long time before humanity has instruments sensitive enough to measure such a change.
Also "Deep Impact", the NASA mission to study the internals of Comet Tempel 1: https://solarsystem.nasa.gov/missions/deep-impact-epoxi/in-depth/
"The primary mission of NASA's Deep Impact was to probe beneath the surface of a comet. The spacecraft delivered a special impactor into the path of Tempel 1 to reveal never-before-seen materials and provide clues about the internal composition and structure of a comet."
The problem with that approach is that you need to bring along an enormous boatload of fuel to slow down and then move the object. Whereas due to the wonders of the Oberth effect it's possible to impart a lot more kinetic energy into your spacecraft for the fuel burned.
There is also the problem that most of these space rocks aren't really hard rocks but more like giant gravel piles floating through space. There was even some worry that Dimorphos might have been too loosely bound for the impact to work and that the probe might just blow straight through. Certainly if you were to attempt a "land and push" approach you'd have to take into account that you need a lot of surface area to avoid the probe from burying itself deep into the surface potentially damaging itself in the process. Alternatively it's been proposed that doing so on purpose might allow the probe to fire a lot of surface material along with the exhaust gas of the thruster, increasing it's impulse and making it more effective, but if we're talking a (very near) earth impactor then this might just result in a long term hail of smaller rocks raining down into our planets atmosphere. Potentially (slightly) better than one huge big honking one, but certainly not going to be enjoyable.
Another issue with 'land and push' is that all astronomical objects are spinning. The Earth rotates once every 23 hours and 56 minutes on an axis that wobbles slightly. Asteroids similarly can have quite complicated rotational motion. So co-ordinating the pushing with the rotation would be crucial and much more complicated than simply crashing.
Nonsense! You both forget movie physics basics: Spaceships don't need fuel (no fictional spaceship I've seen had enough fuel capacity to even fly from New York to Los Angeles), alien planets/asteroids/whatevers' surfaces are as hard as any studio floor can be, and all stellar bodies only move when it's convenient, the rest of the time they stay put, allowing for easy targeting and navigating.
So, the dropping of a tiny cubesat with a huge nozzle extension (to look badass) which unfolds into a huge engine and pushes the asteroid out of our solar system is totally credible. I'm sure ACME Corporation sells some.
Aaarrrggghhhhh!!!!!!
You're correct, movie physics 101: just point your spacecraft at the orbiting object you want to get to, and 'hit the go stud' and you'll get there. Because orbital mechanics is exactly like driving a car*.
movie physics 102: All interstellar spaceships power life support systems for the the entire journey, even though the entire human population and living cargo is in deep hibernation**.
movie physics 103: you get 'gravitational attraction' everywhere in your spaceship, despite actually having to use a centrifuge for the crew quarters and exercise area***
Oh well, I'll just mumble to myself from now on.
*SPOILER ALERT - 'Gravity' with George Clooney.
**SPOILER ALERT - 'Passengers' with one of the Chris's (Pratt, Pine, Rock, they all look the same to me ;o) )
***SPOILER ALERT - '2001 - A Space Odyssey' (There is gravity in the pod bay when Dave and the other astronaut discuss de-commissioning HAL, but it cannot be part of the centrifuge system as it has external doors).
That's the one with Talkie Toaster - the episode is White Hole (wiki link)
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