Yes...we are waiting on the results.

When announced, you'll definitely hear about it ^(unless we've been taken out by an asteroid before then.)

DART was successful if we hit the rock and can make observations about how to improve a future similar maneuver.

Shouldn't this be a simple matter of physics, though? Like, wouldn't the mathematicians already have the answer?

Edit: I greatly appreciate the educational responses!

If there is a asteroid on a collision course with Earth, and it's big enough to cause some catastrophic damage, everyone on the planet will want some plan in action to make it go away. The simplest way to do that is to be able to do that is to alter the path of the asteroid ever so slightly that its course misses the Earth. Even though a satellite has very little mass, if you make it travel fast enough, you can impact enough velocity to give a big asteroid a nudge. Even if it's a tiny bit, that redirection propagating over millions of km will save the planet.

DART's mission target was actually a smaller space rock (roughly the size of the pyramid of Giza) that was orbiting a larger asteroid. Since they could easily detect the smaller rock's orbital period, they could calculate how much the impact would change its orbit. This would better inform scientists about what to expect from future redirect missions so that we could make a robust planetary defense system in case The Big One ever shows up.

They might do it again but bigger.

Essentially, they are saying that the test was successful but it is still only one data point.

The final aim of this research is to be able to know, in case an actually dangerous asteroid were on a collision trajectory with Earth, what kind of impact would be sufficient to knock it onto a safe course.

So we know the mass, trajectory and velocity of DART and soon we'll know the exact effect the impact had on Dimorphos, but what we don't know is the effect of Dimorphos's characteristics. What if DART had struck another asteroid with, for example, the same mass but denser? What if the asteroid had been composed of a different material?

By carefully analysing the impact site and the asteroid itself with follow-up missions (like HERA) we can try to determine the effect of Dimorphos's characteristics so that in the future we may more easily predict the effect of an impact on any asteroid, provided we have some data about it.

But what if it comes back?

Glad it wasn't just me that thought that. I'll go quitely now too...

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Good to know I'm not the only immature one on reddit.

Given the high-visibility of this expensive mission, NASA is likely being VERY careful how they will message findings to the public.

In other words, stay tuned.

Europeans are launching a follow up mission in 2023

A nuke in space would do less than you think. A nuke itself doesn't cause much impulse in a vacuum. It has inconsequential mass by itself, it just releases an immense amount of energy.

On Earth, we see a giant blast wave from a nuke. This is because it heats up matter(the atmosphere and ground around it), and that matter expands very quickly.

In a vacuum, you don't get that. It would heat up one side of the asteroid, which do to outgassing could alter it's course, and there is photon pressure. It's certainly been discussed. But I think at this point, especially with falling costs of mass to orbit, and kinetic impactor is a more viable option.

That is absolutely a great thought. People are responding to you saying that it's not the solution, but I had a discussion with someone working on DART who is a co-author of the paper this post is about. A nuke provides the greatest amount of energy per mass that can be delivered to an asteroid, so it absolutely is a 100% feasible option for planetary protection.

The largest issue with the nuke is the timing. DART impacted going roughly 6 kilometers per second. This means that a nuke would need to be timed within a few milliseconds of impact so it would be able to transfer energy to the asteroid without wasting it, but needs to be detonated before impact as the speed is so extreme if the spacecraft impacted the asteroid first the nuke would be destroyed without detonating.

Detonating a nuke in space is actually rather trivial though, the largest issue is navigating and guiding a spacecraft to the asteroid. DART was able to locate Didymos over a month out, but only was able to see Dimorphos a few hours before impact. Didymos is nearly 1,000 meters in diameter, Dimorphos is about 170 meters while the asteroids we are actually worried about are closer to 50 meters. Since they are smaller than we can detect from Earth, we would likely only discover it possibly weeks or months before impact, whereas something much larger would be discovered years earlier.

I have heard from people who worked on DART, that a potential DART-2 mission is a dry-run of nuking an asteroid without the actual nuke onboard, so that the design would already be finished if we discovered an asteroid with limited time before impacting Earth. That way they could re-build from existing designs, add the nuke and launch considerably faster in the case of an emergency.

Breaking it into multiple pieces/re-directing it both end up going together, at some point of pushing it you're going to break it up anyway because of the force required. One concern of breaking it up is that if it still impacted Earth, while it would be less likely to kill us all, it would have a high likelyhood of damaging many of our satellites in orbit. In 2014 a comet nearly hit Mars, and all the satellites (since there are not many around Mars) navigated to be on the opposite side of the planet to where it was likely to hit. Earth satellites wouldn't realistically have the same ability.

Why go all the way to nuking it if we can confirm crashing into at high speeds is an effective solution? A lot easier to plot a direct collision course than it is to time an explosion and/or make sure the device actually explodes on time.

Every answer telling you some supposed reason about why this is infeasible or ineffective is wrong. NASA and related, credible parties have conducted studies and generally conclude that a nuclear device is one of the most effective strategies we have of asteroid avoidance. The catch is that it would not be used in the manner you describe to "disintegrate" an asteroid - rather, it would most likely be detonated in a surface standoff detonation and use the vaporized surface as ejecta to propel the asteroid in the opposite direction.

https://web.archive.org/web/20160303220543/http://www.nasa.gov/pdf/171331main_NEO_report_march07.pdf

In the case of a large and/or imminent threat, this would likely be one of our only options. No other feasible strategy, whether kinetic impactor or gravity tractor, is capable of transferring so much energy to an asteroid in such a short amount of time. DART and the gravity tractor approach are both similarly mature technologies, but they require either for us to see the threat years in advance or for the threat to be very small - possibly both. A nuclear device is capable of redirecting a much larger asteroid with a much shorter notice.

There are technical challenges to address, yes, but relatively minor ones especially given the level of spaceflight technology we've already had for decades.

The obstacles right now are geopolitical, not technical. The Outer Space Treaty bans the use of nuclear weapons in space. That means we can't even test it. The DART II mission that /u/ItsMyImPulse mentioned would certainly be interesting, though - a dry run to confirm our technical ability to pull off a mission like this would do a lot for our preparedness in case we ever do need to actually do it, without violating the treaty.

We should just launch out supply of garbage at it instead

There's a treaty that says we can not use nukes in space.

I did some rough calculations of how much energy the DART craft had and it was about 1/1000 of the atomic bomb over Hiroshima. 1/1000 doesn’t sound like much but this was just an initial try. And that’s still equivalent to 15 tons of TNT. Not bad. The problem with a nuke is you can’t just slam it in, you first have to slow down, match speeds , then land and tunnel into the middle of it . Maybe all doable but dang .

Because a nuke would blast in all directions, losing most of the energy to space. Smacking into it at 14,000 mph directs almost all the energy directly into the asteroid. Much more effective.

There was a documentary that came out a while back that explained why nuking the surface of an asteroid wouldn’t do much to alter its course.

Why? You have the internet. Just go look up what the words mean.

It's all about how much energy we can transfer to the asteroid, and a spacecraft moving through space at 6.1km/s is carrying far more kinetic energy in its own velocity than it could ever carry in fuel. Crashing the spacecraft into the asteroid and transferring all of its own kinetic energy into it is way more efficient and economical than trying to land it, then use a thruster to steer it away.

Keep in mind we don't really need to "steer" it, we only need to nudge it in a general direction that we know will affect its orbit enough to miss Earth.

Additionally, any thruster we do use for such an application would likely have to be an ion engine of some sort, because otherwise the specific impulse of normal chemical rockets would be far too low. We'd have to send a ton of fuel to make any noticeable change to its orbit. However, ion engines provide barely any thrust and would take years, if not decades, to push the asteroid by any noticeable amount - which also means we'd need to notice years or decades in advance. Transferring all that energy in a single instant with a kinetic impact event is much better in that regard.

Only for asteroids we can predict collisions with well in advance.

The Asteroid Redirect mission that was supposed to happen a few years ago was cancelled due to lack of funding. DART is the replacement mission that was able to get funded.

Yes that is probably how we will do this next. But fat ion engine and some solar panels or maybe nuclear power station