Thumping small asteroids (DART).

[halfeye]

https://en.wikipedia.org/wiki/Double...direction_Test

It happened last night apparently. So far, besides the fact of the impact, the results appear to be unknown.

[Willie the Duck]

I'm suspecting it will take multiple measurements over quite some time before everyone feels they have solid data on the end-result trajectory. Especially since the asteroid (which may well not have been a contiguous piece to begin with) could have broken up and the final configuration and orientation of all the components are important to the findings.

[Sigako]

I expect some outcry from astrologers, because that's a modification of a celestial body path (not that they really track them). Although that would be a convenient scapegoat for their horoscopes not working...

As to the serious response: as far as I understand, this method is currently prohibitevely expensive. We really need cheaper space technologies.

[Telok]

Dimorphos is 5x10^9 kg orbiting another asteroid at about 12 hr orbit. They watch it with the same technique used to spot planets orbiting other suns, its that far away & small. Probe is 570 kg and expected to slow the orbit, contracting it, and reduce time by about 10 minutes. Most debris should be caught by the larger asteroid's (Didymos) gravity. Confirmation will take a week to a month, with some early results from a trailing cube sat taking pics of the event.

[sihnfahl]

as far as I understand, this method is currently prohibitevely expensive. We really need cheaper space technologies.

Obviously not prohibitively expensive, as they undertook it despite the costs.

They've shown it can work; they don't need to do another.

And it's only to be used in cases where the projected path intersects the Earth, while it's a significant distance away, and only if it's projected to cause a lot of damage. The number of times it would be used are so low that cost wouldn't be a factor.

Also, if you were stuck on tracks with a train approaching at high speed, how much would YOU pay for someone to get you off?

[InvisibleBison]

As to the serious response: as far as I understand, this method is currently prohibitevely expensive. We really need cheaper space technologies.

While cheaper space technologies would be nice, I don't think DART can be described as prohibitively expensive (assuming it worked, that is). The project cost $325 million, and subsequent ones would be cheaper, since some of that money was spent developing the spacecraft. That doesn't seem like an unreasonable price to prevent even a minor asteroid impact.

[pendell]

Incidentally, type in "dart space mission" into a google search on google.com or your chrome toolbar. See what happens

Respectfully,

Brian P.

[sihnfahl]

That doesn't seem like an unreasonable price to prevent even a minor asteroid impact.

And depending on where they project it to hit.

It'd be a waste for a minor asteroid to be deflected if it was going to hit the middle of the Pacific and just cause a few fish to go 'what was that!?'

If it was going to hit, say, Canberra... I'd say the Aussies would happily shell out for a mission.

All this talk also sparked a memory of mine of an old sci fi short story.

Astronomers find a massive asteroid. They do all the projections and find it's going to hit the Earth hard enough to effectively wipe out humanity. Story leaks, everyone freaks out. Riots in the streets, folks flooding the Churches, Synagogues, Mosques, shrines, etc. Standard End of Times stuff that leave cities ravaged, billions dead.

... the asteroid hits the moon.

[Sigako]

Obviously not prohibitively expensive, as they undertook it despite the costs.

They've shown it can work; they don't need to do another.

And it's only to be used in cases where the projected path intersects the Earth, while it's a significant distance away, and only if it's projected to cause a lot of damage. The number of times it would be used are so low that cost wouldn't be a factor.

Also, if you were stuck on tracks with a train approaching at high speed, how much would YOU pay for someone to get you off?

Proof of concept can be much more expensive than technology actually put to use.

And if I go homeless and starve after the 3rd train ditched - I think I'm doing something wrong.

That being said, rarity of need is a stronger argument. Also, I'm actually voting not for dropping the DART, but for making space technologies in general cheaper. On which they're already progressing, so well, let's give it 5-10 years to mature, I guess.

[Sigako]

And depending on where they project it to hit.

It'd be a waste for a minor asteroid to be deflected if it was going to hit the middle of the Pacific and just cause a few fish to go 'what was that!?'

If it was going to hit, say, Canberra... I'd say the Aussies would happily shell out for a mission.

All this talk also sparked a memory of mine of an old sci fi short story.

Astronomers find a massive asteroid. They do all the projections and find it's going to hit the Earth hard enough to effectively wipe out humanity. Story leaks, everyone freaks out. Riots in the streets, folks flooding the Churches, Synagogues, Mosques, shrines, etc. Standard End of Times stuff that leave cities ravaged, billions dead.

... the asteroid hits the moon.

There's a more obvious target nowadays, but I won't mention it lest I be banned.

And in actual story it hit Jupiter. Shoemaker-Levi-9, if I'm not mixing up unrelated events.

[sihnfahl]

And in actual story it hit Jupiter. Shoemaker-Levi-9, if I'm not mixing up unrelated events.

Unrelated event. SL9 was always predicted to impact Jupiter. What was remarkable about SL9 was that it had been theorized to have previously come within Jupiter's gravitational pull and got slingshotted, breaking into multiple pieces at the time. All the big pieces stayed in the same orbital pattern, so the impacts were spread across the outer layer of gasses.

Which, in turn, caused multiple plumes of interior gasses, so spectrographic analysis gave astronomers a 'peek' of those layers.

And the story predates SL9. Part of a compendium of sci fi stories I read in the 80s.

[Lord Torath]

Incidentally, type in "dart space mission" into a google search on google.com or your chrome toolbar. See what happens

Respectfully,

Brian P.

Amost as good as googling "askew"!

The asteroids/comets this program is designed to deflect are the sort that it doesn't really matter if it hits the ocean or the land, it's going to be catastrophic either way.

[sihnfahl]

The asteroids/comets this program is designed to deflect are the sort that it doesn't really matter if it hits the ocean or the land, it's going to be catastrophic either way.

IMO? If it's not world-ending, but still large enough to damage a significant amount of a city, they're launching the interceptor.

Consider the Tunguska event. It flattened 830 square miles or so.

Now imagine it happened not over Siberia, but over Moscow, a city with an area of 970 square miles.

[halfeye]

IMO? If it's not world-ending, but still large enough to damage a significant amount of a city, they're launching the interceptor.

Consider the Tunguska event. It flattened 830 square miles or so.

Now imagine it happened not over Siberia, but over Moscow, a city with an area of 970 square miles.

I don't know what the policy is, if there actually is one.

We can't predict the impact point of an incoming object until it's much closer than a DART target would be. A dinosaur killer would need to be hit, but if a much smaller one were coming, the odds against it hitting a city would be at least 100:1, maybe 10,000:1, so I'm not sure it should be redirected, if there were few possible missiles.

[Lord Torath]

Update! NASA says the impact worked to change the asteroid's velocity (and thus its orbit).
NASA DART Imagery Shows Changed Orbit of Target Asteroid

[Fat Rooster]

A 32 min reduction in orbit time. Definitely a major success.

Am I the only one bugged by them going on about the beta value beforehand, and not straight up saying what beta this result corresponds to? I can't find it anywhere. My guess is that the 73 seconds value was a smush, with beta of 1 (hard to see how it could be less), so this is maybe a 25? Anybody know better?

[Lord Torath]

Also, just because it seems appropriate:
xkcd