I think it is good to know but from a technology perspective what would we do about it anyways?

I don’t know.. I mean I prefer that they focus on tracking the real big scary stuff… broken windows can always be repaired…

If you pick it up from far enough away, it wouldn't take much to knock an asteroid off course. Pop a nuke next to it and knock it off course by a degree, and it would miss us by 1000's of Km.

Apparently we need a swarm of defender rockets out there and hope it stays in friendly control.

[removed]

[removed]

NASA actually just tested this but not with a nuke, they launched a satellite at one at the impact caused a change in trajectory for both objects

[deleted]

Wouldn’t work, there is no air in space. Something would have to be attached to the asteroid or hit it in order to nudge it a bit.

“Beg your pardon Mr. President, but it’s a big-ass sky.”

[removed]

Close nuclear detonations would still push the asteroid simply by differential heating and vaporizing the rock on the facing side. Not much of a push, but it is one. Nukes might be the only recourse for rubble asteroids too. You'd have to have the warhead on a robot that would push itself inside before detonating for it to do any good, but I can't think of a better option.

[deleted]

This is true if close enough and it would need to be pretty close, space is big and that heat would dissipate rather quickly otherwise but still perhaps just enough to push it ever so slightly out of the way.

Yeah, it would have to be very close. The energy dissipates exponentially with distance. The more surface area exposed to the blast the asteroid has the more energy would be transferred though, so for really big ones it might be more effective than the basic chemical thrusters we have now. Not saying alot of course. A dinosaur killer has enough mass its debatable if we currently have the tech to deflect one that would hit within a decade or two.

[removed]

Until 1 of those rockets carrying the nuke fails and explodes... killing thousands.

Is it just me or does it seem like this happens quite a bit?

If we can discover an asteroid when it's nearing its apoapsis, it's slowest highest point in its orbit.. and if it can be predicted to be on course to impact Earth..and if we have a defensive impactor rocket somewhere out there on standby... and if we can get to the asteroid quick enough... it would only take a tiny little bump to knock it tens of thousands of kms off course. That's a lot of ifs.. but I think we're only a few decades away from having a somewhat effective chance at preventing an ELE.

Infinitesimal chance of rocket exploding that could never even set off the nuclear chain reaction, vs possible planet killing asteroid impact.🤔

My understanding is that the steam released from the flash boiling of water vapour in the rock would be enough to push an asteroid off course enough. As long as it was sufficiently far away.

How do we know there would be water on an asteroid headed for earth? Not all installer objects have liquids on them. How long would it take to deduce this and would this time be better spent trying other ways of deflecting it?

That’s an interesting idea about the robot. I’m wondering what others think about using:

https://en.m.wikipedia.org/wiki/Bunker_buster

There’s a section for nuclear, an adaptation of which, might be a realistic approach delivering a nuke deeper into an asteroid. Or a train of them, hitting the same point.

Edit: I love that you mentioned rubble asteroids btw, bc we might have a better chance at rendering those (relatively) safe. I’d be most concerned if the asteroid was a large chunk of iron perhaps. I doubt the bunker buster would have nearly the intended effect.

Unless it's was a solid metal of some kind, I believe it is a given that any rock based asteroid would have some level of moisture/ice in it.

From what I have read the rubble asteroids are the hardest to do something about. We can redirect a lump of iron provided we have enough warning, but rubble asteroids are much trickier since you cant just push them out of the way. The only two options are gravity tractor or demolition. Neither option is easy and both require lots more advanced warning compared to a similar mass solid asteroid.

Bunker busters wouldnt be particularly useful since the warhead wouldnt survive the impact at the speeds necessary to get sufficient penetration on a rubble asteroid big enough to need redirection. The drone idea is harder, but if you can get several deep enough with big enough bombs the blast should at least nudge the thing off course.

The budget to look for ELEs is still rather tiny. Which means the vast majority of telescope-time is ground-based, which means we can basically only look at the sky that's the half that is away from the sun. So anything that takes the trip through the inner solar system in under 1 year can easily sneak past our telescope efforts. We won't even be looking in its direction. Its the planetary version of a scary movie where the baddie walks up behind the character.

And even after the 1.2 billion dollar space based telescope that NASA is working on making, we will still be blind behind the sun and a few other narrow but many billions of directions on the sky (difficult to tell if a tiny light right next to a bright star or nebula is a rock, without massive computing power and individual light-spectrum analysis of every single light source on the night sky).

We likely won't have really good coverage before we get two or three or four such 1.2 billion dollar space telescopes going. Then they can take pictures with all of them directed at the same place at the same time and we'd only need to analyse pictures that differ between each telescope because everything outside our solar system has very low parallax.

Until then we're just holding our eyes closed on Earth going 67 000 miles per hour around the sun, hoping nothing hits us or vice versa. And the planet is a big gravity-well that sucks everything towards it.