DART Probe

[ysabetwordsmith]

NASA has finally gotten around to a concrete step toward the Umbrella: launching a satellite to crash into an asteroid with the intent of changing its orbit.  This is a great way to deflect Earth-threatening objects, if applied at long distance.  \o/

Comments

Re: Well ...

[ysabetwordsmith]

Hrm. Some people have said that an object could be broken down small enough to do no damage. This is difficult, but possible. The theory is that the pieces just need to be small enough to burn up in entry, rather than landing like bombs.

Your argument seems to imply that this would simply overheat the atmosphere into a firestorm. If so, that renders one option completely nonviable -- and there are plenty of people who think that "bomb it to gravel" is viable.

Re: Well ...

[siliconshaman]

NASA did the maths. If you bomb it to gravel, you end up setting the sky on fire basically.

A bomb at short range option only works if you can make a substantial proportion of the resulting gravel miss the planet... which is kind of the whole point anyway... or if you use a big enough nuke to vaporise a substantial percentage of the mass, which then dissipates into space due to thermal effects. (hot gas expands, imparting delta V in random directions etc.)

Although...what debris is left on a reentry trajectory is now very radioactive...

Re: Well ...

[ysabetwordsmith]

That is disturbing given how many people seem to consider fragmentation and/or nuclear explosion to be viable options.

It looks like deflection is the only good one, and that has to be done far away. We may not have that much warning. 0_o

Re: Well ...

[siliconshaman]

Thankfully, NASA has already figured all this out, and that why DART was launched. John Q public and the various congress-critters are still catching up, and Hollywood has a lot to answer for, but the people actually defending the planet are on the ball.

Which is one of the reasons why Arecibo II will end up being built... it was the only deep space radio telescope that could also act as a deep space radar, and gave us a much wider window of detection.

Re: Well ...

[ysabetwordsmith]

>> Thankfully, NASA has already figured all this out, and that why DART was launched. John Q public and the various congress-critters are still catching up, and Hollywood has a lot to answer for, but the people actually defending the planet are on the ball.<<

That would be more reassuring if NASA had more money and decision-making power. Politicians tend to be stupid, and they're the ones setting agendas and budgets.

>> Which is one of the reasons why Arecibo II will end up being built... it was the only deep space radio telescope that could also act as a deep space radar, and gave us a much wider window of detection.<<

I hope so. We urgently need that.