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NASA's DART spacecraft changed an asteroid's orbit around the sun

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Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#41

> slowed the orbit of a pair of asteroids around the sun by more than 10 micrometers per second Or in other words, 1 meter per day Why not say that?

Because the SI unit is meters per second, so maintaining the “second” gives people with that understanding a basis in which to compare the delta-V.

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#43

Earlier quoted context omitted.

You know what they say: the best planetary offense is a good asteroid redirect program It's also the best planetary terrorism, going by the plot of The Expanse

First things first, we have to colonize the rest of the solar system before we can terrorize Earth.

It depends on the size of the asteroid and precision with which it can be aimed...

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#44
post #23

Earlier quoted context omitted.

Inflammable made me so angry as a child/teen when I found out. I read it in our encyclopedia set but we didn't have a dictionary, and this was pre-internet. It was in the context of hydrogen and I could have sworn it was flammable. But here is this encyclopedia telling me it's INflammable. It's... not flammable? Looked it up in the school library. Thank you, that memory came up from the depths of time. Probably haven…

Exactly! The only logical way out of the flammable/inflammable mess is to use 'flammable' and 'non-inflammable', which makes me so mad.

It's just a parsing error. "in-" is also a prefix to create verbs from a name or another verb like inhume, inflame, induce, incite, inject, infiltrate. Inflammable is (inflame)-able and not in-(flammable)

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#45

Wild that we went from "can we even deflect an asteroid" to measurably changing a solar orbit. 150 milliseconds sounds tiny until you realize compounding over decades makes that a meaningful trajectory shift. The engineering confidence this gives for actual planetary defense is massive.

I find it mesmerizing how predictable orbital mechanics are. We can tell where celestial body will be years ahead with meter accuracy.

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#46

Earlier quoted context omitted.

You know what they say: the best planetary offense is a good asteroid redirect program It's also the best planetary terrorism, going by the plot of The Expanse

First things first, we have to colonize the rest of the solar system before we can terrorize Earth.

Why exactly? I think the US ought to spend a few trillion on an actual space battleship - one that never comes down to the surface, just sits in orbit. There was a project regarding dropping telephone pole sized pieces of metal from space as an offensive weapon - put something like that on the space battleship and...

That is simply "Assured Destruction" with absolutely no mutual drawbacks or lingering consequences like radioactive wasteland. Just craters.

This is also something where the 1st country to achieve the "Space Battleship" could effectively prevent any other from also doing so...

In theory, Bezos or Musk could do it.

I don't understand why any country would bother with ground based military assets at this point.

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#47

Wild that we went from "can we even deflect an asteroid" to measurably changing a solar orbit. 150 milliseconds sounds tiny until you realize compounding over decades makes that a meaningful trajectory shift. The engineering confidence this gives for actual planetary defense is massive.

Makes you wonder how many other objects were sent on new trajectories by even smaller influences

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#48
post #46

Earlier quoted context omitted.

First things first, we have to colonize the rest of the solar system before we can terrorize Earth.

Why exactly? I think the US ought to spend a few trillion on an actual space battleship - one that never comes down to the surface, just sits in orbit. There was a project regarding dropping telephone pole sized pieces of metal from space as an offensive weapon - put something like that on the space battleship and... That is simply "Assured Destruction" with absolutely no mutual drawbacks or lingering consequences li…

The technology doesn't exist and it would be a huge waste of money.

How heavy would a telephone pole sized tungsten rod be?

What happens when China, Russia, India or Pakistan find out you are building this (cause you can't hide it if it's in near earth orbit)? They would either knock it out of the sky or hit you with everything they have. We would do the exact same if anyone else was developing such a weapon.

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#49
post #46

Earlier quoted context omitted.

Why exactly? I think the US ought to spend a few trillion on an actual space battleship - one that never comes down to the surface, just sits in orbit. There was a project regarding dropping telephone pole sized pieces of metal from space as an offensive weapon - put something like that on the space battleship and... That is simply "Assured Destruction" with absolutely no mutual drawbacks or lingering consequences li…

The technology doesn't exist and it would be a huge waste of money. How heavy would a telephone pole sized tungsten rod be? What happens when China, Russia, India or Pakistan find out you are building this (cause you can't hide it if it's in near earth orbit)? They would either knock it out of the sky or hit you with everything they have. We would do the exact same if anyone else was developing such a weapon.

I personally would get whatever metal in space, so weight is not the issue - solving this problem would also create almost immediately chunks of rocks that could also be dropped. In all reality, anything can be "setup" to be a weapon - many ways have been identified here.

All required innovations - of which, most are not out of reach in the slightest, all of that tech would be immensely valuable, literally everything we do to secure space superiority will be actual gains - not smaller microchips equivalent innovations - entirely new machines, entirely new economies of scale - there is no equivalent military tech that we can develop on earth.

Not only is there really no conceivable way to ignore the strategic advantage once considered, the long-term economic payoff is actually reason enough alone to pursue the radical idea of a "space battleship" - I can think of about 20 ways to cause significant global issues with one measly space battleship.

As a hypothetical alone, it has reason enough to warrant a substantial amount of the 1.5 trillion defense budget the Pentagon plays with.

Re: NASA's DART spacecraft changed an asteroid's orbit around the sun

#50

> slowed the orbit of a pair of asteroids around the sun by more than 10 micrometers per second Or in other words, 1 meter per day Why not say that?

Because the SI unit is meters per second, so maintaining the “second” gives people with that understanding a basis in which to compare the delta-V.

One would think that any nerds that knowledgeable could divide by 86400 to make the article more accessible for the rest of us though.
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