NASA's DART spacecraft changed an asteroid's orbit around the sun
33 points
3 days ago
| 7 comments
| sciencenews.org
| HN
gatreddi
9 minutes ago
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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.
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prism56
2 hours ago
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Interesting. I'd not considered the loss of mass as a means of propulsion.

Obviously there was the kinetic energy transfer but the impact ejacted some of the asteroids mass opposite to it's trajectory further increasing it's trajectory change.

Cool demonstration, hopefully not needed one day.

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messe
2 hours ago
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That's how rockets work.
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prism56
2 hours ago
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Yeah, I sort of meant in the context of an object losing its mass, it's seldom used on earth as the effects are small but on the timescale/distance/speeds of an asteroid it could have noticeable effects.

Rockets are using mass loss but there's more going on with the rapidly expanding gas causing the increased impulse.

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yubainu
1 hour ago
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That's interesting news. I wonder how much kinetic energy it had. This accumulation of information might be useful if an asteroid were to hit the Earth someday. At the very least, it's more realistic than sending oil drilling experts to an asteroid.
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willis936
35 minutes ago
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>it's more realistic than sending oil drilling experts to an asteroid

Mandatory sharing of Ben Afleck commentary speaking for all of us.

https://youtu.be/-ahtp0sjA5U

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NooneAtAll3
21 minutes ago
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I'm annoyed at these nothing-burger titles...

Instead of pointing out that exact measurements finally came in (of long term movement change), journalist instead focused on the obvious outcome that everyone expects and knows

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wartywhoa23
1 hour ago
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Well done, DART, which country did you aim it to?
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zeusdclxvi
15 minutes ago
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India
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hulitu
32 minutes ago
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> NASA's DART spacecraft changed an asteroid's orbit around the sun

Captain Obvious strikes again. Is school so low quality, that someone has to write a news article about it and somebody else thinks this is worth posting on a technical forum ?

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p0w3n3d
2 hours ago
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Wow, that's the first step!

However, the most efficient method would be actually land (I know - maybe even impossible?) on it, and use propellers to change its trajectory. We don't have too much throwaway high-tech to crash it on asteroids...

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XYen0n
1 hour ago
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Impact is actually a more efficient method, as it avoids the fuel consumption required for deceleration and soft landings.
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Incipient
2 hours ago
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I'm not sure this is actually a necessary explanation...but while propellers technically COULD function in space (not a perfect vacuum, right?)...they're basically going to be useless.
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Rexxar
1 hour ago
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He probably misuses "propeller" which is strangely restrictive to "rotative blade propulsion" in English whereas "to propel" is generic in its meaning.
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