Alpha Centauri 2

Community => Recreation Commons => Destination: Alpha Centauri => Topic started by: Unorthodox on October 12, 2022, 01:57:34 AM

Title: Asteroid's path altered in NASA's first test of planetary defense system
Post by: Unorthodox on October 12, 2022, 01:57:34 AM

https://www.reuters.com/lifestyle/science/nasa-says-dart-mission-succeeded-altering-asteroids-trajectory-2022-10-11/?utm_source=reddit.com

Quote

A Dimorphos-sized asteroid, while not capable of posing a planet-wide threat, could level a major city with a direct hit.

Scientists had predicted the DART impact would shorten Dimorphos' orbital path by at least 10 minutes but would have considered a change as small as 73 seconds a success. So the actual change of more than a half hour, with a margin of uncertainty plus or minus two minutes, exceeded expectations.

The relatively loose composition of rubble that Dimorphos appears to consist of may be a factor in how much the asteroid was budged by DART's blow.

So proof the squishy rubble pile type does transfer energy better as BU theorized. 

So...now we need to target a hard asteroid and compare, or figure out if/how to tell the difference. 

Title: Re: Asteroid's path altered in NASA's first test of planetary defense system
Post by: Geo on October 12, 2022, 07:49:49 AM

In that case, a mission to 433 Eros might prove conclusive.  ;cute

Title: Re: Asteroid's path altered in NASA's first test of planetary defense system
Post by: Unorthodox on October 12, 2022, 05:57:45 PM

Exactly my kind of point, it took a mission to Eros it to prove exactly what it was, and that mission found we had estimated things pretty poorly at the time.  For a potential redirect mission, we kinda need to know before. 

But, no, Eros is really not a good candidate to compare for a crash test.  It's quite a bit larger and harder to measure the change. 

Title: Re: Asteroid's path altered in NASA's first test of planetary defense system
Post by: Geo on October 13, 2022, 04:29:40 AM

Not if you use a more massive (or faster) DART...

Title: Re: Asteroid's path altered in NASA's first test of planetary defense system
Post by: Unorthodox on October 13, 2022, 12:59:11 PM

The point I'm trying to make is we seem to be fairly bad at estimating the size and composition of objects at the moment, which is needed to know what size and speed of object we need to send. 

Our estimate of Eros' mass was off ~ 30%. 

Our estimate of how much we'd move Dimorphos was ~10 seconds, it moved it over 30 seconds.  They're crediting the loose surface for at least part of that discrepancy. 

Determining whether surface composition truly accounts for the entire discrepancy on Dimorphos by slamming a similarly sized 'hard' target seems a logical step. 

I'd also like to see landing a booster and firing an engine re-direct mission. 

Title: Re: Asteroid's path altered in NASA's first test of planetary defense system
Post by: Geo on October 13, 2022, 02:46:20 PM

Quote from: Unorthodox on October 13, 2022, 12:59:11 PM

The point I'm trying to make is we seem to be fairly bad at estimating the size and composition of objects at the moment, which is needed to know what size and speed of object we need to send.

Oh, I agree. Or, I would say, astronomists are bad at making a sufficiently exact estimation of size/composition from a distance.
Get the right equipment close enough and they're golden.

Quote from: Unorthodox on October 13, 2022, 12:59:11 PM

I'd also like to see landing a booster and firing an engine re-direct mission.

It definitely is feasable, with the Dawn probe's propulsion system