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tahanson43206

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Registered: 2018-04-27

Posts: 19,263

Planetary Defense - Asteroid Deflection - Asteroid Spin per Void

There may well be topics in the forum archive that are about asteroid dangers to Earth or Mars.

There were only two topics that contained the word "defense" and neither was about the danger of asteroids.

In another topic, Void just offered an idea that is interesting in it's own right.

However, I thought immediately of the asteroid deflection problem.

(th)

tahanson43206

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Registered: 2018-04-27

Posts: 19,263

Re: Planetary Defense - Asteroid Deflection - Asteroid Spin per Void

This new topic is inspired by another of many visions of Void:

http://newmars.com/forums/viewtopic.php … 44#p217644

It occurred to me that an asteroid that is headed for Earth might be given a spin (controlled of course) so that the components of the asteroid would be accelerated in desirable directions, as an alternative to the default collision with Earth.

Some clever engineering would be required, but the total amount of energy required might be comparable to what might be mustered for other approaches to the problem.

(th)

tahanson43206

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Registered: 2018-04-27

Posts: 19,263

Re: Planetary Defense - Asteroid Deflection - Asteroid Spin per Void

Apache Internal Server error objected to the text below:

In the post cited above, Void shows us how an asteroid might be spun up to send objects to other locations in the Solar System, using a tether similar to (but longer than) the one David used to give Goliath a headache.

(th)

tahanson43206

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Registered: 2018-04-27

Posts: 19,263

Re: Planetary Defense - Asteroid Deflection - Asteroid Spin per Void

The latest issue of Analog just arrived, and it contains an article about asteroid intercept that includes developments that may be new to one or two NewMars members. 

Happily, the article is published in full at the analog web site...

https://www.analogsf.com/current-issue/ … nate-view/

I will quote a bit of the article in hopes it will inspire a NewMars member to open the link.

THE ALTERNATE VIEW
Defending Against Killer Asteroids
by John G. Cramer

On Thursday, July 13, 2023, a sizable undetected asteroid (subsequently named “2023 NT1”) was headed for the Earth from the direction of the Sun and just missed a collision. It passed within ~100,000 kilometers, about three times further out than the orbits of geosynchronous satellites. Because the Sun is an astronomical blind spot, this very close encounter with near-Earth asteroid 2023 NT1 wasn’t discovered and tracked until two days after the near miss.

The asteroid is estimated to have a diameter of ~34 meters, a mass of ~52 kilotonnes, and a speed of 11.27 km/s. (Note: a metric tonne is 1,000 kg or 2,204.62 lb.) If asteroid 2023 NT1 had impacted the Earth’s surface, it would have liberated energy equivalent to ~1.5 megatonnes of TNT, about 100 times the energy as released by the Hiroshima bomb, and it could have caused very significant local damage.

(th)

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,263

Re: Planetary Defense - Asteroid Deflection - Asteroid Spin per Void

This post is about the ice injection asteroid mining concept originated by our Alaskan correspondent in the Knowledge forum.

There are several innovations to be attempted here, and I have some uncertainty about how well everything is going to work.

The link below is to a Google Document that is rendered in PDF format.
https://drive.google.com/file/d/1-z0UvZ … sp=sharing

If the link works, the file contains a conversation with Gemini in which two individuals participate.

The opening sequence was guided by the Alaskan, and I picked up the thread and carried it to a conclusion (of sorts)

The concluding sequence covers the use of the Moon as a suitable test environment for the Injected Ice harvesting method.

(th)

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,263

Re: Planetary Defense - Asteroid Deflection - Asteroid Spin per Void

In another topic, NewMars members have recently revisited the topic of a NASA experiment to impact a rubble pile asteroid.

This was a useful experiment in many respects, not least because it dramatically confirmed theoretical predictions by one or more NewMars members.

One of the outcomes of the discussion was the observation that the effectiveness of a gravity tractor is dependent almost entirely upon the mass of the tractor.   In discussion, it became clear that a useful strategy is to send a tractor to a rubble pile asteroid with an empty container to be filled with material from the rubble pile over time.  Small smart robots could pick and choose items from the surface of the rubble pile, and collect the material in the empty collection system.  That system might be one of Calliban's fabric bags, for example.  As the mass under control increases, two useful things occur...

First, the mass of the tractor increases.

Second, the mass of the rubble pile decreases.

At some point, the tractor will have the influence needed to guide the remaining rubble pile to a path that avoids an encounter with Earth.

It will be clear to NewMars members that a collection bag full of asteroid material would have significant economic value  in the right circumstances, so the asteroid deflection mission might pay for itself.

(th)