The wild concept was put forward by a group of astrophysicists in a study published Wednesday in PLOS Climate. Benjamin Bromley, Sameer Khan, and Scott Kenyon theorized that a solar shield could be created to deflect the sun's rays from Earth.
Coal and sea salt were considered as materials that could be used in the shield, helping to dim the sun by as much as 2%, or around six days of sunlight per year, thereby lowering the Earth's temperature. But lunar dust turned out to be the ideal candidate as it is just the right size and composition for efficiently scattering sunlight away from our planet, said Bromley.
Another advantage of moon dust is that it would take much less energy to launch it from the lunar surface compared to earth-based launches, though it would still require an estimated 22 billion pounds of dust to be mined and loaded into a ballistic device such as a rail gun and fired. This would need to be performed regularly to maintain the shield as the dust would slowly disperse. An abrupt halt in the cooling of the earth could caused "termination shock," in which the planet rapidly heats up, writes The Guardian.
[...] The proposal isn't the first time someone has suggested using a physical object in space to address global warming. A 1,250-mile glass shield, trillions of spacecraft sporting umbrella-like shields, blasting dust off an asteroid, a raft of thin-film silicon bubbles, and space mirrors are some of the other space-based suggestions. There was also the space shield in the magnificently awful Highlander 2.
[...] "Nothing should distract us from reducing greenhouse gas emissions here on Earth," said Bromley. "Our strategy may just be a moonshot, but we should explore all possibilities, in case we need more time to do the work here at home."
Journal Reference:
Bromley BC, Khan SH, Kenyon SJ (2023) Dust as a solar shield. PLOS Clim 2(2): e0000133. https://doi.org/10.1371/journal.pclm.0000133
(Score: 5, Insightful) by JoeMerchant on Sunday February 12, @08:37PM (4 children)
If they are launching the dust in what would be a temporary ring, something that would "turn itself off" within 5-10 years, or less (recaptured to the lunar surface), this might be less than 100% batshit crazy. Oops we didn't think of _that_, sorry about the Snowball Earth for the next 5000 years isn't a good possibly future.
Of course, a cloud that would get recaptured by lunar gravity would be a belt-shadow near the equator, which should do all kinds of whackadoodle things to global weather patterns, not to mention screwing up just about every major ecosystem on land and most of them in the oceans.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by Reziac on Monday February 13, @03:33AM (3 children)
Someone elsewhere mentioned that breathing this stuff would be the equivalent of putting the entire world on an asbestos inhaler.
This isn't an experiment you can recall or halt if it goes wrong, And I recall a paper from some years back that noted just 2C worth of cooling could throw the Earth into a permanent ice age.
And there is no Alkibiades to come back and save us from ourselves.
(Score: 2) by JoeMerchant on Monday February 13, @10:44AM (2 children)
If we are setup with enough energy to launch dust to orbit, it wouldn't be much more energy to melt the dust into rounder shapes prior to launch. Personally, I would rather launch larger, potentially individually trackable objects than dust.
And, as for over-cooling, absolutely... This would have to be a two way adjustable thing, that's a big part of our problem already is our inability to turn down the greenhouse gas emissions (unlike freon.)
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by Reziac on Monday February 13, @03:16PM (1 child)
Know what's the only significant "greenhouse gas" ??
Water vapor.
Other elements in the atmosphere barely rise to the margin of error.
Also, if you have not seen "A Dearth of Carbon" -- an interview with Sir Patrick Moore (co-founder of Greenpeace) -- it's an eye-opener.
And there is no Alkibiades to come back and save us from ourselves.
(Score: 2) by JoeMerchant on Monday February 13, @05:35PM
>barely rise to the margin of error.
Welp, that margin of error has tracked with average temperature rise for some time now. Whether it's water vapor, cow farts, or fairy dust, I'd rather have a functional climate control knob than not have one - based on the historical record the holocene is rare, and worth protecting.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 5, Insightful) by Spamalope on Sunday February 12, @09:27PM (3 children)
I'm sure a cloud of dust with nice tooth would do wonders for sandblasting solar panels, imaging cameras and sensors.
Of course, it'll be perfect and no small orbital speed rocks will be in the mix with the dust, right?
We've also got a perfect record of predicting *exactly* what the climate change will be. No way that could go wrong, right?
What about nuclear winter, for the environment! (assume snarky comment about escalation in Ukraine really being green!) A bit more snark plus pointing out caution is warranted when it comes to yellow journalism - Global cooling used to be the 'pass the legislation that enriches my buddies' club along with Nulcear Winter (grifters get involved in any hysteria, now it'll be climate/carbon credits etc)
http://img.timeinc.net/time/magazine/archive/covers/1979/1101791224_400.jpg [timeinc.net]
All that said, I'm for developing the rocket tech you'd need to actually do this but against doing something that adds more space junk in orbit of any kind. (might be you could do something in very low orbit, that could be a temp test but... trust would have to be earned)
(Score: 3, Interesting) by JoeMerchant on Sunday February 12, @11:12PM
>I'm sure a cloud of dust with nice tooth would do wonders for sandblasting solar panels, imaging cameras and sensors.
Good points. Counter points: take it a little slower and melt the regolith into controlled sized smooth spherical rocks, I'm thinking the bigger the better for later cleanup because it's not like a bb sized pellet moving at 20kmph relative velocity is going to be easy to shield against... Chuck these basketballs into single orbit where they crash back on the lunar surface after a few months or maybe even a year or two, preferably in a few tight crash zones so you can possibly trundle out and retrieve them for relaunch, or if not at least keep the pattern predictable.
The key is a fully robotic process where you produce one new launcher chain per year or so until you have the shade needed.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by Reziac on Monday February 13, @03:36AM
Where I lived in the SoCal desert, the lifespan of plexiglas on the downwind side of a building was about 3 years due to blowing dust, and we didn't really have a lot compared to most dry areas. It also etched windshields and other glass, tho that took longer.
And there is no Alkibiades to come back and save us from ourselves.
(Score: 2) by DannyB on Monday February 13, @07:40PM
The worst part of this idea is that you can't undo it if it turns out to be any single one of the bad things predicted in the comments on this page.
Orbital speed collisions with dust and microscopic debris. Over-cooling the planet, like nuclear winter. (Of course, this will give a boost to the coal fired power plants, so they will lobby for this.)
How could this possibly be un-done, once it is done?
Hey, let's make both orbital space AND earth useless in one small step for mankind!
How often should I have my memory checked? I used to know but...
(Score: 2, Troll) by Anonymous Coward on Sunday February 12, @10:27PM (2 children)
Gotta make the sale, any way we can. Every "crisis" is an opportunity.
(Score: 1) by dg on Sunday February 12, @10:41PM
(Score: 0) by Anonymous Coward on Monday February 13, @07:26PM
Troll
Guess I was modded by a couple of... opportunists
(Score: 1) by Runaway1956 on Sunday February 12, @11:58PM (1 child)
Get it out of moon orbit. Get it entirely out of earth orbit. Put a cargo of dust between the earth and the sun, in a solar orbit. Park a load of it a million miles or more sunward, and release the dust with a very small impetus, so that it spreads in the vicinity.
No, it won't exactly match earth orbit, but putting many loads into that orbit is going to decrease the amount of sunlight hitting the earth.
I suppose there's no turning that off though. Sure, it will disperse over time, but, who knows how long that would take? Let's launch a few thousand loads to find out!
Abortion is the number one killed of children in the United States.
(Score: 2) by JoeMerchant on Monday February 13, @12:44AM
A bit more energy intense, and probably requires more than one delta-v operation to get it on station for a reasonable time period.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by progo on Monday February 13, @12:34AM (2 children)
This sounds like a very bad idea.
(Score: 5, Insightful) by BsAtHome on Monday February 13, @01:00AM (1 child)
Not only does it sound like a bad idea, it is a very bad idea
(Score: 0) by Anonymous Coward on Monday February 13, @12:24PM
Is this like The Flash breaking the Universe level Bad Idea just so they can replace characters with people of darker skin colors?
(Score: 3, Interesting) by Username on Monday February 13, @09:48AM (2 children)
I like my planet just how it is, habitable. No need to fix it when it isn't broken.
We'll never have the resources or tech to do this, but if we did, we should do it to a planet that isn't habitable, like venus.
(Score: 0) by Anonymous Coward on Monday February 13, @12:35PM (1 child)
Wrong way to look at it. They are saying the planet is broken and we need to fix it.
(Score: 1, Troll) by Reziac on Monday February 13, @03:18PM
And they assume that 1) they are the only source of wisdom, and 2) they are infallible.
This isn't science, it's a death cult.
And there is no Alkibiades to come back and save us from ourselves.