There’s a Radical Plan to Cool the Earth With ... Moon Dust
It involves space cannons. And it’s 100 percent legit.
By Darren OrfPublished: Feb 10, 2023
- In an effort to keep Earth’s rising temperature in check, scientists are researching ways to artificially shield the planet from the sun’s radiation.
- Scientists from the University of Utah suggest that moon dust could be used to create a reflective “sunshield” around Earth.
- Although capable of reflective a significant amount of the sun’s radiation, the plan requires extensive lunar mining infrastructure and electromagnetic space cannons.
A long time ago (in every sense of the phrase), a Mars-sized celestial object named “Theia”
smacked into Earth and formed our moon. Now, 4.5 billion years later, scientists want to put that moon back to work by using its dust to cool down its fever-induced planetary neighbor.
Scientists from the University of Utah suggest that “ballistically eject[ing]” millions of pounds of lunar dust around Earth could help deflect the sun’s rays and cool down the planet. The idea follows similar
solar geoengineering concepts like ejecting reflected sulfur dioxide (SO2) into the stratosphere to gain the same sun-reflecting benefits (but with less potential health concerns).
However, this research is decidedly more sci-fi as it would likely require lunar infrastructure, electromagnetic cannons, and even orbital space platforms. The results of the study were published in the journal
PLOS Climate.
The idea comes from studying planetary formation in early star systems. During those chaotic days (technically millions of years) following the birth of a new star,
a lot of dust gets kicked up and surrounds the host star. If humans were able to artificially eject dust around Earth, creating what the researchers call a “sunshield,” it just might be enough to stave off 1 or 2 percent of the sun’s usual radiation—enough to forestall some of the worst effects of climate change.
“That was the seed of the idea,” Ben Bromley, astronomy professor and lead author of the study,
said in a statement. “If we took a small amount of material and put it on a special orbit between the Earth and the sun and broke it up, we could block out a lot of sunlight with a little amount of mass.”
The paper analyzes two approaches to injecting space dust. The first involves firing dust (things like salt or coal) from Earth to a way station at
Lagrange Point 1 (L1). Lagrange points are stable areas of space where the gravitational pull of two large masses equals the centripetal force needed for a small object to keep pace, which means much less fuel is needed to stay in position. Because of these stability benefits, important space missions like the James Webb Space Telescope are parked at Lagrange points (
L2, specifically).
However, dust isn’t quite the same thing as a
14,300-pound space telescope. Because of its incredibly light mass, dust is blown off these Lagrange points in only a few days thanks to solar winds, radiation, and gravity, so the dust would need to be consistently reapplied to maintain an effective sunshield. This makes continually launching dust from Earth’s surface a costly measure because of the planet’s gravity. Thankfully, the moon
also has tons of dust
and only 17 percent of Earth’s gravity—and that’s where scenario two comes in.
Using “
electromagnetic mass drivers” (aka space cannons), a large mining operation based on the moon could fire space dust to L1 much more affordably than launching dust from Earth. The only downside is the fixed cost of getting all the equipment to the moon in the first place, but the advantageous firing positioning from the moon means a way station at L1 may not be necessary at all.
Any effort to tackle climate change, whether trying to suck carbon out of the air, injecting SO2 into the upper atmosphere, or creating a lunar sunshield with electromagnetic cannons, must be in addition to humanity’s steady work to decarbonize all aspects of society.
But if you want to put electromagnetic space cannons on the moon, you’ll get no arguments from us.
My guess is that they are 30 somethings.
