3 ms·
How can it works? The moon is already huge and when it’s eclipsing the sun it’s only shading a small spot. One would need to block a significant fraction of th
by bobim 3y ago
How can it works? The moon is already huge and when it’s eclipsing the sun it’s only shading a small spot.
One would need to block a significant fraction of the solid angle between the sun and earth. The smallest side is on earth side, and that would require an object the size of the planet.
Looks like we’re hanging on anything to procrastinate the mandatory society shift.
- ianburrell 3y agoThe shade would be much closer to the Earth than the Moon. The article says shade would block 2% of Sun light. It would "would have to be about a million square miles, roughly the size of Argentina".
- bobim 3y ago2% is about the ratio of earth cross section area to Argentina surface, that sums up. Proximity should not impact the efficiency as the Sun is not a point source and what is important is effectively the ratio of lit/shaded surface. Now that’s 2.8 millions of square km that is 2.8e12 square meters. Mylar at 7g per square meter would mean sending up 19.6e6 tons for the sail only. Low orbit future best payload seems to be 250 tons, the sail would then take about 8000 rocket launches if I’m correct. And then the sail’s structure, moving it to high orbit, the steering system to manage the tremendous solar pressure, etc…