Could we Terraform the Moon? From the writer of The Terraformers’ Toolkit. (The Terraformers’ Toolkit: Everything you have ever wanted to know about terraforming and our future in space. The where, why, when, how and what of terraforming.) www.amazon.co....
Proximity
Our Moon is right next door and our closest neighbour in space. However, it sits at the bottom of a gravity well, which means that spacecraft will require a lot of fuel to land and to take off as getting to the surface of the Moon from low Earth orbit or back would need a velocity of 6 kilometres (3.7 miles) per second. However, the Moon has real estate and lots of it very close to Earth. Thus, the objective may be to get to the Moon because of its proximity rather than resources or as a stopping off point on route to anywhere else.
Resources
The moon is very poor in some of the elements that we need to survive, such as carbon, nitrogen and hydrogen. There is oxygen, but it is tightly bound in combination with other elements. It can be extracted, but requires high temperatures to get it out. There are metals, principally titanium, which have been implanted into ilmenite by asteroids, comets and the solar wind. Most of the other metals have sunk into the Moon’s core.
Transport
Are there any other ways to get between the Moon’s surface and lunar orbit? Linear motors or mass drivers could be used to propel buckets full of regolith into lunar orbit. Alternatively electrical catapults could be used to put material into Lunar orbit.
Another device which could get mass into orbit is a space elevator or skyhook. This would use an asteroid in geosynchronous orbit about the moon, with a long cable reaching to the surface and another into space in the opposite direction. Then when the system has been proved to be stable, elevator cabs could ascend and descend to get people and goods into space or back to the lunar surface.
So, the fuel requirement of getting to the Moon’s surface or back into space might not necessarily be a complete deal breaker.
Bases
Radiation will be a big health issue, but a covering of lunar regolith should provide sufficient protection. A 20-ton lunar base would need to be covered with between 100 and 500 tons of regolith shielding. Alternatively bases could be underground or protected by 10 centimetre-thick (4 inches) glass domes to shield the occupants against solar flares and cosmic radiation.
The moon experiences solar flares and extreme temperature variations, and temperatures are only stable in polar craters.
The Poles would be the best places for base because they have permanently shadowed craters with water ice, and constantly illuminated highlands for solar energy. Together this means that rocket propellant and fuel for lunar excursion vehicles could be manufactured from local water and solar energy collected in the highlands and beamed to the base using radio waves.
Dust
The Moon’s low gravity also makes it hard to excavate with the same kind of equipment that we use on Earth. Lunar dust could easily be hoisted into Lunar orbit, it is extremely abrasive and electrically charged, so it could damage equipment and harm people. Lunar dust is known to cause vision impairment, instrument inaccuracies, machinery breakdown, traction loss, abrasion, thermal control issues, seal failures and inhalation illnesses.
Terraforming
Lunar colonies could be expanded into a ‘shell world’ in which a spherical shell could be constructed right around the moon within which Earth-like conditions would be maintained. This shell could protect the occupants from radiation, maintain comfortable temperatures and air pressures and provide artificial lighting. It could dehumidify the air, and let the collected water fall as rain.
Days and nights
Another problem for any Moon base is that both days and nights last a full two weeks (336 hour) each. The moon could be spun up using impacting volatile rich asteroids. However, the Moon is not perfectly spherical; it actually has a tidal bulge facing Earth. Therefore, a spinning Moon would be affected by Earth’s gravitational pull, which would generate a torque that could eventually bring the Moon back to tidal locking with the same side always facing earth.
The solution to both radiation and day length may be to build a shell around the whole of the moon. The underside of this could be used to project the sun and stars, and simulate days and nights, and the shell could protect the surface against radiation. This is probably the best long term solution, and would allow the moon’s climate and living conditions to be controlled. It would not fix the mineral deficiencies though, and carbon, nitrogen and hydrogen would still need to be brought in from elsewhere.
26 авг 2024