Terraforming the Moon by Comet

In my last blog post, I discussed the passed in David A. Hardy’s book, Atlas of the Solar System, in which he described the possible methods which might be used in the future to transform Mercury, Venus, the Moon and Mars into worlds, where humans and other creatures could live in the open, instead of the enclosed environments they need now to protect them from the harsh conditions of space. In the case of Venus, comets would be used to increase the planet’s rotation from its current 224 Earth days to a terrestrial day, and give the planet water. Looking through YouTube, I found this video by Fraser Cain, in which he talks about using the same method to terraform the Moon, as suggested by the space scientist and SF writer, Gregory Benford. This is part of a series of videos on space and space colonisation. At the beginning of the video, he mentions a previous one about the terraforming of Venus.

The explanatory section on the YouTube page provides this transcript of his talk.

In our episode about terraforming Venus, we talked about cooling the planet with a giant sunshade, and then hand-wavingly bind up all that carbon dioxide.

We did the same with Mars, filling the atmosphere with greenhouse gasses to warm it up, and releasing the planet’s vast stores of C02 to thicken the atmosphere. Then just crash in a few comets worth of water and upgrade them to to a 3 star resort.

We’re pitching this as a new series on the Discovery Network, called “Flip My Planet – Canada”.

Now let’s turn our imagination towards another rockball that is really more of a fixer-upper: The Moon. I know, you never even thought of the Moon as a place that we could possibly terra-renovate. Go ahead and imagine with me all the possibilities of a verdant green and blue little world hanging in the night sky. Doesn’t that sound great?

So, what does it take? Do we tear it down and just use the orbital lot space? Should we raise it up and lay a new foundation? Or could we get away with a few coats of paint and adding an atrium on the backside?

Fortunately for me, scientist and sci-fi author Gregory “Planetary Makeover” Benford has already done the math.

Let’s take a look at what we’d need to get the Moon habitable. For starters, the fact that the Moon is so close to Earth is a huge advantage. This is like living on the same block as a Home Depot, and we won’t have to travel far to get supplies and equipment to and from our project.

We’re going to need an atmosphere thick enough to breathe and trap in the Sun’s heat. This takes wild comet capture and harvest, tear them apart and smash them into the Moon.

Benford notes that you probably want be careful not to let an entire comet collide with the Moon because it might spray your primary investment home with debris and do a little damage to the resale value, or potentially annoy your tenants.

This could get bad enough that we’d have to terraform Earth to get it livable again, and you’d need to bring in Mike Holmes to publicly shame us and put our primary residence back in order.

After you’d splattered a few comets on the Moon, it would have an atmosphere almost immediately. The transfer of momentum from the comet chunks would get the Moon rotating more rapidly.

If you invest a little more in your planning stage, you could get the Moon spinning once every 24 hours, and even tilt its axis to get seasons. Benford estimates that we’d need 100 Halley’s mass comets to get the job done. This might sound like a pretty tall order, but it’s tiny compared to number of comets we’d need for your Mars or Venus real estate scheme.

The maintenance and upkeep isn’t going to be without its challenges. Low gravity on the Moon means that it can’t hold onto its atmosphere for longer than a few thousand years.

Once you got the process going, you’d need to be constantly replenishing our your orbital cottage with fresh atmosphere. Fortunately, we’ve got a whole Solar System’s worth of ice to exploit.

The benefits of a terraformed summer home on the Moon are numerous. For example, if the Moon had an atmosphere as thick as the Earth’s, you could strap on a pair of wings and fly around in the 1/6th gravity.

The enormous gravity of the Earth would pull the Moon’s oceans around the planet with 20 meter tides. You could surf the tide for kilometers as it washes across the surface in a miniature version of the shallow water scene in Interstellar.

This might be the greatest sponsorship opportunity for GoPro of all time. Look out Kiteboarding, you’re about to get more extreme.

Everyone always wants to talk about terraforming Venus or Mars. Let them be, that’s too much work. The next time someone brings it up at D&D night, you can blow their minds with your well crafted argument on why we want to start with the Moon.

I can remember David A. Hardy illustrating a few articles on future human habitats on the Moon, showing people enjoying themselves flying around and swimming at just such a lunar resort. One of these was for an article in the sadly short-lived space and astronomy magazine, New Voyager. The resort was in an enclosed dome, rather than on the terraformed surface. The Scots space scientist, Duncan Lunan, in his book, Man and the Planets, also suggested that to prevent the Moon’s atmosphere from being lost to space, the whole planet should be contained with a kind of giant inflatable bubble. This is waaaay beyond modern technological capability, but not, perhaps, that of the future. So perhaps at some point in the far future, the Moon may also join Earth as a living, habitable world.

David A. Hardy on Terraforming the Solar System

As well as colonising the other planets in the solar system with self-contained, sealed environments to protect their future human inhabitants, it may also one day be possible to terraform them. This means transforming them from their currently hostile conditions to an Earthlike environment. At the moment, the planet considered most suitable for terraforming is Mars, because of all the planets it seems to present the least obstacles to this form of planetary engineering. I can remember reading a piece in the Sunday Express way back in the 1980s, which discussed James Lovelock’s suggestions for creating an earthlike atmosphere on the Red Planet. Lovelock is the creator of the Gaia hypothesis, the theory that Earth’s biosphere acts like a gigantic, self-regulating organism. This became a favourite of several of the New Age neo-pagan religions in the 1990s, where it was incorporated into worship of the Earth Mother. Lovelock believed that while nuclear weapons were a serious danger to all life on Earth, they could be used creatively on Mars to produce an environment that would support life. Mars has large amounts of carbon dioxide locked up at its polar regions in the form of dry ice. he believed that this could be melted using nuclear missiles. Specially targeted nuclear explosions would cover the polar regions with an insulating layer of soil. This would keep the heat in, which is currently radiated back into space, reflected by the white ice. The rise in temperature would cause the dry ice to sublimate into carbon dioxide gas. This would then start a greenhouse effect, which would see more carbon dioxide and other gases released into the Martian atmosphere. This would eventually create an environment, where the atmosphere was thick enough for humans to be able to move around without space suits. They would, however, still need oxygen masks and tanks to be able to breathe. Lovelock was extremely optimistic about how many weapons would be needed. He believed that you’d only need four, if I remember correctly.

Lovelock’s ideas are wrong, but other scientists and Science Fiction writers have also suggested ways of transforming the Red Planet into a place where life can thrive. Back in the 1990s, Kim Stanley Robinson wrote a trilogy of books set on a Mars that was being colonised and terraformed by humanity, beginning with Red Mars. The veteran SF writer, Arthur C. Clarke, also produced a book in which he used to a computer programme to show what Mars may look like as it’s being terraformed. Over hundreds, perhaps even a thousand years, rivers, seas and oceans develop and green spreads over its land surface as vegetation begins growing on its previously barren surface.

David A. Hardy, the space artist, who has illustrated a number of books on space, including several with the late Patrick Moore, also described the various ways in which the Moon, as well as Mercury, Venus and Mars, could be terraformed in his 1981 book, Atlas of the Solar System (Kingswood, Surrey: World’s Work). He writes

Taking the concept of manned bases on other planets still further, there is the staggering possibility of ‘planetary engineering’ or terraforming – a term coined in 1942 by science fiction writer Jack Williamson. The idea is simply to make other worlds habitable by humans. An early suggestion, in 1961, by Carl Sagan was to ‘seed’ the atmosphere of Venus with blue-green algae, converting the carbon dioxide into oxygen and at the same time reducing the pressure and temperature (by eliminating the greenhouse effect). The upper clouds would condense and rain would fall, forming oceans.

A more recent alternative, now that we know how hostile Venus really is, is to ferry in ice asteroids 15 km or so in diameter, put them into orbit around Venus and aim them, using rocket jets, at a specific spot on the surface. Each crashes at nearly 100 km/s, at such an angle that Venus’ rotation is increased until a 24-hour day is approached, while at the same time water is provided as the ice melts. Then the atmosphere is seeded with blue-green algae.

The same could even be done with the Moon: once given a breathable atmosphere by baking oxygen out of the rocks with giant parabolic mirrors, it would remain for thousands of years, even if not replenished. The time factor for the operation is remarkably short. Mercury would need to be shielded from the Sun by a ‘parasol’ of rocky particles put up by mass-driver, or by a man-made ring. Mars would need to be warmed up, perhaps by reflecting sunlight on to the poles with huge, thin metal-foil mirrors, increasing the energy-flow at the poles by 20 per cent. or we could spread dark material from its carbonaceous moons on them with a mass-driver. Rich not only in carbon but in oxygen, nitrogen and hydrogen, this is excellent raw material for fertiliser. One the atmosphere was thickened, the greenhouse effect and carefully chosen plant life should do the rest. (pp. 86-7).

The process of transforming these planets into habitable worlds would take quite a long time – decades, if not centuries, and at present it is the stuff of science fiction. But I hope that there will be a time when we can move out from Earth to create new homes for life and civilisation on these worlds.