Gregory Benford's Guide to Terraforming the Moon

When it comes to remaking a celestial body in Earth’s image—“terraforming” it—the moon has clear advantages: It gets twice the sunlight of Mars. It’s a three-day trip with current technology, while getting people to Mars would take six months. Furthermore, the moon is dead and it’s small, so it needs less work and investment to build an atmosphere. Mars has slightly less than the total area of Earth’s dry land; the moon has a quarter of it—a bit smaller than all Asia.

Still, engineering any planet or satellite, including Earth, is a huge job. We will probably encounter the true scale of it in this century, as we build defenses against climate change. Thinking through how we might thrive on other worlds, even in the far future, can make us reflect on how terraforming Earth or other worlds will alter the human perspectives.

Terraforming our moon will take many decades and vast abilities. Before we can begin, we’ll have to master the resources of our solar system—especially transporting raw masses over interplanetary distances. That means nuclear thermal rockets (which we already developed by the 1970s), advanced robotics and communications, biotech, and sustainable closed environments. Once those come, we can reach higher. Here’s how the terraforming process might work.

Our moon was born too small to harbor life. It came from the collision of a Mars-sized world into the primordial Earth. From that colossal crunch spun a disk of rocks that condensed into a satellite. The sun robbed its gases, and that bully Earth slowly stole the moon’s spin, locking it so that one face always smiles at us.

The moon’s closeness is a huge advantage: To make it habitable, we would first have to bombard it with water-ice comets, a tricky endeavor best attempted with the many resources waiting on and near Earth. Using incoming comets will be worth the challenges, because they can deliver both an atmosphere and momentum.

The process begins by steering a comet nucleus, which some call an iceteroid, from the chilly freezer beyond Pluto. Nudge it from its slow orbit with a mile-per-second velocity change and swing it near any gas giant planet for a momentum swerve. By hooking the comet adroitly in a reverse swing-by around, say, Jupiter, we can loop it into an orbit opposite to the way that worlds orbit the sun. The grimy, mountain-size iceteroid soon will loom in the moon’s night sky.

Mere days before it strikes, scientists will have to blow it apart—brutally and carefully. Ice shards come gliding in all around the moon’s equator, small enough that they cannot free themselves from gravity’s grip. (We can’t let big chunks of comet scatter off the moon to rain down as celestial buckshot on Earth.) Within hours of the first incoming comet, the moon will have a crude atmosphere. With one-sixth of Earth’s gravity, it can hold gases for tens of thousands of years.

As more comets arrive and pellets pelt down, the moon spins faster. From its lazy “day” cycle of 28 days, it speeds up to a 60 hours—close enough to Earthlike, as they say, for government work.

For most of its life, the moon’s axial tilt has been a dull zero, robbing it of summers and winters. But if they are angled just so, the incoming ice nuggets can tilt the poles while shortening the days. From such simple mechanics we conjure seasons.

All told, we’ll need about 100 comets the size of Halley’s, which will bring water and carbon dioxide, with smidgens of methane and ammonia. We’ll need nitrogen, too, and some magic from the biochemists, who will pepper the moon’s old, gray rocks with blue-green algae that can exhale oxygen.

For centuries the moon’s dark plains had carried humanity’s imposed, watery names: Tranquility, Serenity, Crises, Clouds, Storms. Now, thanks to the “rain” of iceteroids, these lowlands of aged lava catch the rains and fatten muds into ponds, lakes, true seas. After billions of years, the ancient names come true.

Genetically engineered plants will create the first greenery. Like Earth’s tropics now, at the moon’s equator heat drives moist gases aloft. Cooler gas flow from the poles to fill in. The high wet clouds skate poleward, cool, and rain down.

On Earth, such currents are robbed of their water about one-third of the way to the poles, creating the worldwide belt of deserts. Not so on the moon. The new world has no chains of deserts, just one simple circulating air cell grinding away in each hemisphere. Moisture forges climate. Northerly winds sweep poleward, swerving toward the west to make the occasional mild tornado.

The moon, once “the lesser light that rules the night,” now shines five times brighter, casting sharp shadows on Earth. Because of the reflection of the seas, when the alignment is right, people on Earth’s night side gaze up at Earth’s image.

The moon has no soil, only the damaged dust left from 4 billion years beneath the solar wind’s anvil. Making soil from gritty grime is work best left to the biologists. Our moon can brew its own, in fast-forward. Bioengineered minions can till the dirt, massage the gases, build an ecology.

In the one-sixth gravity, humans can fly, with flaps on arms and feet. At last we will be at one with the birds—big rude beasts who will challenge us among the thick decks of pewter cloud.

This exotic Floridalike globe with the land mass of Asia will have mostly cloudy days. It’ll be warmer, too, from greenhouse effects. Earth will still hold sway over a moon revolving much faster, making its presence felt even if you can’t see it most of the time. The tides will be 20 yards high—and so can be surfed. With lesser gravity, a boarder can skate over hundreds of miles, a daylong ride. Of course, when that tide slides up the shore of a lunar lake, there’ll be plenty of tourists scampering away from it.

This sobering step to a higher level could mark a defining role for an emergent humanity, securing its future with a new, distant habitat. We may finally become, millennia after the Old Testament commanded, true stewards of the Earth—and no doubt, more.

We cannot have a future that we do not first imagine. Historians often convey the impression that the past, since it is now fixed, was a neat, cut-and-dry time. This mistake makes the present seem messy. The past is a far country, but the distance should not confuse us about its turbulent nature. […] We shape our future with incomplete information, then must live with what results.

Gregory Benford,

The Wonderful Future That Never Was

There was a blithe certainty that came from first comprehending the full Einstein field equations, arabesques of Greek letters clinging tenuously to the page, a gossamer web. They seemed insubstantial when you first saw them, a string of squiggles. Yet to follow the delicate tensors as they contracted, as the superscripts paired with subscripts, collapsing mathematically into concrete classical entities– potential; mass; forces vectoring in a curved geometry– that was a sublime experience. The iron fist of the real, inside the velvet glove of airy mathematics.
—  Gregory Benford

I decided to take a trip both back in time and into the future and read Gregory Benford’s Galactic Centre series of books. They are considered Science Fiction classics but for some reason I have never read them. This was the time to make up for that shortfall my book pile dwindling for the first time in many years due to illness. I read his Novel “Foundations Fear” (part of the Bear, Benford, Brin, Isaac Asimov legacy) many years ago and thought it truly magnificent but somehow I had never read what is considered his masterwork.

This is the first novel in a series of eight and so expect more reviews on them salted through others.  I have to be honest and say that this novel was a terrible disappointment though it is not bad. I suspect that it had its time in the early seventies and has faded as other more impressive Sci-fi writers have come along doing the same things but having learned from the likes of this man know how to do it better. I do not mean to fault it, as it is a well put together tale. For the time this was written I suspect it was faultless but the likes of Iain M Banks and Dan Simmons make the originality look woefully old and creaky though i suspect it was groundbreaking at the time.

Like many of these Hard Science fiction books I suspect that if i had read this in the seventies I would have said; wow. It is dated and was clearly of its time even if visionary. I must say that I feel rather rotten but two stars out of five. I apologise to Mr Benford. I suspect it is the period when it was written rather than the novel itself.

How Asteroid Mining Could Open Up the Solar System (Podcast Transcript)

Asteroid mining is considered by many to be a key to the colonization of outer space, the space equivalent of California’s Gold Rush. NASA is planning missions to advance asteroid mining — OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security and Regolith Explorer) — in partnership with two leading private industries: Planetary Resources, Inc. and Deep Space Industries. Gregory Benford is a professor of physics at the University of California, Irvine, and conducts research in plasma turbulence and astrophysics.

Notable: 100 Year Starship Symposium

For example, Jim and I think the most likely first unmanned “ship” will be a beam driven sail that makes a sundiver fall to get a boost from maybe 1/100th of our orbital radius, then gets pushed by beamed laser or microwave beams to very high speeds. The physics of that we now understand; Jim and I worked on the basics in the early 2000s—stability, steering, high acceleration. We even lifted a carbon fiber sail against gravity at JPL. With the basic physics done, it’s merely engineering… but what fascinating prospects! The sail papers were all promising.

What about larger payloads? We’ve hit the engineering wall, going as far as we can with chemical propulsion systems. If we’re going to make it to Mars in any sort of reasonable timeframe or with healthy transit durations, nuclear is the obvious next step.

Indeed, if NASA doesn’t show the world it has a goal—which should be Mars, certainly–and will develop the means to go there, it will be deeply cut in the budget battles soon to come. The Webb space telescope, now projected to cost $9 billion (ten times the initial supposed cost), is the only good project they have on hand. If we put it into the L2 point at Earth’s shadow as planned, we’d better be able to service it, to get long term performance from such a huge expense. That’s hard and expensive to do with chemical rockets.

Nuclear thermal rockets are the sole economical way we have to reach such places, four times further away than the moon.


I was just thinking how perfectly Gregory Benford’s Mantis bots from “Great Sky River” would fit into the SCP universe.

For those of you who don’t know, the Mantis is the unrelenting pursuer of humans and designated antagonist that is about 30 ft tall, gangly as heck, and has wires hanging off its limbs. It hides from people by projecting images of the background around itself.

When it encounters a person, it will shoot a hot beam through their eyes that will travel down to the rest of your body. Memories flash across their vision as they are forgotten and said person is left as a bloated carcass appearing to have pinprick perforations all over the body, pus leaking from the eyes.

What actually happens is the Mantis is stealing memories and wiping their brain entirely clean.

Spoilers below the cut.

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