Water is scarce on the Moon. It may not be present naturally in sufficient quantities to support a significant population. The story assumes this is the case – and makes provision for getting it there.
How? By harvesting the solar wind.
Now hang on a minute! The solar wind is incredibly tenous: around three or four protons per cubic centimetre of space in the neighbourhood of Earth.
But these protons are moving fast – and in one second a 400-800 km column of them flies through that paltry cubic centimetre.
Water (H₂O) is a compound of hydrogen and oxygen. Oxygen is as abundant in Moon rock as it is in the earth’s crust, i.e. very. So all that’s needed is energy, lots of it, to break down “sial” and “sima”, the oxides of silicon, aluminium and magnesium which make up moon rock. Plus hydrogen.
Now what does (ionised) hydrogen consist of? Protons.
And the solar wind, if harvested over a wide enough area, gives us protons: very, very energetic protons.
- An Adin Beam is a beam of protons focussed from the solar wind by means of a Fresnel lens of concentric superconducting rings placed at the L4 and L5 libration points of the Earth-Moon system. These focus the beam onto a series of orbiting collimators as they come past. The collimator, or Adin satellite, directs it to a precise surface target.
- Adin’s Process is the chemical process of making water on the Moon (plus some useful by-products like magnesium and aluminium) by directing an Adin Beam onto the surface to react with moon rock.
Here is a description of Adin’s process from The Titan Kiss:
Kitty shielded her eyes. The Sun was low in the sky, hovering over the crater rim. Another hour and it would be sunset—the start of the Fort Night. It would get seriously cold.
But it wasn’t just the Sun that was shining straight ahead of them. There in the middle of the crater was a vast hemispherical cloud, lit-up from below by a blood-orange glare. Vapour billowed up, glowing white in the sunlight.
“That’s an Adin beam.”
“Adin beam. It’s the main source of water on the Moon. You’re looking at a waterworks.”
“Geddaway!” Jack turned to face her. “Where’s the reservoir—the filter-tanks?”
“There aren’t any. That’s a pure beam of protons coming down there. When they hit the bottom of the Adin crucible they turn into hydrogen to make water.”
“So where are the protons coming from?” Jack gazed searchingly into the sky. “I can’t see a great big flashlight up there beaming down.”
“Oh you can see the Adin satellites with the naked eye, if you know what you’re looking for,” said Kitty. “Way out there at the L4/L5 Lagrange points there are huge Fresnel lenses hundreds of miles across which focus the solar wind.”
“What do you mean, ‘focus the solar wind’? It’s incredibly tenuous. We’re talking about three or four protons per cubic centimetre of space. I remember that from my schooldays.”
“Yeah, but they zip along. So in one second a lot fly past.”
“The lenses are not made of glass, surely?”
“No. Very thin superconducting wire in a double spiral. It sets up a magnetic field that focuses the protons inwards and deflects the electrons the other way.”
“So there’s these great big cobweb things up there, focusing hot-spots on the surface?”
“Not quite. The focus of the Fresnel lens is moved by varying the currents in the wires, but it’s not precise enough for the surface. Besides, the geometry’s all wrong. Instead there’s a number of so-called Adin satellites in orbit. As each comes past it grabs a primary beam, collimates it and focusses it down here. Don’t worry, it’s fail-safe. If the primary beam misses the collimator it defocuses again before it reaches the surface so it can’t do any damage.”
“That’s still a pretty energetic beam over there, flower.”
“Sure. Enough energy to melt moon rock and release oxygen from the silicates. By-products: magnesium, silicon and aluminum in the metallic state. When the protons have given up their energy and come to rest they marry the local electrons to make hydrogen—which combines with the oxygen they’ve just released to give us H2O. Water. That’s Adin’s Process.”
Jack was impressed—and not a little humbled. “You went to a better school than I did,” he muttered. “Tell me, hinny—that beam isn’t likely to drift off-target and toast us, is it? Or do you reckon it would steam us?”
“It would blast us to atoms,” replied Kitty. Seeing the expression on his face, she nudged his ribs. “Don’t get scared now. Each collimator has the crucible co-ordinates firmly lodged in its memory. They sure take care nothing goes wrong. Why—a beam that powerful could burn the heart out of Jordvik.”
But it did go wrong… and the result was the Gaiascope Atrocity, for which Peter Zwillinge is generally blamed in Anitra’s Petition – and for which Moonforce Commissioner Jutta Nilsson is hunting him down across the Four Worlds.