There are lots of things you shouldn't put in a microwave. Like grapes, which morph into glowing balls of plasma. Or ivory soap, which curdles into an abominable snowman-like blob nearly three times its original size. If you nuke a CD with the lights out, you're in for a light show, and if you nuke a wet poodle, well, let's just say it's not a pretty sight.
But it wasn't until Dr. Lawrence A. Taylor came along that anyone thought to microwave lunar soil.
Recalling his now-famous microwave experiment, Taylor, a University of Tennessee distinguished professor and director of the school's Planetary Geosciences Institute, reaches across his cluttered desk into the side pocket of an oversized black bag. After a few seconds of digging, he pulls out a small vial half-filled with fine, pewter-gray powder. "This is Apollo 11 soil," he says, holding it up and peering into the thick glass. "This was collected by Neil Armstrong, from Apollo 11."
Rare as lunar soil samples are on Earth (most scientists perform their experiments using a simulated substitute) Taylor has thousands of them, harvested from various regions of the moon during various missions. He suspects that having access to the real deal is one reason why he's made so many discoveries about lunar soil's properties. "There's nothing that accurately simulates lunar soil because it's so unique," he says. "Working with the real thing gives you a big advantage."
But that's hardly the only reason why Taylor is widely considered one of the top scientists in his field. For starters, he's been in the business of lunar research for 35 years, a boast only three or four people in the world can lay claim to, though he still compares himself to "a little kid in a candy store" when he's working. He was there, for instance, during man's last moon mission, Apollo 17 on Dec. 14, 1972, advising astronauts in space from the ground. Since then, with a little help from NASA, he's continued pushing his research into uncharted waters, his interest in lunar rock and soils expanding into a curiosity about meteorites, terrestrial mantle samples and diamonds.
And then there's his inquisitive streak, manifest in an interminable stream of questions that begin with, "What if...?" For example, "What if you put lunar soil in a microwave?" But when Taylor zapped a pinch of extraterrestrial dust in an old kitchen microwave one day, there's no way he could have known the doors of possibility he was opening. "Weird people putting weird things in the microwave," the professor says, grinning. "It was serendipity."
The short answer to what happened that day is, the lunar soil melted and cooled into a glassy solid. Rapidly. Faster even than a microwave can bring tea water to a boil. "That means it couples more favorably with microwave energy in a normal kitchen microwave oven than does your water. And the oven was made for the water, obviously," he explains. (Microwave ovens work by passing electromagnetic radiation through the substance being heated, which excites its water molecules. When water molecules become excited, they heat up, in effect heating up the rest of the substance.)
Taylor's next question, he says, was directed toward practical application: "What does this mean? What can we do with this?"
Taylor picks up the vial of lunar soil and shakes it a little, observing the tiny particles. The moon, he explains, is constantly being bombarded by tiny micrometeorites, smaller than the eye can see. They rain down at great speed, and when they hit the moon's surface, they break its soil into smaller and smaller grains. "It's kind of like taking a rock and smashing it into little pieces," Taylor explains.
In the process, because the micrometeorites have so much energy, portions of the soil are melted into glass, within which billions upon billions of little pieces of iron are suspended, and gases contained within the soil vaporize. Under a high-powered microscope, gaping holes from where gases have escaped give the soil particles the appearance of Swiss cheese.
"It has some very strange characteristics," Taylor notes, pulling a magnet out of his desk to illustrate yet another of them. As he passes the magnet over the vial, the lunar soil particles leap up to greet it though the glass. "You'll notice a particular property that we really didn't appreciate until just a few years ago. That's when I discovered the soil is almost entirely magnetic."
Taylor recalls explaining his discovery to Harrison "Jack" Schmitt, an Apollo 17 astronaut and the last man to step foot on the moon, in this very office. "Jack was sitting over in the chair there and I was telling him about this magnetic property and he says, 'Remember all the problems we had on the moon with dust?'"
During the Apollo 17 mission, moon dust--being extremely dry, fine-grained and electrostatically charged--was everywhere . And with each step the astronaut took, it got worse. It got in the improperly sealed rock boxes that were made at Oak Ridge for a million dollars, obscured the lens of Schmitt's camera, settled into his helmet and turned his white space suit black. Considering the intense heat (there's minimal atmosphere on the moon to diffuse the sun's rays), the latter could easily have turned into a dangerous situation.
"Black absorbs sunlight," Taylor explains. "The temperature inside his suit became warmer and warmer, and his life-support system on his back, this 120 pounds on his back, had difficulty handling it."
It was a problem they hadn't anticipated, but it could have been lessened, as Schmitt later pointed out, by having a magnetic brush on hand. Or eliminated, if there was some way to eradicate the dust altogether.
Enter Taylor's moon-dust-in-the-microwave experiment, and a little imagination.
His idea? A kind of microwave on wheels, a lunar Zamboni designed to pave roads by melting surface moon dust into thick, solid sheets of glass. "You could suture the soil down to a foot," Taylor says. "You could make it sort of like a brick down to a foot... You could make glass roads."
You could even pave a landing pad, he says, greatly reducing the scale of the dustbowls that erupt upon landing. "When we land, we blow dust three ways to hell and back," he says. "Dust goes every which way."
For instance, when Apollo 12 landed on the moon somewhat near a surveyor module that had been placed there some years before, the astronauts were surprised to find that parts of the module had been literally sandblasted by dust raised up from the landing--even though it was hundreds of meters away. But since the moon has only one-sixth the gravity of Earth and very little atmosphere, there was nothing to slow the dust down or lessen the impact.
A landing pad would keep the astronomers happy as well. Astronomers like to set up shop on the backside of the moon, the one place in the solar system that never faces earth. Since there's no interference from radio waves or static from Earth, it's the ideal locale for radio telescopes looking and listening out into space. "But the astronomers keep saying that when you raise up all this dust, not all of it settles. Some of it becomes electrostatically levitated and becomes like a fine layer of material that our telescopes have to see through," Taylor says.
The long-term goal of this problem-solving, of course, is to create an environment that will someday be conducive to human life. Finding ways to keep the dust down, whether it's via road-building or magnetic air filters, is a major part of it, although there are other challenges as well. "The major concept that people have to accept is one that our forefathers took for granted: You have to learn to live off the land," Taylor says.
That's because it's fantastically expensive to take anything to the moon, costing between $10,000 and $20,000 to transport a single pound. So mankind will have to learn to literally make its own water, its own air, even the materials it uses to build a home--all of which are actually more feasible than they might sound.
If you have oxygen and hydrogen, for instance, you have all you need to make H20. And both elements are available on the moon; neutron spectrometers have detected the presence of hydrogen at the poles, although further tests are needed to determine whether it's in the form of water ice or solar wind (manifest in the soil, i.e. if you heat up lunar soil, hydrogen is released). And Taylor says there are some 20 different processes by which oxygen can be produced on the moon as well.
Then there's the question of what regions of the moon are inhabitable. Around the equator, where communication with Earth is best and lunar soil is the richest, temperatures range from 125 degrees Celsius (257 degrees Fahrenheit) during the day to -150 degrees Celsius (-238 degrees Fahrenheit) at night--"a killer," Taylor says. At the poles, the temperature swings are milder and, because the sun is always visible, solar panels could be used for energy, but other resources like minerals are limited. "I go to the pole, I have one big thing. I go to the equator, I have another," Taylor says. "It's a tradeoff."
When President Bush announced in 2004 that man was going back to the moon, these were among the questions that rose to the forefront of many NASA scientists' minds. There are still a lot of blanks that need to be filled in, but explorations are already being planned that should provide some critical answers. "By the end of next year, 2008, we should have a lot more data as to where exactly to go," Taylor says. "It's sort of like making a flow-sheet: If you do this and get to this point, it's either yes or no. If it's yes, it goes down to this. If it's no, it goes down to something else."
Variables aside, Taylor predicts that man will return to the moon in six, eight, maybe 10 years. It will mark the first human footstep on lunar soil since 1972. "I lived through Apollo, and that was supposed to be the beginning of mankind's venture into space and it got shut down," he says. "And because of that, there's been two generations go by where there hasn't been a pass-[of-]the-baton."
Taylor says that although he doesn't expect to ever make it to the moon himself, he has no intentions of ceasing his own lunar explorations from afar. "I'll never retire," he says, "not as long as I'm having fun."
Speculating about what life will be like on the moon, Taylor's voice grows animated, excitable, childlike. "Just think, when you're lying in your bed and you have a lumpy mattress, if you have 1/6 gravity, you wouldn't feel the lumps. When you went outside to hit your golf ball, you'd hit it and you'd drive it for a mile. You'd have the Olympic games and they'd be jumping not seven feet, but maybe 40 feet--ridiculous things...."