The moon: What's science got to do with it?

For many, the moon has lost its allure as an object of mystery and conquest, supplanted by a larger and more distant orb, Mars (below)

ALSO Apollo product spinoffs advanced terrestrial life

INTERACTIVE Defining Images

July 13, 1999
Web posted at: 6:30 p.m. EDT (2230 GMT)

By Robin Lloyd
CNN Interactive Senior Writer

(CNN) -- Thirty years ago NASA scored a technological and political triumph when astronaut Neil Armstrong set foot on the moon.

In the next three years, astronauts with the U.S. space agency returned to our lonely, gray neighbor five times before the Apollo program ended, bringing back enough lunar rocks and dirt to keep dozens of scientists busy for a lifetime.

But something got a bit lost in history after the ticker tape parades and Soviet Union butt-kicking.

The moon.

How about moon colonies? Moon science? Even lunar commerce?

Jeffrey G. Taylor, a University of Hawaii geophysicist, started working on Apollo rocks in 1970 as some of the hottest Apollo data came in. He continues to work with them today.

"The Apollo program was no scientific expedition," he says. "It was a big political event."

Yet, a tremendous side-benefit was a truckload of scientific data, he says.

"In those six landing sites, they brought back a lot of rock and dirt that has kept some of us occupied 'til now," Taylor says. "We are still digging into these samples partly because they are complicated and partly because we have new ways to analyze them."

After Apollo, scientists reported stunning details about the moon. It is 4.5 billion years old - about the same age as Earth. It is made of ancient rocky stuff that has been melted, erupted and crushed by meteorites.

And that well-preserved rocky stuff, at least that returned by Apollo missions, contains not a shred of life. But it does contain a lot of clues about the age of our planet and its neighbors and how they all evolved.

Apollo's scientific mother-lode

Scientists who work with Apollo data now say that the moon's rocky matter sits atop a thick crust (60 km). Below that lie a fairly uniform lithosphere (940 km), a small liquid athenosphere (740 km) and a small core.

The youngest moon rocks are nearly as old as the oldest Earth rocks. The earliest processes and events that probably affected both planetary bodies can now only be found on the moon.

Scientists learned that the moon and Earth are different mixes of the same reservoir of materials.

In the final years of Apollo, there was talk of lunar colonies and exploiting the moon for commercial purposes.

Then a mountain of social upheaval in the United States and elsewhere buried all talk of future lunar exploration or exploitation.

Lunar lapse

What followed Apollo 17 was a 22-year break in American missions to the moon. During those years, university scientists picked away with little fanfare at their Apollo data. Six more USSR probes landed on the moon after Apollo 11, but even that effort wound down in August 1976 with a sample return mission.

Astronaut Harrison Schmitt in Lunar Roving Vehicle during Apollo 17 mission to the moon December, 1972

Finally, in 1994, the U.S. Department of Defense's Clementine probe circled the moon and gave the first indications of water there. The Lunar Prospector spacecraft followed in January 1998, performing a mapping mission on a paltry $63 million budget. The project was headed up by Alan Binder of the Lunar Research Institute.

Taylor said NASA rationalized its long lunar exploration break by saying there already was a mountain of data on the moon and nothing on the planets -- which was true in some ways.

Clementine arose, he said, due to some "space cadets" in the military. "That was lucky. Then I think we got Lunar Prospector because Alan came in with it so cheap," Taylor said.

"He worked on it for a long time. He was just tenacious. When the time was right, he got it. It was cheaper than Clementine and NASA was a little stung by the idea that military did a $75 million mission."

Prospector jump-starts moon science

The launch of Lunar Prospector marked the start of a new chapter in American lunar exploration. The goal: to do what previous missions left undone by mapping of the entire lunar surface and closely analyzing the moon's composition.

At the end of the Apollo missions, 75 percent of the moon's surface remained unmapped. The Apollo spacecraft had stayed close to the lunar equator, landing near dusty seas where exposure to the sun had evaporated any traces of water years ago.

Apollo just skimmed the scientific surface of the moon, Binder says. The moon has a surface area equal to North and South America combined, but U.S. astronauts with Apollo spent only a total of three working days there. For Binder, that is hardly enough.

"We're talking about a whole world to explore," he says.

The Lunar Prospector's 18-month mapping mission is set for a grand finale on July 31 with a crash that has a slim possibility of yielding some information about the moon's most precious and recently discovered resource -- water.

One important question sprang to light in 1994, when the Clementine probe found signs of water far below the lunar surface. While the moon has no indigenous water, the impact of long-ago comets -- which are rocky balls of ice -- may have left ice crystals below.

Why does water matter?

Simply put, it's the single most essential substance for humans and their machines.

"Water is probably one of the most valuable strategic materials we can find in the solar system," said Dr. Paul Spudis of the Lunar and Planetary Institute.

Water, of course, is a necessity for human life. But it can also be split into hydrogen and oxygen -- the two components of rocket fuel.

All of which is fine, of course. But why on Earth would anyone want to build a rocket on the moon? It's a weighty question that demands a lightweight answer.

The moon's gravity is a fraction of Earth's, and the escape velocity -- the speed that a spaceship has to reach to escape its gravitational pull -- is a mere 2.38 kilometers (1.4 miles) per second, compared to Earth's 11.2 km/second (about 7 miles/second).

That's why some experts treat a base on the moon as essential to manned missions to the planets. Launching from the moon leaves more fuel for the rest of the trip and extends the range of the mission.

At the shady poles, where Prospector focused its search, scientists found evidence that ice crystals lurk in countless dots sprinkled throughout the lunar surface. All those dots are estimated to add up to enough water to fill a lake 4 square miles in area and 35 feet deep.

The mission didn't show direct evidence of water, just an electromagnetic signature for hydrogen -- a likely sign of water. So far.

Hopes for a Prospector splashdown

Binder hopes to get his first direct evidence when the 158-kilogram (327-pound) spacecraft is intentionally smashed at 1.7 kilometers (1 mile) an hour into the moon's surface. The goal is to crash into a crater the size of a small city that Binder believes is filled with water ice.

"The trick is that we want to find out if it's really water that we're mapping," Binder says.

If Binder is right, the spacecraft's impact will throw up a huge plume of water vapor that can be seen by spectroscopes at the Keck Observatory on Mauna Kea, Hawaii, and other telescopes like the orbiting Hubble Space Telescope.

"Then we don't have to say that we infer water," Binder says. "We will know that it's water that we found."

The hitch is that the idea has an admittedly low probability of success -- about 10 percent, Binder says.

Regardless of the crash results, Prospector has been a phenomenal success for its price tag.

It has yielded five global maps:

• A gravity map, which tells the structure of the moon's surface crystals.

• A magnetic map that will yield a better estimate of the moon's core -- which now appears to be tiny, less than 1 percent of the moon's mass.

• A water, or at least, hydrogen map.

Prospector also has mapped the location of 12 elements spread across the moon's surface.

"We had a tantalizing indication (after Apollo) of what the global structure of the moon was but when you've only seen 20 percent maximum of the surface, you don't know what you've got," Binder says. "Now we know exactly what's going on. This is a big jump forward."

The future of the moon

Oddly, Binder's motivation for the Prospector mission, which he pitched at NASA for years before they bit, was not so much scientific as it was to show that you could do lunar exploration inexpensively with off-the-shelf hardware.

His Lunar Research Institute is designed to pave the way for NASA's future, getting outside funding for its future missions to later sell the data to NASA.

Binder, a frustrated astronaut, said NASA "threw away" the capacity to fully explore and exploit the moon 25 years ago.

"Prospector is starting that process again and doing it commercially," he says.

He paints a picture where humanity colonizes space, including the moon and Mars. Moon miners will gather helium isotopes plentiful on the moon and figure out how to use them to create nuclear fusion energy. Mars-bound spacecraft could use the moon as a fueling station, cutting costs enormously.

Taylor has similar visions, a bit more science-focused, that start with robotic exploration of the South Pole where there could be chunks of the lunar mantle laying around, as well as water ice.

The moon also is good place to do space-based astronomy, he says, but we would need humans there to fix the instruments. The moon could be an excellent observatory, he said, moving slowly rather than whipping around like current space telescopes.

The moon also has a more stable surface than the Earth and no atmospheric interference.

"That means you can spread out a baseline of optical telescopes for interferometry," Taylor says. "It would be really big. At Mauna Kea (Hawaii) they are hooking up the two Keck telescopes with a 100-meter baseline. On the moon, they could have a 10 kilometer (6 mile) baseline."

The moon also is big enough for huge steerable radio telescopes, bigger than the steerable dishes at the Very Large Array in New Mexico, Taylor says, hardly able to contain his excitement.

Binder talks broadly of installing huge solar panels on the moon to collect energy and ship it back to Earth -- especially to Third World countries starved for power.

These are hardly new ideas. In fact, they are about 25 years old, about the age of the Apollo program. Binder is just one of the few speaking frequently about it again -- partly because his plan is independent of government funding.

"The moon will become the New York City of the Earth complex in the future," Binder says.

CNN Interactive Associate Editor Andy Walton contributed to this report.