[Water on Mars!]

by Richard Cowen

NASA is turning up the publicity to keep our dollars flowing into space research. As a card-carrying scientist, I think it's a good idea. Both the science and the adventure are exciting. I just wish that NASA wouldn't distort reality as if it were writing ads for TV.

For example, NASA sent a spacecraft to map the planet Venus. But when the images came back, it cheated. The "problem" was that Venus has low wimpy volcanoes. So NASA distorted the computer images to make the volcanoes of Venus look like Earth's tall majestic ones. And it tinted them red to make the rocks look hot (that was fake, as well).

Then there were "bacteria from Mars". These were microscopic blobs discovered in meteorites from Mars, collected from the ice of Antarctica. NASA called a press conference and showed an expert the pictures, live on TV. "Sure look like bacteria to me", he said. Soon they became bacteria, in press releases, on TV, and in magazines at the checkout stand.

The trouble was, the expert was set up. NASA didn't tell him how small the blobs were: 1000 times smaller than any living cell on Earth. You don't need many working parts to run a bacterium, but you do need some. Those blobs could not contain enough biological bits to run a bacterium. They never could have been bacteria, from Mars or anywhere else.

Here we go again. Water on Mars! Newsweek, Time, TV, they all say so. And there probably is. But does it make any difference to the human race? You judge.

Little planets don't have much gravity. On Mars or Moon, if you pour water on to the surface, it will first freeze and then evaporate. And because gravity is weak, the evaporated water will drift off into space, never to return as rain as it does on Earth. That's why Mars and Moon are deserts and Earth is not. Water on the surface of Mars is on a one-way trip into space.

Yet there are scars on the surface of Mars that were clearly left by water. They are evidence of giant floods in the past on Mars, bigger than the biggest ones we have ever had on Earth. Isn't this impossible?

No, because ultimately water comes from volcanoes, which erupt lots of steam along with lava and volcanic ash. On Earth, that steam condenses into rain, and continually tops up the oceans that have existed on Earth for billions of years.

Mars has volcanoes, giant ones, but they have been dead for a long time. Long ago, they supplied water to the surface of Mars, probably as occasional large floods. But most of the water evaporated to space. Only a little that seeped into the Martian sands was preserved underground, as ice.

Now we have new pictures of gullies on Mars, each one leading to a small patch of floodplain. And the gullies look fresh! "Water on Mars!!" scream the headlines, and folks who should know better pontificate about human settlement of the Red Planet.

Rubbish! The images show utterly convincing evidence of water erosion. But we are not talking about rivers. We are talking about small flash floods. Not flash floods two or three times a year, like those of Death Valley. These are one-time flash floods. They tap the underground ice of Mars, and that ice can only be melted once. Once it pours out on to the surface, it evaporates to space and is gone. For ever.

So where are humans going to live on Mars? The ice has already gone from the warmer areas, and from places with fresh evidence of floods. We'd hope to find some places that still have ice.

How much water could we find? The gullies allow us to estimate how much water was used to mold them. The answer is in little tiny print in the report. A 4-acre parcel holds something over half a million gallons of water. Sounds a lot, until you work it out. That's the equivalent of about 6 inches of rain. And that's all the water you are ever going to get for your 4-acre parcel, for all your personal and domestic needs, to grow food with, and to wash the spacecraft on weekends.

You've seen those sand-blasted, bullet-scarred old real estate signs in the desert: for sale by owner, prime location, 4 acres, along the dirt road that leads to a dying cottonwood with an old trailer and three dead cars under it. Even if you were remotely tempted, wouldn't you ask about water? And the reply comes, 20 gallons a minute for a couple of weeks, and then she's dry. For ever. Less than 3 acre-feet. And you drive away.

Nowhere on Earth has less water than the wettest place on Mars. (And you can't breathe the air on Mars.) Before you would live on Mars, you would live in the middle of the Sahara Desert.

There are novels that describe the Terraforming of Mars. Do not be fooled: that is science fiction, not science. The human race had better get to grips with the fact that we live on the only habitable planet in the solar system. And we had better take care of it, simply because it's the only one we've got. If NASA can spare us some money, let's spend it on ways to keep Earth healthy for us: it's simply good science and good sense.

Set aside the hype. The new images from Mars allow us to see how lucky we are to have Earth. We have never detected life anywhere else in the Universe. In fact, we may be it. In the end, thanks to NASA for the insight. Aren't we special? Isn't science wonderful?

Richard Cowen

Published in the Davis Enterprise, July 2000.