Re: Contaminating Mars

David Blenkinsop (
Sat, 11 Dec 1999 23:25:44 -0600

On Dec 9, 1999, wrote:

> In a message dated 12/8/99 17:01:14, wrote [DB: this was on "The Econ Ignorance of Space Fans" thread]:

> > If we land
> >actual humans on Mars at any point in the foreseeable future, don't we
> >automatically run the risk of *contaminating* the planet, in effect
> >seeding it with some of our own toughest microbes?
> This was already considered in designing spacecraft to go to Mars.
> The astronomers calculated rare asteriodal impacts on Earth had
> already resulted in several tons of viable material being dropped
> on Mars.
> So, not to worry. Mars is already contaminated. Europa too, I'll bet.
> Maybe Titan is relatively clean, but nothing closer.

Sounds kind of cool, to think that some living material has been going back and forth, on occasion, all along! Do you have any more detail on this, was the last possibly "viable" transfer apt to have been a million years ago, or ten million years ago, or something? If we get in a hurry to transfer some significant living material to Mars, *now*, doesn't that run the risk of confusing the whole issue, so that you'd wish you could've at least ruled out the chance that what's under your microscope was maybe brought along by astronauts, just lately?

The only reason that I can think of as to why this hasn't been talked about more is that people apparently can't avoid thinking about the future as a kind of repeat of certain kinds of frontiering that have happened in the past. In the past, it would have been impractical, to say the least, for explorers from Europe to avoid bringing their bacteria along to the New World! Now, though, if we have a relatively "sterile" option for exploring Mars via robot, at least until we've got a life assay of many surface sample locations, maybe that's the route we ought to follow? To risk sending humans very soon still sounds to me sort of like sending whole "boatloads" of potential bio-contaminants, possibly to the point of confusing some important life search results.

Mention of how people think of the future in terms of the past reminds me again of the seeming silliness of some of the scenarios in Kim Stanley Robinson's Mars books. I already mentioned the fact that Robinson's Mars settlers, some of them, anyway, were looking forward to exporting mass amounts of Mars metals to Earth -- IIRC, this was the main mention in the series of what one should be looking for in interplanetary commerce in the future. In this story line, corporate conglomerates were supposed to build a "Mars stalk" transport system primarily to enable this kind of material commerce. Surely though, the molecular construction needed for the "stalk" would also imply that the Earth people aren't that interested in mass metal shipping anymore! Fact is, transport of metals down railway lines was a big deal in our *past*, for developing commerce in the western parts of North America, for instance.

What I'm saying is, the future is apt to be *different* from the past in terms of how the economy is likely to develop, and also, perhaps, in terms of what's best for the integrity of key science findings, too.

David Blenkinsop <>