91av

Realise human potential vs Minimise suffering of other life forms

Next stop, Mars. Space agencies and private companies alike plan to send humans to the Red Planet in the next decade, with the idea of permanent settlements twinkling in the future. As the technical challenges of such missions are conquered one by one, it’s past time to ask: is taking over another world the right thing to do?

This question, like so many ethical quandaries, comes down to rights: does life on other worlds have the same rights as Earth life? What if it’s just microbes? And what if there is no life at all? Do humans have the right to leave muddy bootprints on pristine planets, potentially stamping out future civilisations before they arise?

“There’s this idea lurking behind all of this that the universe has a natural way of doing things and that humans come in and mess it up,” says Kelly Smith, a philosopher at Clemson University in South Carolina. But, Smith says, humans are also part of the natural world, and not everything we do is bad, so a human settlement might enhance nature’s pristine splendour rather than ruin it.

That’s not to say we shouldn’t tread carefully. Even now, when we send spacecraft to hover near other worlds, we take great pains to ensure they are as clean as possible to avoid contaminating the planet or moon with Earth life. Of course, this consideration doesn’t arise out of respect for other worlds so much as the fear that it could render them useless for scientific study.

But settling humans on another planet would be a big step – make that a giant leap. Rather than mere contamination, it would probably mean overrunning or exterminating any native organisms outright.

Would that give us pause? On Mars, say, the most probable life forms are microbes. And when it comes to microbes on Earth, says Margaret Race, a biologist with the SETI institute in California, “we are killers, and deliberately so”, murdering them with pesticides, antibiotics and soap every day.

Once the excitement surrounding any discovery of extraterrestrial microbes had faded, their eradication would seem a small price to pay for an expansion of human civilisation. “If we did destroy Martian microbes to create a new human society on Mars, I would argue that what we created is a whole lot more valuable than what we lost,” says Smith.

That means we would have a responsibility to create a successful society, forcing us to take a hard look at the way we have changed and maintained our own world. “The idea that we could just take a whole planet and massively transform it to make it habitable for ourselves – gosh, we just did that and it’s not going so well,” says Maria Lane at the University of New Mexico.

If Earth becomes so uninhabitable that we need another planet as a lifeboat, what’s to say we won’t do the same again? Colonising the universe is all well and good, but not if we leave a trail of pillaged worlds in our wake.

This article appeared in print under the headline “Should we… Colonise other planets?”