I’d say it’s the opposite actually. We do protect species on Earth now. By considering human landings on Mars at all when we have the possibility of a crash that would introduce Earth life to Mars irreversibly - they are taking less care than they would e.g. if they wanted to send a submarine into lake Vostok in Antarctica. There is no need to do it this way. We can make it our opportunity to do things right this time around - both on Mars and on Earth.

They agree that potentially it’s an irreversible change, if you introduce life there through human missions to Mars. But if you follow through the consequences of what that means - the results would be that if there are habitats there that Earth life can reach - spread in the Mars dust storms - then not only us, also none of our descendants, will be able to study Mars as it is now without the introduced Earth life. No future civilizations that arise in our solar system will be able to do that either. If it was reversible, fine, but extinction is for ever. This is for an entire planet too.

I think we should send humans to the Moon and to Mars orbit first, and make Mars orbit our long term destination, not the surface. Also Mercury, Venus, Jupiter’s Callisto, many other places, but let’s leave off sending humans to the Mars surface until we understand it better.

As you can see, the Russians drilled all except the last few meters, and then they waited while they figured out how to do the last bit without contaminating lake Vostok with the drilling fluids and with surface life.

You wouldn’t be permitted to take a human occupied submarine into this lake, not yet anyway, because it has been isolated from the surface for millions of years. Scientists want to be able to study whatever life is there without contaminating it with life from the surface first.

Yet they are considering sending humans to the Mars surface, and want to do that before we have any chance to do anything like a reasonable survey of the planet with robots first. There are many potential habitats on the surface now known, see for instance Does Ice Act As Greenhouse On Mars - Fresh Liquid Water Habitats In Spring 10-20 Cms Below Polar Ice? for a striking rarely reported possibility. Their plan is to send humans to the surface long before we have a chance to study any of those habitats close up uncontaminated. How can that be right?

With Mars we have a chance to get it right. We have already made many species extinct on Earth. Back at the time that we made the Dodo and then the Passenger pigeon extinct, then nobody had even given it much thought. The extinction of the passenger pigeon was something of a wake up call.

However we have changed. If we’d kept our nineteenth century attitudes, then the blue whale would certainly be extinct by now, and many other species. A large part of our population does care about such things now. And we are managing to save species here too.

In the case of Mars then - it’s not species of microbes only. We have no idea what is there but it could be entire new realms of life.

Microbes yes, but extra terrestrial microbes that are not even based on DNA. Or their last common ancestor was billions of years ago. The most recent common ancestor would be at least 66 million years ago probably, because you need an impact on Earth large enough to send material through our thick atmosphere with sufficient speed to escape Earth’s gravity - like the Apollo spacecraft - and to travel all the way to Mars.

But not only that, the life has to be able to survive shock of ejection and impact, a century in vacuum and extreme cold, bombarded by cosmic radiation and solar storms, and when it gets to Mars it has to be able to survive in the inhospitable environment there. Also if it is the first lifeform to get there, it has to survive as a single species ecosystem. It’s not easy. Maybe it has happened, maybe it never has.

What we find on Mars could be a completely different form of life, or it could be that it is an earlier form of life, made extinct on Earth, it could even have evolved further than Earth based life in the harsh environment there (though probably still microbial or at most lichens).

At any rate Mars is surely much more isolated from Earth than anywhere here, even lake Vostok.

For more about this, see my

• President Obama, Why Humans On Mars Right Now Are Bad For Science
• New President - Pivot To Moon On Way To Mars? Lunar Spelunking & Science Surprises
• Why Spacecraft Crash On Mars
• Mars Is Nothing Like The New World - Easier To Grow Your Tomatoes On Mount Everest
• An Astronaut Gardener On The Moon - Summits Of Sunlight And Vast Lunar Caves In Low Gravity
• Earth best for a backup
• No rush to send humans to Mars