Let's go to Mars, but make sure it's for the right reasons

By Bob McDonald, Quirks and Quarks

A new report from the US National Research Council on Spaceflight recommends a more realistic approach to sending humans to  Mars, including the rationale that going there, "ensures the survival of the human species through off-Earth settlement." 

That is the last reason we should explore other worlds.

This sentiment, that Mars could be the place where humans can move if conditions on Earth become inhospitable, has been echoed by NASA Chief Charles Bolden and Elon Musk, founder of SpaceX,  the private company that unveiled its new Dragon2 Capsule to carry astronauts to the International Space Station. It also has plans to develop an inexpensive delivery system to the Red Planet.

Despite the images of red deserts, pink skies, deep canyons and towering volcanoes sent back by robotic spacecraft, the one thing the images don't convey is how cold and un-hospitable Mars actually is. 

We tend to think of sandy deserts as hot places, such as the Sahara or American Southwest. But since Mars is farther from the sun than the Earth, temperatures across its dusty plains seldom climb above zero degrees Celsius. In deep valleys along the equator during the summer, the thermometer might rise to 15C for short periods, but it will plummet to -70C at night. 

Most of the planet is well below freezing permanently, with the Polar Regions cold enough to produce frozen carbon dioxide snow ... dry ice.

The atmosphere on Mars is almost entirely carbon dioxide with virtually no oxygen, so spacesuits are required. The air is so thin - the equivalent of being above 100,000 feet in the Earth's atmosphere - it doesn't hold heat very well, so even if it is a warm day the balmy temperatures would only be felt by your feet. The top of your head would be frosty. 

There is also no ozone layer to filter deadly UV radiation from the sun, nor is there a strong magnetic field to shield from the solar wind, so excursions on the surface would have to be limited.

In other words, the surface of Mars is a nasty place, more like the South Pole than the Sahara. 

There are lots of reasons to explore Mars, and a small group of intrepid explorers will one day set foot on the Red Planet, perhaps eventually establishing a colony there. But it will not become the new promised land, the way North America was to Europeans half a millennium ago. 

Living on Mars is harsh, with few natural resources available. Homesteaders will not be faced with dense forests, clear rivers and abundant wildlife to start a new life. 

About all Mars can offer are minerals, rocks that contain oxygen, and underground ice. No one even knows if Martian soil could support plants in a greenhouse. And if you run out of supplies, the delivery truck takes seven months to get there, at a cost of at least a billion dollars.

Of course, it might be possible to geo-engineer Mars to replenish its atmosphere and make its rivers flow once again, but this would take tremendous effort with no guarantee of success.

To think that this hostile world could ensure the survival of humanity is ridiculous, when you consider what an oasis of life the Earth is. Why would we give up living in the Garden of Eden to move to a frozen hell?    

The biggest lesson we have learned by going to other worlds is how rare the Earth is. From the first images of the blue marble taken by Apollo astronauts from the far side of the moon, to the pale blue dot seen from the far side of the solar system, our little planet is turning out to be the only oasis we know of in a vast, hostile universe. 

All the other planets in our solar system, plus the nearly 1000 discovered around other stars, are all interesting, but deadly. When we do find another Earth equivalent somewhere out there, it will be so far away it will be unreachable.

So, sure, let's go to Mars. In fact, I will volunteer to make the first boot prints in the red soil. But like any traveller in a strange new place, I will think about what I left behind and be happy to return home. 

Let's go to other worlds to discover the nature of planets, so we can appreciate our own and learn better ways to protect it. Let's not use Mars as a reason to think of the Earth as disposable.