The question of whether life exists on Mars has been debated for decades, and the discussion continues today. Bolstered by the recent discovery that there's actually a 12-mile body of water under an ice cap Mars' south pole, scientists are beginning to wonder if there might really be some kind of bacterial life on the Red Planet.
But believe it or not, Mars may have been more friendly to life many, many years ago than it is today.
Researchers have discovered areas on the planet's surface that indicate that Mars may have once had the right atmosphere to support liquid water, including finding areas that appear to by long-dried riverbeds or mineral deposits that could not have formed without liquid water. It's some parts speculation, but astronomers continue to look for more clues into the Martian past.
What's indisputable, though, is that the Mars that we see today can't support liquid water on the surface. Why? Again, there's a lot of ongoing research into that particular question, but prevailing theories suggest that it's due to asteroid collisions causing Mars to lose chunks of atmosphere, in addition to strong solar winds, against which Mars has no protection (such as Earth's magnetosphere). Over time, these factors essentially sapped Mars of its atmosphere, meaning that it no longer had the right pressure for liquid water on the surface.
But could we make Mars livable again? Martian colonies have been mankind's dream for a while now, but with the conditions on the surface, any colonists brave enough to relocate would be subjected to a life of spacesuits and powdered food. What if we could fix this by making Mars more like Earth--i.e., terraform it to our needs?
What would Mars need to make it like Earth? Quite literally, an act of God--but there are a few things within conceivable reach that would make it comfortable, at the very least. Primarily, it would require playing with the atmosphere to get it to both a livable temperature (the average temp on Mars is estimated to be -67 degrees Fahrenheit) and a pressure that supports liquid water. Sounds easy enough, right?
Here's the problem. To get it to ideal conditions, Mars' atmosphere would need a pressure of 1 bar (equal to the Earth's), and would need enough greenhouse gas to trap heat from the sun. Currently, the pressure on the surface of Mars is approximately 6 millibars, so we're talking a 166x multiplication of pressure here. Still, that's doable, as long as there's enough carbon dioxide on the surface of Mars.
A new study, though, says that there probably isn't enough on Mars to do that. Using data from satellites orbiting the Red Planet, planetary scientist Bruce Jakosky says that, at most, you could probably scrape enough resources from the planet itself to result in a pressure of "40 or 50 millibars," WIRED reports. That's pretty much nothing, and Jakosky says that amount of gas would "probably push [the temperature and pressure] up by a factor of two or three, but even that doesn't get you anywhere near the amount required to produce significant warming."
There is still some hope though, for all you enterprising future Mars colonists out there. Astrobiologist Christopher McKay says that what's really important is the "amount of CO2, H20 [water], and N2 [nitrogen] on Mars." He's right--carbon dioxide alone wouldn't even get the planet over 32 degrees Fahrenheit. Plus, he says, "we are still highly uncertain as to the amount of CO2 below the surface." That's because the satellites providing the aforementioned data have been focused on Mars' poles, so the data they collected may not be indicative of the entire planet's makeup.
So, scientists may not have concrete numbers on carbon dioxide yet. But according to Mars terraforming optimists, we could even use other mixes of greenhouse gases to achieve the results we want--a riskier proposition and not necessarily feasible for now, as it risks blowing out the thin layer of ozone in the Martian atmosphere.
All of it to say, we might be better off sticking with Mother Earth a little while. And it didn't work in Star Trek, so that's good enough for me, at least.
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I'm a sci-fi/fantasy lover & writer who especially likes talking about Star Wars and futuristic tech. I like finding new things & finding the beauty in old things, especially in my "Everyday Snippets" series. I hope you'll join me on my blog and unleash your imagination!