Mad About Science: The Earth and Mars

By Brenden Bobby
From the Sandpoint Library
Reader Columnist

We haven’t talked about the planets in a while, so they’re getting restless and are in desperate need of the limelight. The planets can be such divas, especially Pluto. But we’re not talking about Pluto, right now. We’re going to talk about Earth and Mars.

Earth: From our vantage point, it seems pretty mundane. There’s the coffee shop, there’s work, drive there in my car, come home and get a beer. I know Earth. Stop and think about it for a moment, though. As far as we’re aware, we’re the only planet in this system that has life of any kind. We are most definitely the only intelligent life of any kind in our system. There are countless things on our mundane rock that we’re so used to that isn’t even possible in most places in the galaxy.

That coffee shop? Built by wood that came from trees that spent millions of years reproducing, spreading, and changing over many generations. Your car, whether it’s nice or a real clunker is an astounding feat of engineering. Metal pulled from the Earth, heated, bent and shaped to perform a very specific, yet versatile task. Your beer, made from hops that, in all likelihood, had their evolutionary future modified and bent by human will and selective reproduction under highly controlled conditions. You’d be hard pressed (literally) to find that on Venus..

Why is Earth the way it is? Honestly, we’re not entirely sure. Whatever the case, there’s a key ingredient at the center of it: liquid water. All life we’ve ever observed thrives on and requires it. A key part of that equation is oxygen. Oxygen is supremely important for life as it exists now on Earth. If you don’t believe me, try holding your breath and prove me wrong.

That key element almost didn’t occur in such prevalence on Earth. Instead, had things gone a little differently, life may have evolved in unexpected ways, or not at all. When life first dawned and ruled the planet for at least a billion years (possibly up to 3 billion), they were simple little microbes that loved carbon dioxide. Oh yeah, the planet was covered in the stuff, tons of it. The planet probably flew into countless global climate changes until some of these microbes figured out a way to start pulling energy from the sun. It was evolution in its simplest form. However, this came with a unique effect that would forever change the history of life on Earth. While harnessing the power of photosynthesis, these microbes separated the carbon and the oxygen. This was such an efficient process that they were able to start reproducing more quickly than their competition. Over time, the CO2 in the atmosphere was replaced by oxygen, and these little guys literally suffocated their competition, which allowed for the evolution and spread of what would (much, much) later become multicellular organisms.

There is nothing mundane about Earth. We are truly a unique world, as far as we can tell.

Our next door neighbor is pretty interesting, too: Mars, the red planet. Despite being neighbors, Mars is pretty far away. On average, Mars is 225 million kilometers (139 million miles) away from Earth. When they are both in opposition of one another, this number nearly doubles.

The first thing you notice when you look at Mars is that everything, and I mean everything, is red. That’s because iron particles exist within the dust on the surface. There is a lot of this dust—it’s literally everywhere on Mars. The iron reacted with the oxygen in the atmosphere and it rusted, turning it red. Now, storms hurl the dust all over the place, break it up even further and stain the sky red, too.

So what’s the fuss about water on Mars?

Water, in its liquid form, is important, as we found out from our continued existence on this planet. Finding liquid water brings the distinct opportunity to find things living in the water, and when we find things living in the water on other planets, it’s sort of a huge deal; it would prove that we’re not a one-of-a-kind accident, that life is able to and has sprung up on other worlds than our own. We’ve proven that, at one point, Mars had liquid water from the channels carved throughout the planet’s surface. Most of it’s gone now, though.

Where did the water go?

At one point, Mars underwent a process we’re seeing happen on Earth now. Mars’ atmosphere was either stripped away over time, or stripped away very suddenly, leaving it with more CO2 than oxygen. Oxygen is a great deflector of heat, while CO2 is kind of like holding a magnifying glass over an ant. Sound familiar?

Essentially, with the sun being able to freely peek on through the atmosphere, the water evaporated into hydrogen and oxygen. Then the sun’s solar winds just whipped them right off the surface and into space. Mars’ water literally got blown into the abyss.

Hopefully you learned something about one of these planets today. Hopefully we’ll all study the hard lesson of our neighbor Mars. I like water. It lets me eat tacos, and I like tacos.