When we think of the word aerobic, our mind is drawn to the sight of sweaty people, in neon tights, dancing chaotically in a class led by an instructor; likely at a gym.
But what it really means, is the type of movement that generates a great amount of breathing…usually heavy, if you’re as out of shape as I am.
Aerobic respiration, the kind that relies on oxygen, is the process in which cells take in oxygen and then break it down to produce energy in order to drive metabolism. That’s why those neon clad classes are so beneficial for getting in shape. This type of respiration is necessary for most life here on Earth.
And yet, life as we know it doesn’t always need oxygen.
In fact, the earliest organisms to develop on Earth were anaerobic; meaning they were able to survive without free oxygen. This type of life still thrives on Earth today in modern microbial diversity.
However, because oxygen is such a great source of energy, its availability makes for many possible evolutionary pathways that have given rise to more complex plant and animal life. Because of this, oxygen is a key ingredient when determining the potential habitability of any environment.
And while oxygen is abundant on our home planet, it is relatively scarce on Mars.
Back in July of this year, scientists reported having found a subterranean reservoir of potentially liquid water near the southern polar region of Mars. It’s thought that this underground lake is likely composed of salt water. If the briny water does, in fact, exist below the Martian surface, it could potentially have enough oxygen molecules to support life.
The reason for this belief is because colder temperatures promote greater oxygen absorption into the brines here on Earth. If true on Mars, this raises the potential for oxygen-rich water to be able to support complex multicellular organisms like the sponges we see in our own oceans.
NASA’s Curiosity rover recently identified rocks that are rich in an element known as Manganese. Here on Earth, Manganese deposits are closely associated with life. Briny water that bubbles to the surface on Mars may have been interacting with rocks over millions of years, forming the Manganese-rich deposits.
This interaction could still be going on, eliminating the need for Mars to have once housed an Earth-like atmosphere or oceans.
It’s still too early to make assumptions, however, since here on Earth, it takes a lot of dissolved oxygen to produce these types of minerals. Manganese Oxides formed on Earth during the Great Oxygenation Event 2.5 billion years ago when O2 began persisting in the atmosphere.
Absorbing water vapor from Mars’ atmosphere to make the brine in the first place, in a process known as Deliquescence, would be difficult for salts near the surface.
Some scientists believe it is more likely that brines form as subsurface water meets salt-rich minerals already in the soil. These interactions can happen deep beneath the surface where groundwater can dissolve the rocks over billions of years.
If briny deposits exist in more areas than just the polar regions, this could be bad news for any future missions, especially manned ones. Currently, planetary protection protocols require strict decontamination methods for any landers inspecting areas that may have the potential for life.
This prevents accidental extinction or contamination of any life that may already exist. In addition, the protocols are meant to prevent microbes from other worlds from reaching Earth on future sample-return missions. This would be difficult, if not impossible, to do on a manned mission. So, more research is warranted before sending a colony to the Red Planet.
Still, as Vlad Stamenković, lead author of the study published Monday in Nature Geoscience, states, “We live in exciting times. Especially as there is so much more work still needed to better understand the Martian habitability. I hope this creates excitement in the [scientific] community, in the world, to think of Mars as a potential place for life to exist maybe even today.”