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Obviously, to find life on Mars, we need to understand how to look for it! As an exercise in searching for life, my colleagues and I were asked to complete a two-part assignment. We first completed a chart and definition listing the fundamental criteria for life, which you can view here. Next, we looked at 3 samples of "Martian soil" under a microscope, the first time without water added and the second time with water added. We observed the changes between the two samples and kept records of what we saw. To the left, you can see those records, and below you can read the post-lab Q&A. Our Definition of Life: Things that are alive are animated, can move on their own (Internally or externally), are carbon based life form, can reproduce, needs water, nutrients, and space, and animals need oxygen, while plants need carbon dioxide (unless they are at a hydrothermal vent). 1) Which samples showed changes after the water was added? Samples B and C were the only two samples that showed (noticeable) change. 2) Can you use your definition of Life to determine if the changes were the result of life or simply a chemical reaction? I don't really think so. Our definition certainly explains what life is, but when you're looking at two unclear microscopic samples, both of which could possibly contain life, it's hard to tell if whatever's in there is able to "reproduce" or not. I guess one could argue that we could look for something animated in the samples, but animation isn't always a surefire sign of life. As this lesson is trying to explain, it could simply just be a chemical reaction. I'd say that our best bet for discovering life is to look for something dormant that could have changed after water was applied to it, rather than something that suddenly appeared. If there was microscopic life somewhere in one of samples, we probably would have seen it before the water was added. 3) One sample contained a chemical that reacts to water, another sample contained a living microbe that caused a change, how can scientists tell the difference between a chemical change and a life process that causes a chemical change? Truly, I don't exactly have the best idea. Even Google doesn't have any answers for me! All I can say for differentiating the two is that under a microscope, I would assume that life could always be seen, regardless of whether or not something had been added to the sample. This is why I think Sample C is the one containing life. Beforehand, we could see something strange inside the sample. One of my colleagues thought that the small, claylike pellets were yeast, and that's entirely possible. Once the water was added, the pellets seemed to transform into something entirely different. I wouldn't be surprised if the white pellets were, in fact, some microscopic organism in its dehydrated form. Once water was applied to it, it sprang back to life, similar to how a tardigrade can. When it comes to a chemical reaction, it seems unlikely that we would see some item in the sample that could possibly be life, but I'm not sure. Maybe I'll come up with a better explanation later, when I can actually focus. |
For years, Mars and have been the subject of many works of pop culture, as shown above in the Imaginary Martians section. Below that, we learned what actual life on Mars might be like, and how to look for. Now, onto our final Is There Life On Mars? mission critical objective, creating a creature that could, theoretically, live on Mars. Using the knowledge of Mars we've collected throughout this project, and a healthy dose of creativity, us science officers were asked to design a creature that could, maybe, inhabit the harsh environment of Mars. Read below to learn everything you need to know about SARCC's theoretical Mars Critter.
Description & Questions: 1) The critter's name: The Mars Rooster-head Redback 2) Describe the habitat and climate in which your critter lives: The Redback is sure to live near slopes where water contemporarily flows so that it can always have access to something to drink. It's only active during Mars' warmest months, when water actively flows. For the rest of the year, the Redback stays in its dehydrated state. 3)How does it move? Include both the form and method of locomotion. (For example: The miniature Mars Gopher leaps on powerful hind legs.) The Redback moves sort of like a lynx, balancing on its large paws. The absence of a tail or front paws purely made for balance can make it a little clumsy at times, but Redback pups are trained to traverse the rocky surface of Mars from a young age. 4) What does it eat or use as nutrients? Is it herbivorous, carnivorous, omnivorous, or other? What is its main food, and how does it acquire this food? When it comes to a diet, the Redback lives purely off of bacteria. There is evidence that at least one time, there was bacteria alive on Mars. Though there is no firm evidence that there is still microscopic life on Mars today, if this creature were to exist, that is, theoretically, what it would eat. Though bacteria is alive, it is considered a prokaryote, a cell that lacks a defined nucleus. This sets it apart from being simply a plant or animal. So when it comes to whether the Rooster-head Redback is considered, say, a carnivore, I'm not sure, seeing that it only eats prokaryotes. Though its jaw may look very defined, it actually is not. Using its flexible muzzle, the Rooster-head is able to "suck in" bacteria from within the air or water. The bacteria either directly enters its digestive system, or gets stuck in thin sheets of tissue in the mouth, where it can be eaten later. 5) What creatures does it prey on, if any? How does it defend itself against predators? As stated above, the Redback lives entirely off of bacteria it catches. Though no evidence of any predators has been uncovered (as of now), the Redback seems to possess traits that could help defend against any threats. First off, the Redback is, well, red. Its body, especially its back scales, have a distinctive red/orange color that helps it camouflage with Mars' dusty surface. If a predator is nearby, the Redback can use its scales to blend in with its surroundings and hopefully be overlooked by the predator. The Rooster-head Redback also possess another defense mechanism. Like an armadillo, it can curl up into a tiny ball, so that its vulnerable underbelly will not be exposed. This is the same form it assumes when entering its dehydrated state. 6) How does your creature cope with Mars' extreme cold, unfiltered solar radiation, and other environmental factors? Besides maybe a tardigrade, there is no creature on Earth that could really survive on another planet in our solar system. The conditions are just too extreme. So, when trying to design a creature that could actually live on Mars, I encountered many factors it would need to face. First of all, there isn't exactly oxygen on Mars. Luckily, there's evidence that right here on Earth, multi-celled creatures can live without it. Instead of possessing mitochondria, which turns oxygen into energy for creatures like us humans, the Rooster-head Redback has hydrogenosomes, which give it energy without using any oxygen at all. Multi-celled creatures that possess hydrogenosomes have already been discovered on Earth, so who says they can't work for a larger creature on Mars? However, the Redback's main survival technique is making use of its dehydrated form. Like the tardigrade, infamous for its extreme resilience against forces like the ones it could encounter in space, the Redback can enter a death-like, dehydrated state for years at a time. Usually, the Redback stays curled up in its dehydrated form until Mars reaches its warmest months, and water begins to flow across its surface. Until then, it remains pretty much dead. In this dehydrated form, it can resist Mars' extreme temperatures, unfiltered solar radiation, and the powerful vacuum of space. For the brief time that it is awake, the Redback is usually able to regulate its body heat (to a temperature high above what a human's is regulated to) so that it can stay warm in Mars' freezing temperatures. 7) Is it solitary or does it live in large groups? Describe its social behaviors. Generally, the Rooster-head Redback travels in small family groups. These groups usually consist of only two parents, and one to two offspring. Redbacks usually live with their parents until they reach sexual maturity, when they then leave the pack to search for a mate and begin a new family group. Both parents equally balance their responsibilities for caring for their offspring, and mate for life. Usually, one couple will only be able to produce about two pups, seeing that females must wait a long time before they are ready to give birth to another pup. Though Redbacks usually don't move around too much, they are very territorial, and the rare encounters between packs can get aggressive quickly. If a young Redback approaches an already-established family group looking to mate with one of the offspring, they must first challenge their potential-mate's parents to prove themselves worthy. Female Redbacks challenge the head female, and male Redbacks challenge the head male. If the foreign Redback is able to defeat one of the pack leaders, they are accepted by the pack and allowed to take one of its members as their mate. If they fail, the pack has the authority to either chase them away from their territory, or, in some cases, kill them. Finding a mate as a Rooster-head Redback is truly a high-stakes game. 8) What else would you like others to know about your critter?
Now, read below for information about how we will use our Mars rover, Prometheus, to actually search for life on Mars. |
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When designing Prometheus, some the first features we were sure to add were ones that would give it the ability to help us search for extraterrestrial life. There's quite the potential when it comes to life on Mars, and equipped with new technology, we're more prepared than ever to explore that possibility. Prometheus is equipped with many helpful features such as a weather station and moving camera, but the main features I would like to focus on are the ones designed to look for life. Using a robotic arm, Prometheus will be able to collect samples of Martian soil similar to the ones we used while completing our second mission critical objective. From there, it can either observe the sample and take pictures on-site using its built-in microscope, or bring them back to the SARCC lab to be analyzed. Hopefully, in our time away, we will be able to discover life on the Red Planet. Once we finally set up shop on Mars, Prometheus will be ready to go and do what it does best: Look for life!
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