Geo016 - Exploration of Mars

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Geo016 / Exploration of Mars / (M) 3:00-5:20 / Lincoln Field 105 / Prof. James Head

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Lillian Ostrach (03/10/04)

In “The Iceball” article, by Stephen Clifford, he discusses the need to “follow the water” on Mars since water is one of the requirements needed for life that we know of at this time. The surface of Mars shows evidence of liquid water at one time, however, the water has somehow “disappeared,” and this disappearance is not yet understood. With the overview of Mars in terms of its place in the Solar System and explanation of its geological history during seminar on Monday, the absence of apparent water still remains at the forefront of unexplained and unanswerable questions. It is necessary to continue consideration of the geological history of Mars, as well as the geological processes operating on the planet, in order to potentially “follow the water.”

The landscape of Mars is riddled with clues as to its history, unlike that of Earth. The absence of tectonic plates gives rise to a definite timeline and ability for researchers with the proper equipment to date geological landmarks and discover relative ages of craters, lava flows, volcanoes, and scarp. Moreover, the impact craters on the surface of Mars provide information as to the age of its surface, in addition to allow us to compare it to other planets, such as the Moon and Mercury, to gain a better knowledge of its planetary history. The impact craters on these three planets help to define the global planetary processes which occurred in the first half of the Solar System history, a history lost to the Earth because of the shifting tectonic plates. On Mars, the impact craters provide a means of potentially discovering when liquid water existed on Mars, in addition to the age of the surface relative to volcanic lava flows and other geological events. While many of the geological processes on Mars are different than on Earth, many can also be compared to Earth in order to get a better idea of geological history. For instance, Olympus Mons is 25km high, almost 3-4 times as tall as Mount Everest, which is ~8.8km tall, and much larger across. The Valles Marineris covers an area measuring the distance from Boston to Los Angeles. Additionally, the Outflow Channels and Valley Networks exhibit characteristics similar to comparable geological finds on Earth. Indeed, it is interesting to realize that it seems as though the geology of Mars is similar to Earth, but on a much grander scale. This is most likely due to the decreased gravity and lack of plate tectonics on Mars, however, we cannot be completely sure. Moreover, many of these landmarks on Mars' surface exhibit water traces. It is known that under the present conditions, liquid water cannot exist on Mars because the temperatures are so cold. With no clue where water exists at the present time, besides that in the polar ice caps, many extrapolations are being made: a common one is that the water has frozen under the surface in the Northern Plains.

With this question of “where did the water go?,” it follows that the question next presented is, “what about life?.” In Gerald A. Soffen's article, “Life in the Solar System,” he presents the idea that there is no universal agreement on an exact definition of what life is. We know that, on Earth, terrestrial life has two main characteristics: its ability to reproduce and its ability of evolution through natural selection and genetic variety. Additionally, on Earth, life requires three things: water, energy, and access to organic materials. Furthermore, when organisms on Earth are considered, life is composed of hydrogen, carbon, and nitrogen, three of the most abundant elements of the cosmos. So what exactly is life? It is daft to think that life could have evolved in a single way, that life requires oxygen and another set of specific elements, especially since chemosynthetic organisms have been discovered surviving near the deep-sea vents.

As Soffen described, the failure of the Viking missions to find life on Mars spurred scientists to investigate with greater detail the question of life in the Solar System, beginning with life on Earth. Every day, new species of organisms are being discovered, and identified species are becoming extinct. We have not classified as much as half the life forms existing on our planet, so how are we able to definitely determine whether life exists on another planet when we do not find signs of obvious life? I think that the search for life is similar to a math equation—specifically a differential equation. For mathematicians, differential equations are about getting lucky as opposed to being clever, however, when solving a differential equation, certain steps are taken. If these steps do not work or lead to an empty answer, they start over and use a different approach. This system is worthwhile because, hopefully, the differential equation will either be solved using a specific approach, or the possible approaches will be exhausted without a definite mathematical answer. In any case, either of the two options will yield conclusive results: the math problem can be solved or it can't. It is stupid for us to believe that we know the certain conditions, exactly, under which life can or cannot exist. The fact that we haven't even discovered all of the life on our own planet attests to this. How can we say that, because we haven't yet found traces of life on Mars that it doesn't exist? For many years we had no clue that chemosynthetic organisms existed in the deep sea, and the discovery of these organisms opened up a new door into the issue of biological diversity. It is entirely possible that life can exist using other elements than those we know work on Earth. We just need to approach the experimentation differently. Miller and Urey produced amino acids and sugars in 1953 by exposing methane, ammonia, and water to electrical excitation. Amino acids and sugars are the bases of biological processes, and certain combinations of these molecules and other elements and conditions have the potential to create life. This experiment did not involve oxygen, which proves that chemical interactions can be created under different circumstances. This only goes to show that it is possible life can exist without oxygen and under different chemical compositions.

Moreover, the ALH84001 meteorite was found to have “biological” elements from Mars embedded in the rock. While many scientists dispute the evidence and state that the length of time it spent in the Antarctic contaminated it, it is quite possible that other meteorites from the outer reaches of the Solar System have similar finds. During the early evolution of our Solar System, planetesimals and meteorites frequently impacted the planets. As Soffen discusses, the impacting objects delivered water and a rich assortment of organic materials to Earth. If comets and asteroids could deliver these substances to Earth, it is highly likely that they delivered them to other places in the Solar System. Furthermore, the question remains where these meteorites originated from. It is possible that an impact on say, Mars, could have created a piece of flying planet that impacted Earth…with organic materials. Could we have originated from another planet? The fact that organic material has been found on meteorites proves that there is an interstellar link between Earth and the cosmos. What if the primordial soup of organic matter and biological processes was spurred by the impact of a meteorite from Mars, or Mercury, or by another star system? There is much circumstantial evidence that, because of the existence of organic material in meteorites, life could be based on chemistries of organic compounds well before the chemicals on Earth had formed, and as a result, the search for life elsewhere, no matter how primitive, has a high chance of being successful.

This vein of thought, with respect to different life forms and the implications of different geological formation was continued at Bliny Night by many of the students I ate bliny with, however, we talked more about the recent discoveries on Mars by Opportunity and Spirit. The ability of the rovers to do so much is incredible, and the pictures and data transmitted back from Mars is mind-boggling. Other students agreed that the detail and magnificence of the landscapes as captured by the rover cameras is incredible. We got into a discussion regarding human versus automated space exploration. The prevalent belief was that human space exploration is necessary, however, all automated space exploration should be explored before sending humans to distant places. Many agreed that, while risks will always exist for human space explorers, whatever machines can do to decrease the risk is worthwhile, even if it means spending trillions more dollars and taking more time to do so.

The cost of human lives is high, and I personally feel that human intelligence should not be wasted. If there is a job that a rover can do on Mars that could increase our knowledge about the planet and help decrease risks associated with human space travel, I say go for it. It makes no sense to me to train astronauts for a journey to their deaths—although that can happen and cannot be forgotten. However, such instances of tragedy should be limited, if not eradicated (this isn't possible—there can ALWAYS be an equipment malfunction even if the machinery has been tested and re-tested). For instance, if the Federal Government had funded the Space Program more adequately, it is possible that the Columbia disaster could have been prevented…However, that is another story and I am not placing blame on anyone. Instead, the tragedy should never have happened in the first place. The loss of such brilliant scientists affected many, and such disasters should not occur. Thus, automated exploration is necessary until all potential risks have been identified and methods to decrease such risks are implemented.

Speaking with Dr. Krushchev about this, in addition to his thoughts about Bush's initiative and program, was eye-opening. I greatly appreciated the chance to talk with him in an informal environment. I will remember forever what he said when Kate asked him what he thought of Bush: “…Bush is a lot like Yeltsin, but not as drunk, so he doesn't have an excuse.” Not believing that Bush's initiative is a political move, Kruschev said that Bush is just like a little boy, grabbing at the stars like candy, trying to get a grasp on a deserted dream, in fact, that he was doing it for himself. I thought this very intriguing and quite possible. After all, it's taken Bush four years to begin to sufficiently fund the Space Program, and only after his war with Iraq has been exhausted and our economy going down the tubes…what exactly does that say about our President?
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