On Saturday, May 5, NASA is launching its newest Mars lander. The Mars InSight lander is set to arrive at Mars in November. This spacecraft is a first of its kind because it will be launched from the West Coast unlike other launches to Mars. More importantly, however, this lander is unique because it will attempt to peer beneath the surface of Mars; past rovers have only been able to explore their surroundings and at most collect samples and drill into the topsoil. Unlike the past rovers, the InSight lander will stay still, rather than moving around Mars’s surface, so that it can measure the internal properties of Mars. One thing the Insight lander is set to look for is marsquakes, or seismic activity on Mars. Earthquakes on Earth are caused by plate tectonics, whereas marsquakes are caused by volcanism. When a marsquake occurs, the InSight will be able to take a picture of Mars’s interior for astronomers on Earth to see. The goal is that greater study of Mars’s interior will be able to give us more insight into how Mars was formed. We have a general idea about how rocky terrestrial planets like Mars were formed, but we would like to learn more about how Mars came to be the cold, geologically dead world it is today.
Some of the information to be gathered includes the thickness of Mars’s crust and the composition of its mantle and core. In particular, three main experiments will be conducted by InSight. The Seismic Experiment for Interior Structure will track marsquakes and internal activity. This will tell us more about Mars’s history and structure. The Heat Flow and Physical Properties Package will measure the movement of heat under Mars’s surface. This will tell us more about how Mars’s interior has evolved over time. The Rotation and Interior Structure Experiment will use radio signals to detect rotational wobbles. This will tell us more about the properties of the core and the interaction between the core and the mantle. It is the hope of scientists that with the results from this mission, we will be able to better understand how and why Mars formed the way it did and what it would take for worlds similar to Mars to form, whether they be terrestrial worlds in our own solar system or even exoplanets in other star systems. Fascinatingly enough, these studies of Mars’s interior will help the scientific community learn about planetary formation and evolution that extends beyond our own solar neighborhood!
Many people think about our future of exploring the solar system and perhaps nearby star systems and imagine finding bacterial life or perhaps even fossils or ruins of life that has gone extinct. While this would imply that life exists much more plentifully than expected across our galaxy, it might not actually bode well for the future of humanity.
A visual representation of the Great Filter stopping nearly all developing civilizations.
A caveat to Fermi’s Paradox is often referred to as The Great Filter. This theory suggests that the reason we have no evidence of life outside of our own planet is that there is some obstacle to becoming a galaxy-spanning species which is virtually insurmountable. These obstacles can generally be thought of as the elements of Drake’s Equation. In other words, one of the elements of the equation such as the probability of life becoming intelligent is essentially zero.
Applying this concept to our future exploration, finding the ruins of some other civilization might imply that our species is destined for a very similar fate. Finding fossils of less advanced life, on the other hand, might actually bode well for our eventual colonization of the stars near our home.
Hypoliths are photosynthetic bacteria that inhabit the desert. Despite the Namib desert in Namibia being one of the most extreme environments on Earth, hypoliths thrive under quartz rock under these harsh conditions. This desert can go years without rain and it is subject to constant solar radiation and scorching heat. With very little water and no trees or shrubs in sight, the fact that this desert has life at all is amazing. Living under the rocks protects the hypoliths from ultraviolet radiation and wind scouring. The rocks are also translucent, allowing light to penetrate, and trap moisture. What hypoliths and other extremophiles can tell us is where to look and where not to look for life on other planets. Mars may be cold, but it features a desert environment that is also subject to brutal solar radiation. Therefore, Mars may be a good place to look for bacterial life.
We may not find quartz rock on Mars, but if we wanted to find life, we may look for areas in which only a certain amount of light can infiltrate, which would create hospitable conditions for life. Although it’s probably best not to interfere with the natural environments of other planets, it would be interesting to see if hypoliths or other extremophiles would be able to survive on Mars or other planets if we were to deposit colonies there. Out of anything we have here on Earth, extremophiles give us the most insight about the possibility of extraterrestrial life, so I hope further research into them continues to teach us more about what may be out there in our expansive universe.
You’ve probably heard of the name Hubble before. “Hey, isn’t that that big telescope that’s out in space taking pictures of the universe?” And, you would be right if you did ask such a question. But, like many things that are named and sent to space, these names have a meaning. The history of the name Hubble in our modern world begun with one man, just like you and me, called Edwin Hubble.
Hubble was a noble man. As a WWI veteran who was born in Missouri, he simply went on to pursue his passions. His fate with physics, however, was not coincidence, as he earned a full scholarship to the University of Chicago and worked on Robert Milikan, who would later go on to win the Nobel Prize for his quantization of the electron via his oil-drop experiment. Surprisingly, Hubble ended up graduating from the University of Chicago with a degree in Jurisprudence. For the 99.9% of people who are unsure of what this degree is, it is simply a degree in the philosophy of law. Despite this, Hubble returned to the university to get a degree in astronomy and was later recruited to be part California’s Mount Wilson Observatory.
It was in this observatory that, while studying galaxies Hubble noticed something interesting. Hubble discovered that galaxies were moving away from each other. But, this movement was not random at all, but instead at a linear rate. Let me explain this by using arbitrary terms. Let’s say that there is a galaxy called “A” that is x kilometers away from us. Now, let’s say there is a galaxy “B” that is 2x kilometers away from us. x can be any value, but it’s value does not matter. What does matter is the fact that B is 2 times further away from us than A is. Therefore, since B is two times further away than A is it will appear to be moving away from us twice as fast as galaxy A is moving away from us. Edwin Hubble and his colleagues published this data, resulting in a revolutionary look at space and the universe itself.
From this data we get the Hubble Law. Hubble’s Law simply states that the further away something is in space the faster it will appear to be moving away from us. From this we also derive the Hubble constant, which is this constant rate at which recessional velocity seems to increase as distance increases. Note, however, that this regards things not in our solar system that we are gravitationally locked to. This means that other things in our solar system, like the Sun and the planets, as well as other things in our galaxy, will not appear to be moving away from us because we are gravitationally locked with them. If this boggles you, think of it like this: every galaxy is in a car that is moving away from the other. If we welded those cars together, then they would still be moving, but moving together. Similarly, everything in our galaxy moves with the other, so this is not something you would see in the Milky Way.
The second thing to note is that these galaxies are not moving on their own accord, because according to the Hubble Constant at some point things really far away will appear to be moving away from us faster than the speed of light! However, this does not break physics, because the movement is caused by the expansion of space. Think of it like relaxing on top of a giant sheet of putty. If you pull it, you are not causing the motion, but rather the putty is. Similarly, the galaxies are not causing this motion but is a result of being carried away by the space under them. Since space is not matter, it does not violate any rules travelling faster than the speed of light or at any speed in general.
The second thing that is extremely important to point out is that the expansion of space does not create more matter, but rather just creates more space. This space is simply nothingness, so creating more nothing violates no conservation laws, including the conservation of energy or matter.
The most important thing to take away from this is that the universe is vast and continues to grow. As we try to learn more about space and space travel things are getting further away from us, and as the years go by feasible intergalactic travel becomes much more of an issue if we’re traveling by conventional distances. If humans truly want to explore the galaxy, we need to find a way to travel vast distances in short amounts of time. Maybe the answer lies in unlocking extra dimensions or other means, but the important thing to end with is that you, yourself, can ponder this and study this and one day profoundly change how we view things. Hubble was a simple man from a simple town and ended up profoundly changing the way we view space. Today there are so many astronomers that are tweaking Hubble’s predictions concerning the expansion of space. Even more, Hubble has inspired many with his work, including me. Whether or not astronomy is your inspiration, do not hold back. Take days to think and write and ponder, because only then will you be inspired to do something that you love and something the world will find amazing. Keep looking up.
As my last blog post for this class, I want to discuss one thing that has bugged me since we brought it up in lecture, and that is the Pioneer Plaque. For those of you who don’t know, the Pioneer Plaque is a plaque that was attached to the outside of the spacecraft Pioneer 10, featuring the depictions of a man and a woman, and information which, if decoded correctly, shows exactly what we look like, how big we are, and where to find us. Which brings me to my main concern – is that really a good idea?
I want to find evidence of life in the universe as much as the next person, but what if the life we find out there isn’t exactly friendly? We’ve basically given them a jump start on what they need to know to conquer us.
With everything we’ve learned this past semester there comes the glaring evidence that life is in fact somewhere out there, but we also seem to attribute a sense of ‘excellence’ to this yet undiscovered life – that is to say that we assume that the life out there will be better than us, more advanced. The thing is, however, that for all our advancement we also have serious flaws – we wage war and hurt others of our species for territory, resources, and due to ideological differences. How do we know any life out there won’t be the same? How do we know that by telling them exactly where we are, they won’t come and wage war on us to take our territory, resources, or because we simply don’t fit their idea of what life should be like?
Just like everything in life, the universe will eventually meet its demise. And while this event is not expected to happen for some time (estimates range from 2.8 to 22 billion years from now), scientists are wasting no time in theorizing about the end of everything. When scientists first started researching the beginning of the universe, they commonly thought that the universe was static and constant. However, newer data shows that the universe is actually expanding, and at increasingly faster speeds. By studying the expanding universe and the theory of relativity, scientists now have three popular scenarios for how the 14 billion year old universe will meet its end.
One theory is called “The Big Rip.” In this scenario, the universe’s increasing expansion would eventually overpower its gravity and would simply be ripped apart. Another theory is called “The Big Crunch.” Here, the opposite of “The Big Rip” happens. Instead of the universe’s expansion accelerating, it would instead reach a limit and begin decreasing. Then, gravity would overpower the universe, causing it to eventually collapse in on itself. Simply, this theory says the Big Bang would happen in reverse, causing the universe to revert back into a singularity. The final theory recognized by scientists is dubbed “The Big Freeze.” Based on the current knowledge of our universe and physics, this theory is believed to be the most likely. Also called heat death, this theory states that eventually entropy, a measurement of the shift of the idea that the universe will move from order to disorder, will reach a maximum. Once entropy reaches this maximum, heat will distributed evenly across the universe, and there will not be any usable energy, or heat, left. Thus, mechanical motion would cease to exist. Time becomes an endless void, and nothing new can be created or destroyed.
To call back to the late Carl Sagan, the study of astronomy is a humbling experience. The vast scale of the Universe is beyond true understanding relative to the human experience. Yet it is through the study of this incomprehensible immensity that one develops a regard for the significance an ever growing cosmic perspective affords humanity as a whole. To further our understanding of Earth’s seasons and tides, the icy moons of the jovian worlds, and the predominant solar system formation theory is valuable in its technical application as well as the underlying acknowledgement that our solar system, our planet, and our perceived unique individuality are interconnected. Understanding the Universe brings with it an implicit understanding of the self.
For a majority of human history, we were limited to the plots of land on which we stood. Earth, even in glory, is a fixed resource. With a fixed resource, the benefits of one will ultimately result in another’s detriment. Beyond the excitement I feel from the innate learning of astronomy, I see a valuable resource of its own with the humanity’s continued advancement toward space exploration. As we progress towards becoming an interplanetary species, the pie of resources expands. As a single planet civilization, humanity wages war against itself to claim victory over a moderately larger slice of the pie. Pie expansion will directly result from humanity’s expansion beyond Earth as our capability as a species develops and shared interests are emphasized. Where most advocate humanity becoming an interplanetary species as a necessity for the survival of our species, the deep study of astronomy reveals that not only is this true, but interplanetary capabilities are fundamental to human prosperity and happiness. My excitement about astronomy therefore stems from two sources: first, the very nature of learning about our place in the Universe has been a primary cause of infatuation since humans first gazed up at the stars, and continues to elicit this sense of wonder today. Second, astronomy will continue to benefit humanity as a species through the perspective it affords us. The further astronomy progresses, the further humanity progresses, and as a direct result, the less one’s benefit will adversely affect others.
WFIRST, which stands for Wide Field InfraRed Survey Telescope, is NASA’s observatory that is designed to research the area of dark energy, exoplanets, as well as infrared astrophysics for six years.
WFIRST’s primary mirror is 2.4 meters, which is 7.9 feet, in diameter. This size is the same as the size of Hubble Space Telescope’s primary mirror. These two telescopes also have the same structure. WFIRST has two instruments, the Wide Field Instrument, and the Coronagraph Instrument. The Wide Field Instrument has a field of view that is 100 times greater than the Hubble infrared instrument, and it is able to capture more of the sky by using less of the observing time.
The Wide Field Instrument, which is the primary instrument, will measure light from a billion galaxies over the course of the mission lifetime. It will also perform a microlensing survey of the inner Milky Way to find approximately 2,600 exoplanets. On the other hand, the Coronagraph Instrument will perform high contrast imaging and spectroscopy of dozens of individual nearby exoplanets.
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Recently in class, we learned about extremophiles – creatures that can survive in extreme situations. My personal favorite extremophile is the water bear (whose official name is the tardigrade) because they’re the hardiest extremophile (in my personal opinion). “Tardigrades have the ability to withstand complete dehydration. Once desiccated, they have been frozen in blocks of ice, exposed to radiation, and sent into the vacuum of space, and yet they still usually spring back to life when water becomes available again” (Seeker.com) – how awesome is that?
I honestly think that if we ever discover life on an alien planet, the first type of life will be like the water bears – creatures that can pretty much survive anything do after all make the most logical sense. Then again, I think water bears – and extremophiles – in general, provide specific evidence that what we think of as being the ‘qualifications for life’ aren’t the necessary qualifications for all types of life. Extremophiles, as creatures who by definition are, “organisms that have been discovered on earth that survive in environments that were once thought not to be able to sustain life” (Las Cumbres), it becomes apparent that as we look to the universe, we must expand on our version of just what ‘life’ is.
Just because it may not look, act, or live like us, doesn’t mean it isn’t living.
Scientists and knowledge seekers alike have always wondered about the source, composition, and evolution of both life on Earth and beyond. This field of study is known today as astrobiology, and scientists in this field are currently trying to answer the following question: could life exist beyond Earth?
In solving this puzzle, the European Space Agency sent a group of extremophiles known as tardigrades into space on their spacecraft FOTON-M3 in September of 2007. Extremophiles are a classification of organism that can survive in usually extreme environments. The tardigrades being studied here are also called “water bears,” and these organisms can withstand dehydration, cold, heat, and even radiation. Their ability to resist radiation is the reason scientists became interested in these microorganisms. While in space, the water bears were nakedly exposed to the space vacuum and cosmic rays, as well as the deadly levels of UV radiation found in open space. Almost all of the specimens survived the vacuum and cosmic rays, and some even survived the UV radiation as well. These conditions usually would kill any living being within seconds.
Scientists are still puzzled as to exactly how the water bears can withstand such extreme environments. In regards to being dehydrated, the water bears simply enter a dormant state in the absence of water and will become active again once water is present. While, this ability does not seem to have direct answers as to their abilities to survive in space, it could be a clue. Other scientists also speculate that water bears must have an ability that can repair their damaged bodies. They explain that those tardigrades that did survive the UV radiation still experienced some level of DNA damage but that the microorganism was able to heal itself.
In studying the survival skills of water bearers, astrobiologists hope to gain a better understanding of the types of life that could exist on planets with less than desirable environments. The water bears’ ability to possibility regenerate damaged DNA is of particular interests to cancer researchers, who hope that understanding the microorganisms’ abilities could lead to advances in cancer radiation treatments.