Monday, March 31, 2014

Becoming a NASA Astronaut

Do you want to be a NASA Astronaut? I know I do. Have you wondered if you have what it takes? Wonder no longer! Through this essay I’m going to solve all of these mysteries.

So what is an astronaut? The term astronaut comes from the words ‘space’ and ‘sailor’. NASA calls humans that travel on space mission’s astronauts. In a way they can be thought of as "space sailors". The astronauts have different roles in the spacecraft. The categories the astronauts are organized into are commander, pilot, mission specialist, or payload specialist. In order to become an astronaut you must also be a US citizen.

Commander astronauts are important in the Space Shuttle and International Space Stations. During the flight, the commander is responsible for the vehicle, crew, mission success, and safety of flight. In order to become a Commander you must have certain requisites. You must have a bachelor's degree from an accredited institution in engineering, biological science, physical science, or mathematics. In order to be accepted you must have a very impressive resume, because becoming a commander is the most competitive of all the positions in the space craft. In addition you must have experience in a jet aircraft.

In addition to having mental capabilities, you must be able to pass a NASA space physical! This test is designed to be similar to a military physical. You must be around 5' 3" at the least, with proper vision and good blood pressure.

Personally I was expecting a more grueling process physically but it shows it is more important to have mental capacity.

Secondly, the mission specialist astronauts work with the commander and need to manage the systems, crew activity planning, consumables usage, and experiment/payload operations. They perform the tasks that the commanders tell them to. They are also responsible for bigger picture mission aims as well. For example they take care of the activities they need to perform on the shuttle, the food, other consumables, and conduct mission objectives. In order to prepare, they must learn of all aspects of operational characteristics, mission requirements and objectives. Mission specialists will perform extravehicular activities, and typically conduct any experiments or remedial tasks.

In order to be capable for a position as a mission specialist you must have the following (from the NASA website):

1. Bachelor's degree from an accredited institution in engineering, biological science, physical science, or mathematics. Degree must be followed by at least three years of related, progressively responsible, professional experience. An advanced degree is desirable and may be substituted for part or all of the experience requirement (master's degree = 1 year of experience, doctoral degree = 3 years of experience). Quality of academic preparation is important.

2. Ability to pass a NASA space physical, which is similar to a military or civilian flight physical and includes the following specific standards:

Distance visual acuity: 20/200 or better uncorrected, correctable to 20/20, each eye.

Blood pressure: 140/90 measured in a sitting position.

3. Height between 58.5 and 76 inches.

The final astronaut position is the payload specialist. A payload specialist is someone who is not a classically trained astronaut but has specialized onboard duties. To draw from an example from class, in the movie Armageddon, the employees of the drilling company would be considered payload specialists. They are put into the crew if activities that involve unique requirements are involved, however typically payload specialists are not frequently included and first priority always goes to mission specialist with the skill set they are looking for. Because payload specialists are not part of the typical Astronaut Program, there are far less formal requirements for them. However, they still must pass certain physical requirements.

Becoming an astronaut is something that is extremely selective; however, if you are committed to your studies and keep your eyes on the prize, you can do it! Finally, with regards to my astronaut dream, it is still alive!
Connor Moore

Friday, March 28, 2014

Kardashev Scale & Conquering the Universe

As humans, we often lose sight of how insignificant we are in the grand scope of things. Out of the millions upon millions of galaxies, we only live in one, and inside of that galaxy, we inhabit only one solar system, and even further, one planet. We merely represent a single point on the infinite space-time continuum. But that is about to change, says the MarsOne Space Exploration Company. Their goal is to successfully land humans on Mars so that we can begin to inhabit it. Dubbed “the next giant leap for mankind”, the first mission will be launched in 2018. While this is still incredibly insignificant in the big picture, this would be a very monumental step in populating and inhabiting the universe, if that is the ultimate goal going forward.

However monumental of a step this turns out to be, we are still a type 0 civilization according to the Kardeshev Scale, which is “a method of measuring a civilization’s level of technological advancement, based on the amount of energy a civilization is able to utilize”. The more energy a civilization can utilize from various sources, thus produces a proportionally higher level of civilization, going from level 0 to 3.

In further detail, a type one civilization ranking is given to one that is able to harness all of the energy from the nearest neighboring star, and in turn meeting all of their society’s energy needs. To put this in perspective, if we as humans wanted to attain this energy standard, we would need to boost our energy production by 100,000 times. In addition to having this much energy, we would have the power to control all natural forces, including volcanoes, earthquakes, and the weather.

A type two civilization would not only have the capabilities of a type one civilization under the assumption that they could harness all of the power from the nearest star, but they would also be able to now control the star. If humans lived long enough to reach this status, we would have reached a level of invincibility. Nothing known to science could wipe out a type two civilization. A moon-sized object hurtling towards the Earth would not even pose a threat. Humans of this age would have more than enough resources to obliterate this threatening object. Humans could vaporize it, move the Earth out of the way, or move a planet such as Jupiter in front of us to block it from hitting us.

Lastly, a type three civilization would encompass a race that had the ability to travel across the galaxy with an ultimate knowledge of everything that has to do with energy. The species that have attained this rank would go on to populate and colonize star after star.

Kardashev did not believe that it was practically possible to become any type of civilization after a rank of three. Yet for theoretical reasons, other scientists laid the groundwork for a type four and type five civilization. A type four civilization is one that could harness the energy of the entire universe. And a type five civilization is that of one where the people had god-like powers, able to manipulate and control the universe however they please.

As a type 0 civilization, it only underscores how immature and insignificant of a society we are. However, companies looking to pursue similar endeavors like the MarsOne initiative have us on the right track for advancing us as a society.
Tyler Wellener

Computer Simulated Reality

What if reality was just a simulation? Humans have always tried to attribute different reasons as to why and how our universe exists. In the beginning, we had the concept of God, a supernatural being who created everything. Although the majority of the world still believes this, the Big Bang Theory has risen as well. But where did this big bang come from? Could it be that the bang was simply the start of a long computer simulation that a highly developed race created?

Let us look at our own progress as humans. 200 years ago, we did not have industry. 20 years ago, we did not have cell phones. The rate at which computers are improving, in 50 years we could have computers a million times as powerful as the ones we have today. Clearly technology is progressing, and it seems exponentially. In Stephen Wolfram’s A New Kind of Science, he shows that every field of knowledge and every aspect of life can be broken down computationally. If life can eventually be broken down to 1’s and 0’s, at some point, is it not conceivable that with the processing power we will eventually achieve, we could create a program of a person who thinks and has feelings just like we do? And if that is possible, could we not create more people like that, and then environments for them to interact with? In fact, we are already simulating universes: The Odyssey Supercomputer at Harvard University can recreate 14 billion years of galaxies forming and changing.

Now, what if we do somehow get to the point we can create these simulations of people who believe they are real? That would put our own existence in question. If we can do that, then it is very possible that we are also simply a computer simulation created by an advanced race. But that group of beings could also being living in a simulation, which leads to the question of who created the first simulation. That cannot be proven as of now, which leads us back to square one. Maybe it is a god.

Another interesting question that arises is if our creators are humans like us. Maybe we are just like our creators biologically. Or perhaps our creators are some sort of alien from a far away galaxy. Let us assume that our creators’ race is the XYZ race. They must have created their own race in their computer simulation, but regardless of that, to create us, they must have met us in their own lifetimes. Furthermore, if they created their own race, the XYZ race exists somewhere in our simulated universe. With the assumption that our creators are not humans or simulated humans, we will likely meet other forms of life before we create simulated universes ourselves.

The idea of living in a simulated universe could be very troubling for many. If our universe is not truly reality, then what is the point of life? However, regardless of how our universe came to be and why, our sense of reality is relative to us. We live our lives in this universe without knowing anything better. In this sense, ignorance is bliss. Our universe is real relative to our experiences, so there is no use in frustration due to a belief in a simulated reality.
Favian Rahman

Extraterrestrial Exterminators

One great aspect of the human race is that we are, in general, naturally curious beings. This curiosity is apparent in discussions of space not only today, but also seemingly as far back into our history as written records allow us to look. We have always been intrigued by the seemingly endless possibilities that lie in space, especially the possibility of extraterrestrial life. As we develop technology that makes space travel increasingly possible, the purely philosophical debates of extraterrestrial existence have taken on aspects of possibility and practicality. So the question becomes, if we are capable of seeking out extraterrestrial life, should we?

This is a very tough question to answer, as there are innumerable arguments both for and against this type of space exploration. I recognize that the traditional oppositions to space exploration (cost and danger among others) are valid and require answering to. However, my main concern with seeking out extraterrestrial life right now is that I simply don’t believe that the human race is ready for contact with another species. I hold this view based purely on historical events as well as the current state of world affairs. As a species, we seem to be physically incapable of getting along with each other. This fact is apparent in our endless history of war, genocide, and simple lack of harmony in our interpersonal as well as international relationships. People like to believe that humans nowadays are more advanced and mature than our ancestors. I disagree. How is a species that only 70 years ago attempted to completely exterminate an “inferior” community of people in any way mature? The answer is that we are not. Because of this lack of maturity I don’t believe that we are ready to be in contact with extraterrestrial beings. If we cannot even get along amongst ourselves, there is no way that we can be expected to get along with a completely alien species. Who is to say that, if this extraterrestrial species is considered to be “inferior” to us, we will not become the exterminators in the interest of our own personal benefit?

Despite my extreme pessimism about the current state of the human race, I do remain highly optimistic about the future. I strongly believe that the day will come when our race will become enlightened and our violent ways will all but come to an end. When that day comes, we will be ready for extraterrestrial contact, and I hope that that contact will be achieved. However, I don’t see that day of enlightenment coming any time soon. Despite my earlier rant on our current immaturity, I do believe that we should be engaging in space exploration. Even though we are only just now scratching the surface of space travel, what we do now will set the fundamental foundations for all future space travel. By setting these foundations, our species will hopefully have the technology and capability of contacting extraterrestrials when that day of enlightenment comes. We need to act as the brave trailblazers that set out into an unknown frontier now so that future generations will be able to more thoroughly explore space. My only hope is that by the time that our technology is advanced enough to come into contact with extraterrestrials, that we are mature enough as a species to handle that contact.
Tristan Lockwood

The Only Way to Save the Populace: Expansion into Space

Although the Earth has been around for billions of years, it’s obvious that the Earth won’t be around forever. I will discuss two of the major reasons that the Earth, and logically following, all of its life forms could meet their doom in the near future. I will use these reasons to argue that human expansion into other planetary realms is a necessity to ensure the survival of humankind.

The biggest issue in recent years that leads to talk about a possible future inhabitability of the globe is a term that’s been thrown out a lot: global warming. Before talking about how humankind is involved, it is important to note that there also exists a natural climate change. It has gone from freezing temperatures with periods where the oceans were completely iced over, to blisteringly hot temperatures. This natural variability takes quite a while to go from one extreme to the other. It is also predictable to some extent (due to Milankovitch cycles, which use the tilt, precession, and eccentricity of the Earth to detect climate change patterns), and so should not provide much of a problem for humankind.
A polar bear on top of melting ice,
an effect of global warming.
Additionally, natural climate change only accounts for a slight variation in temperature over the years­. This indicates that although global warming consists of both natural and anthropogenic parts, the anthropogenic part may be the one causing the majority of the damage. Human invention and technology (specifically those that use or rely on coal, oil, and other “dirty” energy sources) warm the Earth by releasing greenhouse gases that bring in increasing quantities of harmful UV radiation. As long as people continue to rely on modern day technology, such as petroleum-based transportation and electricity consuming appliances, the anthropogenic portion of global warming will continue to persist. This one problem alone can lead to numerous ways in which humans could meet their end, including but not limited to: floods caused by rising sea levels due to melted polar ice caps, normally occurring weather-related disasters, and stresses to other forms of life, thereby destroying the tightly packed network of the global food chain.

Another major issue that could lead to human extinction is a possible collision by a meteorite. In
An artist rendition of meteorite impact
destroying the dinosaurs.
the past, dinosaurs were thought to have been destroyed by a giant asteroid. If even the giant fearsome dinosaurs were killed by an asteroid, how would frail, puny humans (in comparison to the giant dinosaurs) fare? It doesn’t take an expert to realize that an asteroid of decent size could cause major damage to human life. Although large meteorite collisions are rare, just one could wipe out all of humankind. To give an idea of how rare large meteor collisions are, a 1 km meteorite that could cause a nominal global effect (about 1 million fatalities) is expected to occur once every million years, and a 10 km extinction class event is only expected to occur every 100 million years. Despite the low probability of events, if a meteorite did threaten to hit, humankind would either need a way to repel it or an escape route to ensure survival. Ways to deal with incoming meteors are currently in the works, but as of yet, there is not confirmed deterrent method. Meteors are just one facet of all the cosmic threats humankind faces, many of which could happen in the near future.

Because of these impending threats to planet Earth, it is essential that the human race move outwards, and find new places to live across the universe. There are many risks associated with space travel, such as poisonous radiation, and we should start finding ways to prevent or at least reduce these problems today. That way, if the time ever comes that we need to leave planet Earth to ensure our survival, we will be ready. Lastly, you may note that I did not include the risks of artificial intelligence and manmade nuclear weaponry that could obliterate the population. This is due to the fact that these threats will exist no matter where humans live, and so there is not much of a way to account for these (other than separating the human race into multiple planetary environments). We should rather spend our time preparing for threats that matter on our current planet, where all of humankind currently resides.
Arjun Manimaran

Friday, March 21, 2014

The Fate of Our Universe

Ever since the discovery in 1929 that our Universe is expanding, three main fates of the Universe have been hypothesized over time: “The Big Crunch,” “The Big Freeze,” and “The Big Rip.” The Big Crunch presents a horrific representation of how the world will end, with the Universe collapsing on itself to create enough heat to cause oceans to boil, rock to melt, and eventually all people will die in the intense heat. However, this fate could be part of a cyclic Universe, giving the possibility of regeneration of life in the future. In contrast to the idea of the Big Crunch being the end of life as we know it, the Big Rip presents a fate where the Universe expands so fast that galaxies, stars, solar systems, planets, all the way down to people and atoms will eventually be torn apart. In between these two fates is the Big Freeze, which presents a “cooler” way for things to end. The Big Freeze predicts an ever expanding Universe, in which the size of the Universe continually increases, and where motion eventually ceases, causing the Universe to lose heat and freeze.

This loss of heat also encourages the other name for the Big Freeze, “Heat Death.” While this name at first seems ironic, it comes from the idea that in an isolated system, entropy, the measure of a system’s disorder, will continuously increase over a span of 1014 (hundred trillion years) until it slowly continues to reach a maximum value, where heat is evenly distributed in the system. The even distribution does not allow for usable energy to exist, such as heat, since there must be a temperature gradient for mechanical work to occur; therefore, no more motion will be possible, causing everything to eventually become too cold to sustain life and causing star formation to cease. Once the freeze happens, atoms and particles will begin to decay into photons and after 10116 years, most particles will have disintegrated. Finally, all matter would evaporate leaving only black holes in the Universe, which would also eventually break down. After 10200 years, the Universe would be empty. This progression of events is explained more in depth here. Another hypothesized procession of events is diagrammed here, where the “Heat Death” is said to happen after 101000 years.

The fate of the Universe depends on its density and composition, which affect the shape. The shape of the Universe is determined by the density of the Universe; if the density is less than the critical density, then the Universe would be saddle shaped, if the density is equal to the critical density, then the Universe would be flat, and if the density is greater than the critical density, the Universe would be spherical. Depictions of these different shapes are shown here. If the density of the Universe is less than or equal to the critical density, the value for which the Universe has a flat shape, then the Big Freeze will be the fate of the Universe. However, if the density of the Universe is greater than the critical density, even though the Big Crunch is also likely to happen, it is still possible for the Big Freeze to happen if there is enough “dark energy” in the Universe to speed up the expansion. According to the measurements made by the Wilkinson Microwave Anisotropy Probe, or WMAP, the density of the Universe is less than the critical density, but close enough to the critical density that it shows the Universe to be flat. These signs point to an expanding Universe, so there may be a Big Freeze in our future.
Emily Helfer

Citizen Science Tackles Big Data Astronomy

CosmoQuest, an organization dedicated to exciting and engaging the public in astronomy research along with mapping different aspects of the universe, recently unveiled Moon Mappers; the project is designed to crowdsource crater counting on the moon by enlisting interested amateurs. Simply put, crowdsourcing enables people or companies to obtain information by outsourcing their work to others, usually via the Internet. By employing the power of thousands of Internet users to count and sort craters, CosmoQuest hopes to expedite and refine their mapping efforts. CosmoQuest’s endeavor is in no way the first attempt to use novices for astronomical observation; in recent years, astronomers have progressively turned to the masses for aid in classifying steadily increasing amounts of new data.

In the past 40 years, the field of astronomy has blossomed from the upsurge of vast amounts of data collected from revolutionarily advanced telescopes and light detectors. The Hubble Space Telescope, the Sloan Digital Sky Survey, and other methods of observing and mapping the Universe offer unprecedented amounts of new and unsorted material. Currently, most automated classification algorithms lack the precision necessary to accurately categorize galaxies; however, the immense amount of data makes any individual effort at classification essentially futile. Crowdsourcing has provided an apt solution. In 2006, the University of California Berkeley, in conjunction with NASA, first began posting pictures from an interstellar dust collector on the web as a part of the Stardust@Home project, enticing curious Internet users to search for particles. With the expansion of both the Internet and astronomy data, crowdsourcing universe observation has become an increasingly appealing option for both astronomers and amateurs.

Today, astronomy related citizen science projects have grown to include organizations such as Galaxy Zoo, which allows anyone with an Internet connection to classify galaxies using data from the SDSS. Upon entering the site, users are asked a series of identifying questions regarding particular galaxies and are instructed to categorize by shape, spirals, and distinguishing odd features. From this data, astronomers can often ascertain information about surrounding atmosphere, age, and more. Co-founder of Galaxy Zoo Kevin Schawinski notes "we had succeeded in creating the world's most powerful pattern-recognizing super-computer, and it existed in the linked intelligence of all the people who had logged on to our website: and this global brain was processing this stuff incredibly fast and incredibly accurately.” The site, which has now expanded to 800,000 unique users, has already provided the bases for 42 formal scientific papers. Amateurs can still impact the field of astronomy through crowdsourcing; their efforts are powered by interest and curiosity instead of prizes or financial incentives.

However, detractors have voiced concerns regarding the scientific accuracy of such novice evaluations. Crowdsourcing research projects often offer little preparatory instruction and require no formal astronomy background. The University of Colorado Boulder recently tested the scientific rigidity of such projects; their study presented both novices and astrophysicists with lunar craters to count, similar to CosmoQuest’s Moon Mapping project. Surprisingly, the amateurs produced the same quality results as professionals. Crowdsourcing projects, including Galaxy Zoo, frequently ensure that their data collection is accurate; Chris Lintott, a Zooniverse leader, states that since the same galaxy is classified repeatedly by many users, accidental mistakes are generally avoided. Similarly, “the system insists that every classification is independent, and as…several people look at each classification finding any deliberate attack would be easy – in any case, we’ve never seen any evidence of such a thing.” Nevertheless, Zooniverse and other crowdsourcing projects are still in the process of filtering out unintentional error and biases; humans tend to classify anticlockwise galaxies easier, leading to sampling bias. In order to combat systematic error, in which users frequently misclassify the same systems, Zooniverse researchers methodically flip galaxy pictures and attempt other methods of reducing partiality.

With new data collection projects currently in development, including the Euclid spacecraft and the Large Synoptic Survey Telescope, it is unlikely that the necessity of citizen scientists will soon cease. While only computer classification algorithms will offer a truly realistic resolution to the big data predicament in astronomy, crowdsourcing provides a temporary solution that aids the field and engages and inspires amateurs. In a field where the data increase by factors of two annually, manpower through the masses is dramatically altering data classification for the better.
Laura Gunsalus

The Golden Age of Astronomy

When we look to the past it is clear that there have been golden ages associated with different cultures and technologies. For instance in the 1920’s to 1940’s there was the golden age of radio, from 1960 to 1975 the golden age of general relativity, and so forth. However, what most people may not realize is that we are actually in the beginning of the golden age of Astronomy and the related Physics pertaining to our Universe. The amount of new information pertaining to our Universe, collected by telescopes such as the Sloan Digital Sky Survey, has been so massive that astrophysicists such as Ray Norris from CSIRO Australia Telescope National Facility has stated that we are in the beginning of a golden age of astronomy.

So why does Ray Norris consider this to be a golden age? Well, when we look at all the Universe, it is clear that we have long been observing only that 4% of the Universe composed of normal matter; the other 96%, composed of dark matter and dark energy, has yet to be explained through physics. However, with the recent discovery of the Higgs Boson at the Large Hadron Collider, these unknown entities can be further studied. What this means is that there is potential for many new discoveries and that the fields related to space are ripe with opportunity. From this it may seem that the Higgs Boson discovery as well as the massive amounts of new information gathered from sky surveys can be considered the start of this age. But actually when you also consider the technology surrounding the field of astronomy, as well as the amount of interest in the field it is hard to put an exact date to the start of this golden age.

Specifically, one way astronomy has improved technologically is one of the most basic ways of observing space, telescopes. In the past, telescopes were comprised of single, static mirrors and thus there were limits on their size and resolving power. However, with the improvements in engineering, we are able to create optical telescopes that are 30 times larger than we were able to create 25 to 30 years ago. Alberti Conti states that with our abilities now, when we retrofit the large mirrors with detectors, they are not 30 times better, but rather 3000 times better. In the case of these telescopes, the detectors are silicon chips divided into rows and columns, making “pixels.” Then when a photon hits a pixel, an electron gets knocked loose and stays in the “pixel.” The number of electrons basically equals the amount of light hitting the pixel. Ultimately, these chips make recording the light that passes through much more efficient. This combination of new engineering techniques comprising the use of multiple mirrors as well as the use of detectors is essential to the spark of the golden age because of how much more light gathering power modern day telescopes possess.

In addition to optical telescopes, radio telescopes such as the Australian SK Pathfinder has 200 receivers compared to other telescopes which use fewer receivers such as the Arecibo Observatory which makes the volume of data increase by 100 fold, which in turn leads to the potential of discovery to increase by 100 fold. This massive increase in detection efficiency goes hand in hand with Moore’s Law, a law stating that our ability to process data doubles every two years or so. Along with all this data, this has caused astronomical advances to become more reliant on data mining and statistical methodologies.

So with new massive databases of information, astronomical discovery has become much more feasible for a larger group of people. In the past, if astronomers wanted to study the sky, they would have to reserve time at a large telescope and hope for optimal conditions. However now, with free widespread data, it has become much easier for people to analyze data. In addition to the free data on the internet, organizations such as Galaxy Zoo have been created. These organizations ability in crowdsourcing people with an interest in astronomy and has helped the classification of galaxies at a rate of 70,000 per hour compared to an average single person’s classification rate of 50,000 galaxies per year. Essentially, with the massive amount of free data as well as the increase in publicity and exposure of astronomical data, the field has received many more contributors than compared to the past which has helped with the analysis of the massive amounts of new data.

With the technologies surrounding data gathering getting significantly better, it is easy to see why astronomy is currently in a golden age. With so much new data available for so many more people, it is evident that astronomy has become a field for more than just the lucky who were able to receive new data, but for any person with an interest in the field. In the future, I believe that astronomy will continue its golden age through continued improvements in technology and data gathering, but also with discoveries and advancements in related fields of physics as well. It is hard to judge, but right now we are at the dawn of a massive age of discovery concerning more than just the Universe we can see.
Justin Kim

Europa Recreated

Europa, discovered in 1610 by Galileo Galilei, is the sixth-largest moon in the Solar System. It has an extremely thin atmosphere primarily composed of oxygen and a surface of smooth water ice. The geological structures observed during a space mission by the two Voyager probes suggest there is an upwelling of fluids coming from the inside, as well a composition of volatile compounds like carbon dioxide, sulfur dioxide, and hydrogen peroxide. Scientists believe that beneath Europa’s icy crust, a large ocean made up of water, salts, and gases could exist. If a reservoir of liquid water exists inside Europa, scientists believe there could be life.

Victoria Munoz Iglesias proposed, “Just like Earth’s magma emerges to the surface, a similar phenomenon could occur in Europa. Although, in this case it would be a watery cryomagma that would evolve and emerge outwards from the interior of the icy moon.” To test this hypothesis, Munoz's team simulated an experiment in the laboratory, replicating the extreme conditions in the moon’s crust. Scientists examined pressures up to 300 times that of the Earth's atmosphere at temperatures near zero degrees Celsius.

The scientists waited to see what would happen to an aqueous solution of carbon dioxide and magnesium sulfate in these extreme conditions when it emerged and cooled on the surface. Depending on the fluid’s evolution, three types of minerals were formed inside of the crust including water ice, clathrates (chemical substances consisting of lattices that trap or contain molecules) of carbon dioxide and very hydrated magnesium sulfates. Each of these processes act to change the volume of the upwelling cryomagma and thus to deform Europa's crust. If the quantity of clathrates is less than the quantity of hydrated salts when the process is over, the volume increases making visible topographical features in the crust. On the other hand, if there is a greater quantity of clathrates than the quantity of hydrated salts, or if the process is destroyed, the volume decreases causing depressions in the crust. This is consistent with the seemingly chaotic nature of Europa's terrain.

However, Jupiter and its other moons affect the appearance of the surface in a way not replicated in the lab. Among the theories of why the Europa had a reddish color, the two most viable are that the color is a result of strong irradiation from charged particles in Jupiter's magnetosphere and that the color results from the bombardment of volcanic sulfurous compounds from other moons such as Io.

The Munoz experiment supports the hypothesis that a saline aqueous medium, capable of hosting life, can replicate observed characteristics of Europa's surface, thus reinforcing the need for a space mission to Europa. President Barack Obama has presented NASA with fifteen million dollars to search for signs of life on Europa for the next ten years. In addition, the European Space Agency has also planned to launch the Jupiter Icy Moons Explorer Mission in 2022. When this spacecraft arrives at Jupiter’s moons, it will fly over Europa two times to measure the thickness of its crust and explore its habitability. A mission to Europa is crucial in expanding our knowledge about the moon's crust and making new discoveries to see if it is capable of fostering life.
Clara Lee

Halley's Comet

An image of Halley's Comet
captured during the 1986 sighting.
Since before the beginning of recorded history, humans have been awed by the sight of a bright astronomical object streaking across the sky with a long tail extending from it, Halley’s Comet. These sightings occurred roughly every 75 years, but not until the Enlightenment was it realized that these sightings occurred on such a cycle and that the object seen was the same object each time. Written accounts of sightings of the comet can be traced back to 239 B.C. when Chinese astronomers recorded seeing it pass through the sky. It was noted in other ancient records and throughout the Middle Ages. People often saw the comet’s appearance as an omen of coming disaster or change. For example, Halley’s comet appeared around the time of William the Conquerer’s invasion of England in 1066.

The Bayeux Tapestry depicts William
the Conquerer's invasion of England
in 1066. Halley's Comet can be seen
in the top center of the photo.
During the Renaissance Copernicus published the idea that the solar system revolved around the sun, not the earth. When English Astronomer, Edmond Halley saw the comet himself in 1682, he used the idea that astronomical objects orbit the Sun as well as his friend, Isaac Newton’s newly published laws of gravity to study the comet’s behavior. He used records of comet sightings across several centuries and the fact that the orbits were very similar to conclude that these sightings were all the same “periodic” comet. Up until this point, no one realized that these sightings were linked. 

Halley’s Comet is a short-period comet, meaning it has an orbital period less than 200 years. Halley’s Comet is the only of these short period comets that can be seen easily from Earth with the naked eye, making it the most well known. It is suggested that Halley and other short-period comets were once long-period comets (more common types of comets that have orbital periods of thousands of years) that had their orbits perturbed by the gravity of the giant planets, which sent them flying in toward the inner planets. If this is the case then Halley’s comet probably originated from the Oort Cloud, a field of icy rocks that extends up to a light year from the sun. It is estimated that Halley has been in its current orbit for tens or even hundreds of thousands of years.

When Halley’s Comet came near Earth in 1986, humans finally had the space technology to observe it up close. The European Space Agency and NASA as well as Japan sent spacecraft to capture images of it. These missions allowed scientists the opportunity to determine that Halley contains compounds like carbon monoxide and carbon dioxide which, when the comet approaches the sun, heat to give the comet an atmosphere, or coma. The solar wind blows this coma away from the comet, creating the characteristic tail. The debris left behind in Halley’s path is responsible for the annual Orionid meteor shower in October when the Earth passes through these remnants. Halley’s Comet is predicted to return in 2061. Who knows what new things we will learn about it with the technology that will be available half a century from now?
Clare Isaacson