# The Magic of the Ocean and the Moon

Original artwork by the author

by Bree Gerold, AP Physics 1 Student

Perhaps it is the oh so exciting thought of spring break quickly approaching, or maybe it is my constant fascination with the ocean, but recently I have found myself in a daydream about the beach.  Ever since I was a little girl, I have always been fascinated by the rising and the falling of the ocean waves.  I remember that it always baffled me how the ocean could get bigger, then shrink back up again, like clockwork.  I didn’t understand it.  I didn’t understand gravity, I didn’t understand physics.  Perhaps there is a bit of magic to that; to the complete innocence of a child who is so easily mesmerized by something as simple as the ocean’s tides.  That’s what it was to me.  It was magic.

Now as a senior in high school, I have been through many physics classes and have managed to gain at least enough knowledge to understand how the moon and the ocean create the tides.  Ocean tides are created by combining the gravitational pull of the moon and the sun, combined with the rotation of the earth. The moon’s gravitational pull is stronger than the sun’s which makes it the most important factor in creating tides. The tides are really long-period waves that appear as the rise and fall of the sea as they reach the coastline. High tide is the crest of the long-period wave and low tide is the trough of the long-period wave. The earth rotates on its axis once every 24 hours and the moon rotates around the earth once every 28 days. The moon pulls upward on the ocean while the earth pulls down. This causes tidal movement. The tidal troughs are separated by about 12 hours. Because the moon rotates around the earth, it’s not in the same place at the same time every day.  So the high and low tide times change every day by about 50 minutes.

Even now, after understanding the physics of it all, it still seems like magic.  It is magical how the moon, that is so far away, can have such a compelling effect on the little girl I once was.

Works Cited

“Ten Cool Facts About Ocean Tides.” Oceans52. WordPress, 05 Apr. 2012. Web. 06 Mar. 2016.

# Earth, Physics and Imagination

by Leslie Medina, AP Physics 1 student

Painting by Leslie Medina

When I think of Mother Earth, I imagine hearing a pulse, and I visualize all the natural beauty that Earth contains. When I give such human-like qualities to Earth, I envision her breathing, even though I know this is not how things work. I think about all the possibilities and opportunities that Earth has given us. The ability to live, explore, and gain knowledge about our universe and the galaxies that endlessly fascinate us. When I depicted Earth breathing and exhaling, I was visualizing how Earth metaphorically takes in knowledge of its surroundings.

With this knowledge, there is an even greater desire to learn more about Earth, space, and life itself. Physics explores many things concerning these expansive topics and attempts to offer an explanation of all the extraordinary phenomena that surround us. On my painting, various equations and key details concerning gravity, orbits, and planets, appear as stars in the night sky. What I’ve come to realize is that these equations not only fill up the background space of my painting, but they also fill up the spaces in our curious minds with an abundance of knowledge.

Leslie Medina is an Honors/AP student at Creekview High School, and she is also an amazing artist.

Image

# What are Dark Matter and Black Holes?

by Briana Purves, 6th period CP Physics

Most people consider dark matter and black holes to be mysteries; however, with the help of scientists and technology, these mysteries can be understood! Dark matter is a nonluminous material that exists in space and can appear in many different forms. Black holes are a region of space with a gravitational field so intense that no matter or radiation can escape it. Black holes also have the ability to deflect light, but dark matter does not. Overall, there are many things that we can learn about both dark matter and black holes.

Nonluminous, dark matter is postulated to exist in space and can take any of several forms, including weakly interacting particles or even high energy randomly moving particles created soon after the Big Bang. Although it is not in the form of visible stars and planets, scientists have deduced the existence of dark matter because there is not enough visible matter in the universe to account for the gravitational effects present in the universe. Research supports that dark matter makes up a substantial percentage of the matter-energy composition of the universe, while the rest is dark energy and “ordinary” visible matter. Dark matter is not in the form of dark clouds filled with normal matter, but can be seen as matter made by baryons particles that are composed of protons, neutrons, and electrons.

Dark matter was originally known as the “missing mass” until Fritz Zwicky discovered that the mass of all the stars in the Coma Cluster of galaxies provided about one percent of the mass required to keep the galaxies from escaping the cluster’s gravitational pull. Missing mass remained a question until the 1970s when two American astronomers proved its existence through the idea that the mass of the galaxy within the orbit of stars must increase linearly with the distance of stars from the galaxy’s center. Also, dark matter is not capable of being composed of antimatter, because scientists would be able to see gamma rays that have been produced when antimatter annihilates with matter. Scientists are still unsure of the exact composition of dark matter, but the most common view is that dark matter is made up of exotic particles called axions, or weakly interacting massive particles.

Conversely, black holes are a region of space that has a gravitational field so intense that no matter or radiation can escape it. The gravity of a black hole is so strong because the matter has been squeezed into the tiny space, not allowing it to escape. People cannot see black holes, as they are invisible to the human eye, and can only be detected by advanced special telescopes. Black holes come in many different sizes and shapes, from the size of a large planet to as small as just one atom. Even the extremely small black holes contain massive amounts of matter inside.

One type of black hole that has been discovered is called a Stellar. Stellars can grow to be up to twenty times as big as the mass of the sun; however, there are black holes that can grow to be even bigger; these black holes are called Supermassives. Supermasssives can have masses up to one million times greater than the sun’s mass. Scientists have found that these Supermassive black holes are most commonly found in the Milky Way (also known as Sagittarius A) and have a mass equal to four-million suns and a few million earths.

Black holes are formed when the center of a star falls in on itself causing a supernova or when an exploding star blasts parts into space. Many black holes cannot be seen today because of the strong gravitational pull of light into the center of the hole. When a black hole and a star are near each other, high energy light is made that can only be seen by satellites and telescopes in space.

Einstein’s Law of General Relativity explains why black holes deflect light. Einstein’s law states that a ray of light arriving from one side of an object is bent inwards so that its apparent direction of origin, when viewed from the opposite side, is seen as a different angle. The observed gravitational effect between masses will result from their warping of space-time. Einstein’s Law of General Relativity predicts that every object’s gravitational field bends light rays which is called gravitational lensing. According to Wikipedia, “A gravitational lens is a distribution of matter between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer.” Einstein’s Law of General Relativity also supports that the gravitational fields of massive objects causes a distortion in space-time. Einstein’s Law of General Relativity proves just how black holes have the capability to deflect light, as they are able to bend light rays through its gravity.

People have the capability of learning infinite things about both dark matter and black holes. Such things can include how dark matter is known as a nonluminous material that is postulated to exist in space and that can take any of several forms, while, contrarily, black holes are known as a region of space that has a gravitational field so intense that no matter or radiation can escape. Black holes also have the capability to deflect light, which can be proven by Einstein’s Law of General Relativity and through gravitational lensing. If all of these things can be learned about dark matter and black holes through the writing of this one essay, imagine what can be learned throughout a lifetime.

Briana Purves is not only an excellent physics student, she is an outstanding softball player.

# Creekview AP Students Detect Exoplanet Far from Our Solar System

During the week before spring break, when most students have their sights set on sunny, sandy shores, the Creekview High School Advanced Placement Physics students were looking to the heavens. In collaboration with the Harvard-Smithsonian Institute of Cambridge, Massachusetts, these students remotely manipulated the MicroObservatory telescope, located at the Smithsonian’s Whipple Observatory near Tucson, Arizona, to collect images of distant stars and analyze the images for evidence of exoplanets, planets orbiting stars other than the Sun. After several days of studying the star HATP-36, the students were able to deduce that they had found an exoplanet orbiting this star thus joining the few humans who have detected a planet orbiting a star far beyond our own solar system.

The adventure began when Creekview’s AP Physics teacher Kim Geddes applied to participate in the Harvard-Smithsonian Institute field test for the Laboratory for the Study of Exoplanets: Fostering Data Literacy program. This project is a one to two-week program that allows students to use real telescopes that they access online, become competent in image-processing software, and manipulate interactive models to detect and describe other worlds orbiting stars beyond our own solar system. In order to be selected for participation, Mrs. Geddes was required to attend training in the use of the telescope and planet detection software and participate in individual interviews with project staff. Mrs. Geddes explained, “In addition to the training, I had to complete a lot of independent study and practice to ensure I was proficient in remotely interacting with the telescope and using the software, but I knew it would be worth the extra effort to offer this opportunity to my students.”

The Harvard-Smithsonian Institute chose thirty-eight high schools in the United States to field test the exoplanet laboratory. The Creekview students selected their star HATP-36 from a menu of target stars, and then scheduled the telescope to take images of this star. In order to detect a planet, the students measured the brightness of the star over a period of several hours, and from the telltale, periodic dip in the brightness of HATP-36, they were able to develop a portrait of a planet transiting the star. Each student analyzed individual images and then the class combined their data to assemble a complete portrait of the transiting planet. The students then used the Harvard-Smithsonian Institute’s interactive models to predict the size and condition of the planet and determine its distance from the central star.

The students discovered that the exoplanet orbiting HATP-36 is uninhabitable in that it is only five million miles from the star (closer than Mercury is to our Sun). This exoplanet is roughly 20 times the size of the earth and is essentially a giant ball of gas. Ultimately, the students will compare, combine, and communicate these findings with other students, other schools, and with the Harvard-Smithsonian Institute. When asked to describe what he learned from the project, AP Physics student Adam Miles replied, “I had no idea how much we could learn about a planet just by observing changes in brightness of a star. I definitely have a better understanding of the number of planets that exist beyond our own solar system; this was an eye-opening realization!” Fellow classmate Cara Perrin added, “I liked being able to work with real data and images just like professional astronomers.”

Creekview Planet Hunters from left to right. Front row: Chris Hoover, Adam Miles, Bruce Moshier, Cara Perrin, Caleb Lloyd. Back row: Chris Hough, Jesse Wood, Hazel Tuck, Doug Nulph, Bo Roberts, and Liam Ritchie.

# The most poetic thing I know about physics . . . .

## “Every atom in your body came from a star that exploded. And, the atoms in your left hand probably came from a different star than your right hand. It really is the most poetic thing I know about physics: You are all stardust.”

#### Lawrence Krauss

See more astronomy quotes at: http://oneminuteastronomer.com/9380/great-astronomy-quotes/#sthash.cIKFJff6.dpuf

# Lunar-Based Fusion with Helium-3

Photo Credit: http://i297.photobucket.com/albums/mm228/ stem50/Aristarcus_CL_01.png

by: Eric Byrd, Rachel Rogers, and Cora Olson

We have a vision for the future where the Earth could be powered for thousands of years. We believe that the next great power source will be nuclear fusion, but more specifically, nuclear fusion on the Moon. The moon has an estimated 1 million tons of a certain substance that when fused with deuterium would release enormous amounts of energy with little to no radioactive waste as a byproduct. Helium-3 exists in the surface of the Moon. Nuclear power plants on the Moon, fusing He-3 with deuterium, would not only provide almost limitless energy for Earth, but completely eliminate the danger of a nuclear melt-down. This is our vision for the future: these nuclear fusion reactors would generate power that would be sent back to Earth in microwave form and then reconverted back into electricity to be used by the nations of the world.

Present Technology
Nuclear power is nothing new to the world of science; nuclear fission, the act of splitting the nucleus of an atom and releasing energy, is currently being used as a source of energy. Although this method does not contribute to global warming like fossil fuels, this method results in large amounts of radioactive waste which cause adverse health effects if exposed outside of the reactors. With all of the nuclear reactors combined, there are about 2,000 metric tons of radioactive waste being produced each year. We know that Helium-3 would produce a safe, more reliable power source than our current methods of fission as well as other methods of fusion. In nuclear fusion of Helium-3, we would fuse Helium-3 with deuterium, giving off a proton and Helium-4 (Bennet, “Lunar Helium-3 as an Energy Source”). The product of the reaction would weigh less than the reactants, and the missing mass would be converted to energy. It does not produce any nuclear waste in the reaction. The concentration of Helium-3 in the moon’s soil is 13 ppb, which seems like a small number (“Mining the Moon.”); however, we estimate that there are over one million metric tons of Helium-3 on the moon (Bennet, “Lunar Helium-3 as an Energy Source”). One million metric tons of it would produce 20,000 terawatt years of thermal energy (Bennet, “Lunar Helium-3 as an Energy Source”). This is a very large amount of energy- a terawatt consists of one trillion watts.

As of today, fission is more commonly found than fusion. Fission splits atoms, while fusion fuses two atoms. Fission is used more often because fusion requires much more pressure and higher temperatures to happen successfully. Although fission does create energy, it also leaves behind harmful radioactive waste that is extremely harmful to the environment. Fusion also creates much more energy than its nuclear energy counterpart, fission. Because of this, the creation of fusion reactors is constantly being experimented with today as the need for energy sources becomes more urgent. Fossil fuels are being depleted and will soon be gone forever, which is why the making of a successful fusion reactor is critically important for the world. Today, there is progress underway for a commercial fusion reactor to be produced by France called “ITER” (International Thermonuclear

Experiment Reactor). It is estimated that it will produce ten times more energy than it consumes (ITER Organization). This would be the first time a commercial reactor would bring fusion to a large scale of consumers on the market, making safe nuclear fusion as a main power source for the world.

A similar reactor could be constructed on the moon, using Helium-3 instead of the lithium-based fusion being produced under the ITER project. If constructed to be used on the moon, it could effectively use fusion to create vast amounts of energy to be transmitted back to earth. When it comes to transmitting the energy back to Earth, we will use transmitting antennas and rectennas or rectifying antennas. The transmitting antennas will convert the electricity in microwaves then send it to Earth. Then, rectennas will capture microwaves and convert it back into electricity. Rectennas have been proven to work in many experiments and are very effective and have 90% efficiency (Barathwaj. and Srinag.). These antennas and the microwaves they intercept are fairly safe, too; however, transmitting antennas have not been fully proven yet.

Our Vision

We have the technology for getting to the moon, retrieving the Helium-3 and transmitting the fused energy back to Earth in microwaves. We only need to be able to produce high temperatures in a vacuum. These reactors will be on the moon along with a place to process Helium-3 and separate it from the soil. Other future technology could be fusion reactors that use solely Helium-3 in reactions. This energy would be transformed directly into electricity (“Mining the Moon.”).

Other future technology would be improved rectennas and transmitting antennas. The transmitting antennas would have a higher efficiency in converting electricity into microwaves and would also be able to reduce the amount that the beamed electricity would spread as it traveled through space. They would also be able to transmit even further distances, possibly deep into our solar system or beyond our galaxy. Rectennas would have a higher efficiency, reaching close to 100% and would take up less space on land to capture the microwaves. These rectennas will be placed across the globe so that energy could be sent anywhere at any time.

With the ITER project still underway, future research for a similar commercial reactor could be created with Helium-3. When created, this type of reactor could be used in our idea of lunar-based fusion, replacing the need for lithium and using Helium-3 once it is implemented on the moon. Although ITER is still in preliminary stages of design, it could become very useful as a revolutionary product, especially if it is manipulated for receiving energy from the moon. The reactor would not only have to be changed to be able to process Helium-3 efficiently, but it would also need to create energy transmittable through microwaves. When created, the reactor would have to be able to operate with little to no human support, which is important considering the high price of moon travel. As a commercial reactor, this product could contribute to an abundance of energy to the world.

The breakthrough in science required for this vision to be realized is being able to fuse Helium-3 and deuterium. At this moment in time, scientists are able to fuse tritium and deuterium because they fuse at low levels of energy. The energy required to fuse helium-3 and deuterium is twice the amount that we are currently able to achieve. This is a huge obstacle to overcome, but the fact that we are half-way there is promising. Another needed break through is a method for extracting large amounts of Helium-3 from the soil with a minimum output of energy. The soil must be heated to a high temperature, roughly 600 degrees Celsius, to extract the Helium-3, and though we do already have this technology, we would need a way to sustain energy on the moon so that enough of the substance can be extracted to make a practical amount of energy (Bennet, “Lunar Helium-3 as an Energy Source”). Finally, the major breakthrough required for nuclear fusion on the Moon to provide energy for Earth is the ability to convert electricity into microwaves with practical efficiency.

Conclusion

It only takes twenty-five metric tons of Helium-3 to power the United States for one year at its current energy consumption rate (Horton). If the estimate of over one million tons of Helium-3 on the moon is accurate, then it would be enough to power the U.S. for 40,000 years because only twenty-five tons is necessary to power the whole U.S. for an entire year (Bennet, “Lunar Helium-3 as an Energy Source”). Lunar-based fusion with Helium-3 will lead the US and the world to safe and sustainable power for tens of thousands of year.

Bibliography
Bennet, Gregory. “Artemis Project: Helium-3 Overview.” The Artemis Project. Artemis Society International, n.d. Web. 16 Nov. 2012. <http://www.asi.org/adb/02/09/he3-overview.html&gt;.

Bennet, Gregory. “Artemis Project: Lunar Helium-3 as an Energy Source, in a Nutshell.” Artemis Project: Lunar Helium-3 as an Energy Source, in a Nutshell. Artemis Society International, n.d. Web. 16 Nov. 2012. <http://www.asi.org/adb/02/09/he3-intro.html&gt;.

D’Souza, Marsha R., Diana M. Otalvaro, and Deep Arjun Singh. Harvesting Helium-3 from the Moon. Rep. no. IQP-NKK-HEL3-C06-C06. N.p., 17 Feb. 2006. Web. 3 Dec. 2012. <http://www.wpi.edu/Pubs/E-project/Available/E-project-031306-122626/unrestricted/IQP.pdf&gt;.

Freudenrich, Ph.D., Craig. “How Nuclear Fusion Reactors Work” 11 August 2005. HowStuffWorks.com. 16 November 2012.

G, Barathwaj., and Srinag. K. Wireless Power Transmission of Space Based Solar Power. Rep. Vol. 6. Singapore: LACSIT, 2011. IPCBEE. International Proceedings of Computer Science and Information Technology, 2011. Web. 11 Dec. 2012.

Horton, Jennifer. “Can We Harness Energy from Outer Space?” HowStuffWorks. HowStuffWorks Inc., N.d. Web. 03 Dec. 2012.
ITER Organization. “ITER – the Way to New Energy.” ITER – the Way to New Energy. ITER, n.d. Web. 11 Dec. 2012. <http://www.iter.org/proj&gt;.

“Mining The Moon.” Popular Mechanics. Hearst Communication Inc., 7 Dec. 2004. Web. 03 Dec. 2012. 11Project No. 407A, Lunar-Based Fusion with He-3

“Nuclear Fission (physics).” Encyclopedia Britannica Online. Encyclopædia Britannica Inc.,
n.d. Web. 16 Nov. 2012. <http://www.britannica.com/EBchecked/topic/421629/nuclearfission/48303/History-of-fission-research-and-technology&gt;.

“Outline History of Nuclear Energy.” History of Nuclear Energy. World Nuclear Association, June 2010. Web. 16 Nov. 2012. <http://www.world-nuclear.org/info/inf54.html&gt;.
Teitel, Amy S. “Pillaging the Moon for the Promise of Space Energy.” Diiscovery News. Discovery, 3 Sept. 2012. Web. 16 Nov. 2012. <http://news.discovery.com/space/spaceenergy-mining-the-moon-120907.html&gt;.

# Using Backyard Astronomy to Verify Kepler’s Laws

by Patrick James and Nolan Williams

Kepler’s first law implies that the Moon’s orbit is an ellipse with the Earth at one of the foci. By observing the moon over a month’s time we can plot its orbit and then use this data to analyze the shape of the orbit. We used a Vixen astronomical telescope equipped with a Meade MA 12mm illuminated reticle to observe the moon each day of its orbit to prove that the moon follows Kepler’s First Law. The location where we made measurements and observations of the moon was from a residential driveway because of the clear visibility of the night sky and the convenience of the location.

In order to gather data, we first had to locate the moon in the sky with the telescope. Once located, we used the focus of the telescope to make sure the image of the moon was clear. Then we positioned the scale of the reticle over the widest point of the moon and took the measurement of the moon’s diameter. We repeated this process two more times, thus yielding three independent measurements for each night. Next, we averaged the three in order to give a more accurate measurement for the night.

On the first night of making observations, the moon was at apogee and was in the western sky. Using the reticle, we measured its apparent diameter to be about 51 mm. Over the next several days, the moon’s diameter increased slowly from about 51mm to 53mm. The moon’s orientation in the night sky changed from the West to the South. After a week of being unable to take measurements during spring break, we found the moon’s diameter had increased from 53mm to 58mm. The moon was still in the southern sky at night, but a few days later it was only visible in the morning.

On April 4, 2012, the moon reached perigee. and its diameter was about 59mm and it was sitting in the southwestern sky. After another few days, the moon’s diameter slowly decreased from 59mm to 57mm. Unfortunately, there was a period of time where the moon wasn’t visible due to the weather; however, this did not skew the data. On the last day of observations (April 25, 2012), the moon was at apogee and its diameter was once again 51mm, but was in the eastern sky instead of the western sky.

From the observations, we could see that the moon’s apparent diameter changed from a minimum of 51mm to a maximum of 59mm (and then back to 51mm). We plugged the data into an observation spreadsheet, which would take the diameter measured on the reticle and convert it to the actual diameter of the moon based on the focal length of the telescope. The spreadsheet then converted the diameter into the position coordinates of the moon and then graphed these coordinates. This gave us a plot of the orbit of the moon. I was then able to fit an ellipse to the plot of orbit of the moon and show that the orbit is elliptical.

After a month of observing, we were able to successfully prove Kepler’s First Law. The best fit line to the plot of the orbit was an ellipse, thus showing that planetary orbits are not circular, but elliptical as Johannes Kepler stated hundreds of years ago (amazing!). Although we were successful in our task, there are various possible sources of error. One of the sources of error could be human error. The measurements we took were all taken by looking at a scale imposed on the moon by very inexperienced observers. This could have resulted in some inaccurate measurements, but by using multiple measurements by multiple people each night, this error was hopefully reduced. Also, there were several days throughout the month where it was impossible to collect data due to bad weather. This could have affected the plot of the orbit; however, because we only missed a few days of observing, we can assume the error to be negligible. Overall, this was an awesome experience, it was amazing to be able to analyze and observe such huge objects and forces in motion!

# Channels on Martian Surface Still a Mystery

by Sequoyah High School 2012 1st period honors physics students (students are listed by name at the end of the article).

Since humans first looked up and pondered the heavens, mankind has contemplated the possibility of life beyond Earth. From Kepler’s 1634 science fiction account of travelling to the moon in his book The Dream to H. G. Wells’ The War of the Worlds, and even popular blockbusters such as Mars Attacks and Men in Black, man’s fascination with space and the possibility of the life-forms that dwell there is well documented. NASA’s Odyssey Program now allows humankind to search beyond the limits of Earth’s atmosphere and beyond Earth’s moon to discover a planet that exhibits similarities with Earth.  One of those similarities is the presence of water, “a necessary condition for the emergence of life” (NASA Astrobiology Institute, 2007).  Since water is a necessary condition for life, the Sequoyah High School Honors Physics students sought to obtain evidence to determine the presence of water on the Martian surface. The research question was, “Among channels existing on the surface of Mars, how prevalent are those exhibiting evidence of origins in fluvial systems rather than volcanic flow?”

Channels provide evidence of flowing liquid which could possibly have been water, and the existence of water indicates that certain life-forms could be possible. Also, the presence of water on Mars provides a similarity with Earth and allows researchers to better understand the relationship between the history of Mars and the future of Earth. The hypothesis for this research is, Images of channels on the Martian surface and the examination of characteristics of those channels will indicate that some were created by water flow.

# Background

Mars is a frozen desert, filled with dry dust, and apparently void of life, so it is surprising that Mars and Earth share some common characteristics.  Mars is very similar to Earth in that it has an atmosphere, albeit much less dense than Earth’s, and this atmosphere produces clouds and wind (Miles and Peters, 2008).  Also, Mars and Earth possess polar ice caps; however, the NASA probe Mariner 7 revealed that the Martian ice caps are carbon dioxide (dry ice) instead of water (Watt, 2002, pg. 6).  NASA researchers postulate that water ice is buried below the dry ice but efforts to prove this point have not been successful (Watt, 2002, pg. 15).  Recent evidence does support that flowing water did exist on Mars sometime during its history, and water in the form of ice may still exist today (Arizona State University Mars Space Flight Facility, n.d.).

Characteristics of Mars’ surface that would indicate past or present existence of water are “small islands, secondary channels that branch off and rejoin the main one and eroded bars on the insides of the curves of the channels” (Zubritsky, 2010). The history of the channels is still unclear, but the widely held belief is that water carved some of the channels present on Mars’ surface. Additionally, studies suggest that lava systems could potentially form the same channels. Scientists, under a team lead by Jacob Bleacher, examined lava flows on Earth and determined that those flows could also produce terraced walls; however, the team said their findings did not rule out the possibility for the existence of water on the surface (Zubritsky, 2010).

Indeed, chemical analysis goes against Bleacher’s hypothesis on the history of the channels on Mars. When the Phoenix Mars Lander arrived on Mars, it was able to collect samples of soil to analyze before the lander stopped working. Mars’ atmosphere is thinner than Earth’s, so carbon is lost to space. Scientists would expect that the atmosphere of Mars would be heavily depleted of Carbon-12 and made primarily of heavier Carbon-13; however, the analysis done by the Phoenix showed large amounts of Carbon-12, suggesting the carbon was replenished recently. An even more surprising finding was the presence of oxygen isotopes in the Martian atmosphere. Scientists cite the presence of oxygen as evidence of liquid water on Mars in recent history because the carbon dioxide reacted with oxygen (Webster & Jeffs, 2010).

Certain images of Mars indicate that water or other liquids once flowed on the surface of Mars creating channels and gullies.  The channels are characterized by a branching pattern, referred to as a dendritic pattern, associated with water flowing.  These channel systems have been found in the Echus and Melas Chasma regions of Mars. Scientists also speculate that snow or rainfall could have contributed to the flowing water (Arizona State University Mars Space Flight Facility, n.d.). The fact that these channels form meandering patterns in much the same fashion as water channels found on Earth suggests that similar factors are causing these channels to form on both planets. Meandering fluvial systems on Earth are often the result of vegetation creating a trap for sediment to discourage erosion which in turn causes the channels to snake throughout the landscape. Although Mars lacks this type of vegetation, scientists believe that the clay sediment found on Mars, in addition to microbial crusts found on the surface, provides the same cohesion required to prevent erosion and make the channels curve. With this evidence in mind, the theory that water once flowed through the channels is still sound even without the specific circumstances outlined by the water systems on Earth. Scientists speculate that “large meteor impact or volcanic eruption” could have “melted ice and created a wet micro-climate for a short period of time in the recent past” (Schirber, 2009). The occurrence of large impact craters could have contributed to flooding that resulted in the channel formation seen on Mars today. “The force of the impact melted the permafrost . . . . and caused the resulting water to flow violently away from the crater” (Watt, 2002, pg. 17-18).

When evaluating images of channels, one must discern the differences between channels formed by lava flow and those formed by the flow of water.  Also, certain characteristics of channels resulting from water flow give clues to the amount of water present.  The channel walls, floors, and tributaries may be analyzed to determine water volume (Watt, 2002, pg. 18).

Figure 1, THEMIS Image No. V11030007 provides insight into the differences between channels formed by lava flow and those formed by water.  This figure is a THEMIS image of a section of the channel system Hebrus Vallis. The perpendicular flow of channels apparent in this image is not associated with fluvial systems and is more indicative of a channel system formed by flowing lava.  Indeed, Hebrus Vallis originates close to the base of the Elysium volcanic complex and was likely formed by volcanic activity (Christensen, 2004, Image No. V11030007). Lava channels are also characterized by rafting where hard pieces of crust harden and create a damming effect, thus causing the lava to sharply change its flowing pattern and in many cases create perpendicular channels (Swann, 2012), and generally, multiple lava flows occur in one image (Mars Student Imaging Program, 2007).

A channel indicating water flow is provided in Figure 2, THEMIS Image No. V03701003, a section of the Minio Vallis Channel (Christensen, 2004, Image No.  V03701003). Channels formed by water flow exhibit a meandering shape. Typically, these patterns are formed by water flow responding to resistance to erosion on the surface, whereas lava simply cuts through and branches off abruptly. Conversely, water creates main channels that have secondary channels branching off and rejoining the main one.

## Methods

Data was collected via the Thermal Emission Imaging System (THEMIS), a camera onboard Mars Odyssey, capable of producing images with both visible and infrared light.  Utilizing visible imaging, the instrument is capable of “20-meter resolution measurements of the surface,” and infrared data may be used to enhance the visual images (Watt, 2002, pg. 42). The image data was collected via real-time streaming from the current orbital location of Mars Odyssey.  Two images were received from the THEMIS camera; however, only one of the images was able to be analyzed due to dust distortion of the other picture.

The research focused on the presence of channels and specifically whether those channels were formed by lava or water flow. Specific criteria were applied to determine the cause of formation of the channels in the image collected and surrounding area. These criteria were:

Features indicating past water flow

Primary Criteria

• Dendritic Patterns
• Meandering patterns in much the same fashion as water channels found on Earth
• Smooth transitions from channel bed to surrounding area

Secondary Criteria

• Secondary channels that branch off and rejoin the main one
• Streamlined islands

Features indicating past lava flow

Primary Criteria

• Lava flows 90o perpendicular out of the channels
• Multiple lava flows in one image.
• Abrupt bump in the transition from channel bed to surrounding area

Secondary criteria

• Abrupt changes in channel direction

The transition from channel bed to surrounding area was surmised using JMARS to develop elevation views of the identified channels. An example of a smooth transition indicative of a water channel is provided to the left as a standard for comparison.  This graph was developed using the JMARS MOLA 128ppd Elevation feature for a channel occurring at 337.75E, 8.625 N. Likewise, the figure below, developed using the same feature illustrates a typical transition for a lava channel.

Our target image was qualitatively analyzed and significant features such as the characteristics of the channels that support its formation by water or lava were labeled on the image (See THEMIS target image in Data). The area surrounding the target image was analyzed qualitatively in a similar fashion and MOLA elevation views were generated to evaluate the channel bed transitions. The JMARS images and MOLA elevation views are provided in the Data section. The information and data collected were organized according to the following table:

 Image   ID No. Lat.   (N) Long.   (E) Channels   (Y/N) Specific   observations of feature Formed   by Lava or Water?

## Data

We collected 2 THEMIS images but were only able to use one of them due to dust distortion of one of the images. The location of the Martian surface depicted in the THEMIS target image is shown on the following Google Mars image (Google Mars, 2012):

The observations resulting from the qualitative analysis are labeled on the THEMIS image shown on the right.

The table below the image delineates the features that were observed in the surrounding areas of our target image of Martian surface.

 Table 1: Observations Image ID No. Lat. (N) Long. (E) Channels (Y/N) Specific observations of feature Formed by lava or water? V46057015 18.662 184.154 Y Streamlined islands, Meandering patterns Water JMARS 11.375 181.25 Y Streamlined islands, Meandering patterns, 1 perpendicular channel Indeterminate.First two observations indicate water; 3rd indicates lava. JMARS 18.125 185 Y Streamlined islands, Meandering patterns Water JMARS 32.339 165.005 Y Meandering patterns. Abrupt transition across channel bed Indeterminate; displays characteristics of both. JMARS 18.586 184.194 Y Meandering patterns. Smooth transition across channel bed. Secondary channels branch off and re-join main channel. Streamlined islands. Water JMARS 12.75 182.625 Y Dendritic patterns. Secondary channels branch off and re-join main channel. Streamlined islands. Abrupt transition across channel bed. Abrupt changes in channel direction Indeterminate; displays characteristics of both. JMARS 11.590 N 180.746 Y Secondary channels branch off and re-join main channel. Streamlined islands. Abrupt transition across channel bed. Indeterminate; displays characteristics of both.

Table 2: Sample images and corresponding elevation views

 Location JMARS image MOLA Elevation View 165.005 E, 32.339 N 184.194 E, 18.586 N 182.625 E, 12.75 N 180.746 E, 11.590 N 183.834 E, 16.303 N

# Discusson

As shown in Table 1 of the Data section, the THEMIS image displays characteristics that provide evidence of the past existence of fluvial systems.  These characteristics include very wide, shallow channels, streamlined islands, and meandering patterns; however, features in the surrounding area indicate evidence of lava systems.  One of those features is rafting, a condition associated with lava flow that is typically indicated by 90o bending of the channel (indicated in JMARS 11.375N and 181.25E). Our observation of rafting indicates that the characteristics of this area do not support water formation. All other surrounding areas that we analyzed were either indeterminate or indicated water formation. Out of the 7 areas analyzed, 4 areas were indeterminate with respect to cause of channel formation. While there is evidence supporting fluvial systems in our target THEMIS image, there is not enough evidence from the surrounding area for us to conclude our channel was created by water flow.

Based on images of the area surrounding our THEMIS image and the MOLA elevation maps, we have decided that the data is inconclusive.  Features found in the images and elevation maps contained characteristics of both water and lava. While most of the elevation maps leaned toward lava, there were features that were characteristic of water in the JMARS images. Since the area displays evidence of both fluvial and lava systems, it is possible that a volcanic eruption could have melted ice and created a system of water and lava as described by Schirber (2009), but future work is needed before this conclusion can be drawn.

When collecting our data, errors may have occurred due to a few factors. Inaccuracies could have occurred because of the inexperience of the student researchers.   Being in high school, the researchers have not had much exposure to Mars and its features, and this was our first experience interpreting satellite images and using JMARS.  Also, at the time the images were taken, there was a dust storm on Mars that prevented one of our images from being analyzed. Our data could have been misinterpreted because of the student researchers’ bias towards water systems.  Our question addresses the prevalence of fluvial systems, so there is a possibility that we were leaning towards fluvial systems over lava.

# Conclusion

This project allowed the Sequoyah High School Honors Physics students to investigate evidence to address mankind’s persistent curiosity about the potential for life on Mars.  Specifically, the research effort focused on the presence of water since water is a necessary condition for life. Since the presence of channels provides evidence concerning the existence of water, the research was driven by the question, “Among channels existing on the surface of Mars, how prevalent are those exhibiting evidence of origins in fluvial systems rather than volcanic flow?”  The hypothesis developed was: Images of channels on the Martian surface and the examination of characteristics of those channels will indicate that some were created by water flow. Based on the evidence found in our target image and a thorough examination of the surrounding area, we are unable to conclude the exact method of formation of the channels that we reviewed because they displayed features of both water and lava systems.

The research question was developed with the goal of gaining an understanding of the relationship between life-sustaining water on Earth and the presence of water on Mars. Understanding this relationship offers insight into the future of our planet based on the history of Mars and the fate of Martian fluvial systems. Unfortunately, our data were inconclusive and more work is necessary to accurately determine the cause of channel formation in our target area of the Martian surface. If we expanded our surrounding area, we might find evidence of volcanic systems or impact craters that would provide more insight into the history of our area. Additionally, investigating the history of weather phenomena in our area could provide more evidence to assist in establishing more definitively the origins of the channel systems in our target area.

# Acknowledgements

The Sequoyah High School Honors Physics class would like to acknowledge and thank our teacher Mrs. Geddes for providing mentorship and guidance for this project. We would also like to thank Jessica Swann of the Mars Space Flight Facility for her dedication to our efforts.

The students of the Sequoyah High School 2012 1st period honors physics are: Michelle Blankinship, Deanna Cape, Megan Cargin, Cody Copeland,  Tori Falco, Bobby Flanagan, Joe Garcia, Christina Herd, Natalie Hopkins, Stephen Ibar, Emily Kidd, Lauren LoPiccolo, Megan Pace, Connor Reeder, James Rogers, Priscilla Rojas, Megan Simms, Anna Singh, Haley Smith, Ayana Thomas, Yulian Vieta, Kristin White, and Derek Willingham.

# References

Arizona State University Mars Space Flight Facility. (n.d.). Mars has more channels than previously thought. Retrieved April 3, 2012, from Mars Odyssey THEMIS: http://themis.asu.edu/node/5399

Christensen, P.R., N.S. Gorelick, G.L. Mehall, and K.C. Murray. THEMIS Public Data Releases, Planetary Data System node, Arizona State University, <http://marsed.asu.edu/files/MSIPResourceManualv200.pdf&gt;.

Google Mars. (2012). 18.622 N and 184.154 E Retreived May 21, 2012.

Mars Student Imaging Program. (2007, May 31). Feature ID Chart.  Retrieved April 3, 2012, from Welcome to the Mars Student Imaging Program: http://marsed.mars.asu.edu/files/msip_resources/FeatureIDCharts.pdf

Miles, K. and Peters, C. (2008). The Martian Atmosphere. Retrieved April 3 2012, 2012, from Starry Skies: http://starryskies.com/solar_system/mars/martian_atmosphere.html

NASA Astrobiology Institute. (2007, December 21). Is Water Necessary for Life? Retrieved April 3, 2012, from Astrobiology: Life in the Universe: http://astrobiology.nasa.gov/nai/seminars/detail/161.

Schirber, M. (2009, December 10). The meandering channels of mars. Retrieved April 12, 2012, from Astrobiology Magazine: http://www.astrobio.net/exclusive/3337/the-meandering-channels-of-mars.

Swann, J. (2012, April 18), Education and Technology Specialist with Mars Space Flight Facility, in a teleconference with Sequoyah High School Honors Physics Students.

Watt, K. (2002). Mars Student Imaging Project: Resource Manuel. Retrieved June 29, 2006, (April 3, 2012) from Arizona State University, Mars Student Imaging Project Web site: http://msip.asu.edu/curriculum.html.

Webster, G. &. (2010, September 9). NASA Data Shed New Light About Water and Volcanoes on Mars. Retrieved April 12, 2012, from http://www.nasa.gov: http://www.nasa.gov/mission_pages/phoenix/news/phx20100909.html.

Zubritsky, E. (2010, March 4). Lava likely made river-like channel on Mars. Retrieved April 12, 2012, from http://www.nasa.gov: http://www.nasa.gov/topics/solarsystem/features/mars-lava-channels.html.