# 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.

# 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!