Sky Journel #5

October 18
Time: 5:45PM
Location: Eagle Drive, Burlington, WA

            The weather was too bad this week to be able to see anything so I made it a point to watch the sunset instead. There isn’t much to say about it. It was pretty orange and pink in color and was at about 290⁰ West.

Sky Journel #4

Date: October 12, 2010
Time: 1:30 AM
Location: Arbor street, Mount Vernon, WA

The picture below is a  replica I made of the sky as I saw it a couple nights ago (note that East is on the top, West the bottom, etc. because I was not facing North and this way is less confusing for me). The points have been drawn fairly large so that they’re able to be seen.
            One constellation I think I saw was Auriga (labeled a on the “map”). Auriga has a really bright star as one of the points of its circle-like head which I was able to make out but I didn’t see any parts of the tail. The azimuth was about 40⁰ (northeast) and the altitude 15⁰.
            Secondly, I thought I was looking at Cassiopeia (labeled b) but I often get it the larger W-shaped constellation confused with it. The azimuth was 350⁰ (northwest) and the altitude was 40⁰.
            There were other stars out obviously but they were all pretty small and not very identifiable for me.

Sky Journel #3

Date: October 7, 2010
Time: 12:15 AM
Location: Arbor Street, Mount Vernon, WA

The picture below is a  replica I made of the sky as I saw it last night (note that East is on the top, West the bottom, etc. because I was not facing North and this way is less confusing for me). The points have been drawn fairly large so that they’re able to be seen.
            The most predominant constellation I could see was Ursa Major (labeled a) though I was not able to see all points of the constellation due to Washington’s infamous weather. The azimuth of Ursa Major from my location was about 350 ⁰ (north) and the altitude was about 40⁰.
            The only other constellation that I was able to make out was what looked to be pieces of Cetus (labeled b). I was able to see most of the points of the smaller pentagon, the connecting star and the tip of the large pentagon-like shape. The azimuth of Cetus from my location was 180⁰ (south) and the altitude was about 40⁰.
            In addition to constellations, I was able to see a fairly bright star which I though could possibly be the bright point on the constellation Cygnus (labeled c) which had an azimuth of 280⁰ (northwest) and an altitude of 65⁰.
            Lastly, I saw another bright star close to Cygnus but I think it was too bright to be part of Cygnus and I determined it was a bright point of the constellation Lyra. This star had an azimuth of 285⁰ (northwest) and an altitude of 65⁰.

Properties of the Sun Lab Write-Up

Problem: Use images of the Sun to find the rotation period of the Sun, and to find the velocity of matter leaving the Sun through a coronal mass ejection.

Hypothesis: It was my guess that we could determine the velocity of a coronal mass ejection because we had a way to determine distance and had photos that were representational of time but I figured our method would not give us the most accurate measurement as there is a fair amount of room for error.

Procedure #1: The following are the steps used for our first procedure: 1) we determined the diameter in pixels using the image of the sun. 2) We looked up the actual diameter and divided the actual diameter in km by the measured diameter in pixels and determined a km/pixel image scale. 3) We measured the distance in pixels that the coronal mass ejection moved and multiplied that number by our scale factor to determine the distance the mass ejection moved. 4) We used our calculations to determine the period of the sun in days.

Procedure #2: The following are the steps used for our second procedure: 1) we determined a new image scale by measuring the diameter of the sun in pixels and dividing the actual diameter of the sun in km by the pixel diameter. 2) We pinpointed both of the minimum heights in pixels of the mass ejections, used the distance formula to determine the pixel distance moved and then converted that number to km using our scale factor. 3) We pinpointed both of the maximum heights in pixels of the mass ejections, used the distance formula to determine the pixel distance moved and then converted that number to km using our scale factor. 4) We used our calculated distances to determine the change in height in km. 5) We used the times recorded below each picture to determine the time change. 6) We divided our calculated distance covered by the time it took for the mass ejection to move that distance and found the velocity of the material in km/h. 7) We converted our velocity to mi/hr.

Data & Calculations: Can be seen on the hardcopy of the lab which will be turned in on the day of the test.

Conclusion: We were able to determine the velocity of the coronal mass ejection using simple pictures, pixel measurements and formulas which was interesting.  We determined that the material left the sun at an extremely fast velocity when compared to the velocity of things we are familiar with like cars and airplanes which is kind of mindboggling to think about. As with all labs there was some error in our calculations. This error came from unsteady hands used to determine pixel location as well as small photos that do not allow for very precise measurements.

Weekly Reflection: 10/18-10/22

Most of my time spent this week was spent filling in missing holes on all my labs, filling out the write-ups and working through the different assignments, projects and worksheets. I found my solar research and listening to the solar research of others to be interesting and informative because I have never really thought about what the sun looks like or is composed of which is why I also found the lectures to be interesting. My aha moment was realizing how much there actually is going on in the sun and on the surface of the sun. Another aha moment was when I did my solar research and learned how coronal holes on our sun that is so far away can actually affect our communication. Finally, I enjoyed the different APODs because I think pictures of the solar system are always really pretty as they are so colorful and something that is fairly unfamiliar to me.

Identifying Lines in the Solar Spectrum Lab Write-Up

Problem: The purpose of the lab was to identify lines of the solar system using Fraunhofer lines.

Hypothesis: As this lab was primarily data collection there was not much to hypothesize.

Procedure: We used a picture we were provided with to pinpoint the pixel location of two separate lines and found the pixel distance between the two. From there we used the table we were provided with to find the distance in nanometers and used nm/pixels to establish a scale factor. Our next step was to identify unknown lines along the same spectrum. We first chose one line to serve as our reference point and determined the pixel location and the given wavelength in nanometers. We then found the pixel location of each line and determined the distance between that line and the reference point. Next, we multiplied the pixel distance by our previously calculated scale factor to get the wavelength in nanometers of each element. From this point we were able to use the wavelength to determine the element name of each unknown line.

Data: Can be seen on the hardcopy of the lab that will be turned in on the day of the test.

Calculations: Can be seen on the hardcopy of the lab that will be turned in on the day of the test.

Conclusions: We were able to determine some of the different elements in the solar spectrum however our calculations could not be entirely accurate. Because we were using unsteady hands and trying to pinpoint small lines there is some error in our pixel determination which is the foundation on which all other questions and calculations are based. We saw this error come into play when we used the calculated wavelength to determine the name of the element but it was obvious that our calculations were off a bit because none of the elements had the exact wavelength that we calculated so we had to round our numbers to the element with the closest wavelength. Error aside, it was interesting to see how we could use something as simple as a picture on a computer screen to determine different elements and wavelengths.

Solar Research: Question #6

In 1973 the United States launched its first space station, Skylab. Skylab was in the Earth’s orbit for about six years (from 1973-1979) and was equipped with x-ray telescopes to reveal the structure of the sun, specifically the corona of the sun. These x-ray images taken from both the Skylab and other satellites revealed the sun to have darker, colder spots on its corona that can be as large as the earth’s diameter and have plasma with lower density than average. We have since learned that coronal holes occur when the magnetic field of the sun is open to interplanetary space and there are regions on the sun where solar magnetic fields loop back to the sun forming arches which are depicted on x-rays as brighter areas than the rest of the corona.
            We should care about coronal holes because open configuration of the magnetic field allow particles to escape into space and research has found that coronal holes are the source of high speed solar wind streams which, when coming in contact with the Earth, can cause geomagnetic storms. Periods of high amounts of solar activity eject mass from the coronal holes and periods of low solar activity geomagnetic storms are created. From our perspective, it is important to monitor solar activity in and from coronal holes because these holes can last for several months and following them gives us the ability to predict geomagnetic disturbances

Image: http://sprg.ssl.berkeley.edu/~hhudson/drafts/sw10/sch.pdf

Darling, David. "Coronal Hole." The Worlds of David Darling. 1999. Web. 21 Oct. 2010. <http://www.daviddarling.info/encyclopedia/C/coronal_hole.html>.

Solar System APOD: Saturn's Moon Helene from Cassini

http://apod.nasa.gov/apod/ap100310.html

          My APOD of the solar system (credit to NASA/JPL/SSI) features Saturn’s moon Helene, a smaller moon that is the sixth farthest from Saturn.  Helene was discovered using ground-based observations in 1980 and was named after Helen of Troy in 1988 who was the granddaughter of Cronus (Saturn) in Greek mythology.  One theory is that Helene was formed from material in the rings being clumped together. This conflicts with the Solar Nebular Theory because scientists found that Helene is actually less dense than an asteroid and is not composed of dust and gas as the theory suggests. I really just chose this picture because Helene is in the solar system and because I think the light and shadowing of the picture is cool. I also think it’s cool that they were able to get so close to the moon (within two Earth diameters) and get us this good close-up picture.

Bergman, Jennifer. "Helene." Windows to the Universe. National Earth Science Teachers Association, 19 Jan. 2001. Web. 21 Oct. 2010. http://www.windows2universe.org/saturn/moons/helene.html

Edwards, Lin. "Formation of Saturn's Ring Moons Explained." PhysOrg.com - Science News, Technology, Physics, Nanotechnology, Space Science, Earth Science, Medicine. PhysOrg.com, 10 June 2010. Web. 21 Oct. 2010. <http://www.physorg.com/news195368117.html>.

Meteorite Lab

Problem: Can we calculate the size of Canyon Diablo Meteorite by using simulation?

Hypothesis: I figured that the size of the Canyon Diablo Meteorite could be roughly calculated but the error percentage would be really high because we cannot take into consideration the speed it hit the earth at or how far the meteorite was falling from.

Procedure: We filled a box with flour and some cocoa (for color differentiation) and dropped a marble from one meter five times each and then we dropped another marble from the same high five times. With each drop we measured the size of the diameter of the crater from the very outer edge to the opposite outer edge. From this point we used the ratio given to us on the lab to cross multiply and get an estimate on what the diameter of the Canyon Diablo Meteorite might have been.

Data: Can be seen on the hardcopy of the lab which will be turned in on the day of the test.

Calculations: Can be seen on the hardcopy of the lab which will be turned in on the day of the test.

Conclusions: We concluded that simulation can give us an idea of the size of Canyon Diablo Meteorite but the calculations of my group were not very accurate. I think one possible reason for this is the precision of the calculations. If we had measured the diameter of the crater made to the tens of thousandths place we would have more accuracy.

Spectra Lab

Problem: The purpose of this lab was to use spectrometers to look at various heated elements as well as the sun and fluorescent lights and observe the emission, absorption and continuous spectrum of the elements.

Hypothesis: I expected that none of the elements would give off a continuous spectrum though I thought the sun would and I did not know what to expect of the fluorescent lights though I figured it would be similar to that of the elements.

Procedure: We used spectrometers to look at the elements, the sun and the fluorescent lights and recorded the lines that were given off or absorbed by each element.

Data: See the hardcopy of the lab that will be turned in on the day of the test.

Calculations: See the hardcopy of the lab that will be turned in on the day of the test.

Conclusion: I learned that all the heated elements we observed gave off emission lines, the sun gives off a continuous spectrum and fluorescent lights give off an absorption spectrum. I thought it was really interesting to actually see the colors that the different elements give off and it really gave me a feel for how simple it is to use spectrums to identify elements.

Satellite Motion Lab Part 2

	Period (s)
Mass (kg)	1	2	3	Average
0.50	0.33	0.33	0.33	0.33
0.30	0.36	0.35	0.39	0.37
0.20	0.43	0.44	0.47	0.45
0.10	0.66	0.66	0.67	0.67
0.05	0.82	0.96	1.00	0.93

As I cannot get my scatter plots to paste here I will turn them in on the test day with the rest of my homework.

Calculations: We were instructed to use our data to calculate the mass of the rubber stopper (the “satellite” in this experiment) and find the percent error as compared to the measured mass of the stopper. Because we used five different radii in our data collection I am going to do five separate calculations of the mass of the stopper and our percent error.

1.      Velocity=distance/time

 =2´p´0.20 ² / 0.28 = 4.5 m/s ²

                         Centripetal acceleration=velocity² / radius

                                                    =4.5 ² / 0.20 = 101

            Centripetal force=mass ´ centripetal acceleration

            (0.20 kg ´ 9.8 m/s)=mass ´101

                                  1.96=mass´101

                                 Mass=1.96/101

                                 Mass=0.019 kg

            % Error=(calculated-actual)/calculated

                        =(0.019-0.026)/0.019

                        = -0.37

                        =37% error

2.      Velocity=distance/time

 =2´p´0.30 ² / 0.34 = 5.5 m/s ²

                         Centripetal acceleration=velocity² / radius

                                                    =5.5 ² / 0.30 = 100.8

            Centripetal force=mass ´ centripetal acceleration

            (0.20 kg ´ 9.8 m/s)=mass ´100.8

                                  1.96=mass´101

                                 Mass=1.96/101

                                 Mass=0.019 kg

            % Error=(calculated-actual)/calculated

                        =(0.019-0.026)/0.019

                        = -0.37

                        =37% error

3.      Velocity=distance/time

 =2´p´0.40 ² / 0.43 = 5.8 m/s ²

                         Centripetal acceleration=velocity² / radius

                                                    =5.8 ² / 0.40 = 84.1

            Centripetal force=mass ´ centripetal acceleration

            (0.30 kg ´ 9.8 m/s)=mass ´84.1

                                  1.96=mass´84.1

                                 Mass=1.96/84.1

                                 Mass=0.023 kg

            % Error=(calculated-actual)/calculated

                        =(0.023-0.026)/0.023

                        = -0.13

                        =13% error

4.      Velocity=distance/time

 =2´p´0.5 ² / 0.46 = 3.4 m/s ²

                         Centripetal acceleration=velocity² / radius

                                                    =3.4 ² / 0.50 = 46.2

            Centripetal force=mass ´ centripetal acceleration

            (0.30 kg ´ 9.8 m/s)=mass ´46.2

                                  1.96=mass´46.2

                                 Mass=1.96/46.2

                                 Mass=0.042 kg

            % Error=(calculated-actual)/calculated

                        =(0.042-0.026)/0.042

                        = 0.38

                        =38% error

5.      Velocity=distance/time

 =2´p´0.60 ² / 0.49 = 4.6 m/s ²

                         Centripetal acceleration=velocity² / radius

                                                    =4.6 ² / 0.50 = 42.3

            Centripetal force=mass ´ centripetal acceleration

            (0.20 kg ´ 9.8 m/s)=mass ´42.3

                                  1.96=mass´42.3

                                 Mass=1.96/42.3

                                 Mass=0.046 kg

            % Error=(calculated-actual)/calculated

                        =(0.046-0.026)/0.046

                        = 0.43

                        =43% error

Conclusion: The conclusion from this lab is that the radius of a satellite’s orbit is directly related to its period and that the centripetal force is inversely related to the period of a satellite’s orbit. My aha moment was when I plotted the date we collected and saw more clearly the relationship between the two variables. I learned that the escape velocity of a satellite with a circular orbit is ≥8km/s and <11.2 m/s and that the escape velocity of a satellite with an ellipse orbit is ≥11.2 m/s. Finally, I learned that centripetal force is the force directed toward the center of a body’s orbit and centrifugal force dragging a body away from the center of rotation and is equal and opposite to the centripetal force.

Satellite Motion Lab

Problem: This lab had two purposes: 1) to determine whether or not there is a relationship between the radius and period of a satellite’s orbit and if so, what that relationship is, and 2) to determine whether or not there is a relationship between the centripetal force and period of a satellite’s orbit and if so, what that relationship is.

Hypothesis: Prior to the execution of this experiment I did some brainstorming on what I already know about satellites. I knew that gravity keeps a satellite in motion and I knew that something becomes a satellite by being launched out into space at a high enough acceleration. I did not know the difference between a circular satellite and an elliptical satellite or the difference between centripetal and centrifugal force and finally, I did not know what role these forces play in satellite motion. My hypothesis for the outcome of this lab was that there is a relationship between the two sets of variables and constants but I did not really have an idea on what that relationship is.

Procedure: For this lab we did two separate experiments. For the first we kept the centripetal force constant and we changed the radius of the orbit five different times. For each new radius we tested the period three separate times and found an average of those three trials. For the second portion of the experiment we kept the radius of the orbit constant and changed the centripetal force five different times. For each new centripetal force we tested the period three separate times and found the average of those three trials.

Data:

	Period (s)
Radius (m)	1	2	3	Average
0.20	0.28	0.26	0.31	0.28
0.30	0.36	0.32	0.32	0.33
0.40	0.43	0.43	0.43	0.43
0.50	0.46	0.46	0.46	0.46
0.60	0.49	0.48	0.51	0.49

Weekly Reflection 10/11-10/15

I found this week to be really interesting. I really have a very basic knowledge of astronomy so I thought learning the difference between comets, asteroids, meteoroids and the two types of planets was really interesting because I've always just kind of lumped the different items and debris in space into one big category. I also had a lot of fun with the satellite lab. I like really straightforward labs like that (hypothesis, procedure, create a table, collect data, conclusion). My aha moment was when you created the comet because it was cool to see it might actually look like. I don't really have any unclear moments from this week, I'm just glad to have a better knowledge of differences between different debris.

Weekly Reflection 10/4-10/8

I found the information this week to be pretty straight-forward. The information on waves was pretty much review for me but different laws (Wein’s and Stefan’s) were new information but easy to grasp. The majority of my time was spent finishing up the homework for this unit which I found to be fairly simple. I also found the lab to be interesting and easy. Finally, I felt pretty good about the test but I know I could’ve done better if I had spent more time preparing for it.

Telescope Research: Fermi Gamma-Ray Space Telescope

     The Fermi Gamma-ray Space Telescope was launched on June 11, 2008. It is a high-energy gamma-ray telescope that emits gamma-rays only in extreme conditions and it covers about 20% of the sky at all times, scanning continuously and covering the entire sky every three hours. The high-energy gamma-rays that Fermi emits cannot be refracted by a normal lens or mirror and instead are detected with technology used in high-energy particle accelerators. The emitted gamma-rays pass through a plastic anticoincidence detector and charged cosmic rays cause a flash of light which allows Fermi to detect the gamma-rays.
     From this point the detected gamma-rays then continue until they come in contact with an atom and produce an electron and a positron. The charged particles then create ions in thin silicon strip detectors which alternate in the X and Y directions allowing the particles’ progress to be tracked. Lastly, a cesium iodide calorimeter stops the particles and measures the energy deposited which allows physicists to estimate the energy and direction of the gamma-ray.
     Fermi was designed with three main missions in mind. The first was to explore environment out in the universe that are very different from Earth's environment. Secondly, it seeks to explore Dark Matter for other laws of physics and explain how black holes are able to accelerate objects to a speed almost as fast as the speed of light. And Lastly, Fermi was designed to understand gamma-ray bursts along with general longstanding questions. As far as discoveries to, Fermi was the first to detect gamma-rays from a nova which proved wrong the theory that novae are not able to emit radiation so high.