Science Lab HW-Sunspots
tarkgaHow did Galileo go blind?
Or, It’s the Data, Stupid!
Description:
Four hundred years ago there was a man who wanted to understand the universe and who found that what humans knew was limited. The brightest minds had come up with ideas of how things worked that simply contradicted what he knew to be true. As a result, he began to do things that no one expected. First, he dropped objects from the top of the tower of Pisa (not leaning yet). Then, he took a small telescope that he made based on a design he found in a publication by a Dutch optician and he pointed it to the heavens. He looked at the Sun, the Moon, Venus, Jupiter, Saturn, and the Milky Way. What he observed challenged everything the smartest people around were telling him must be true. Nonetheless, he carefully made observations and recorded his data. He developed models based on these data that were rejected because they were not consistent with the dogma of the time. Today we know that Galileo was correct and that his observations marked the beginning of experimental science.
This exercise explores modern observations of the Sun, using data (observations) to explain observed phenomena (such as sunspots, coronal mass ejections, and solar flares).
Introduction:
A model or a description without data to support it is as good as a fairy tale in science. Theories in science rely on strong support from many different data sources. Galileo’s contribution to science was first and foremost that he supported everything with actual data. He was one of the first in a long time to do this. To understand the Sun (the object Galileo observed which caused his blindness), we must gather together all the observations of this object and try to understand them.
This exercise will incorporate data from many sources on the internet to try to understand phenomena of solar activity – namely, sunspots, flares, and coronal mass ejections. Our working hypothesis is that sunspots, flares and coronal mass ejections are caused by distortions in the Sun’s magnetic field. We will now look at what data we can find and see if the data support this hypothesis.
1. Go to the following URL and look for data that could support or falsify the above hypothesis statement. http://sohowww.nascom.nasa.gov/home.html Click on the link titled “The Sun Now”. You will need to locate data that show sunspots (continuum images), flares (EIT 171, 195 or 284 images), coronal mass ejections (LASCO C2 and C3 images), as well as magnetograms.
2. Identify the observed features and compare their locations. If there are no sunspots, verify that there are also no flares or coronal mass ejections or magnetic disturbances, then look for data on a day when there were features to observe. Note that on the magnetogram dark and light spots indicate areas of anomalously strong magnetic polarity.
OPTIONAL Part 3: Using the images available identify and describe the following features: sunspot, prominence, flare. Answer the following questions: In which images are sunspots most easily seen? Why? Why are sunspots dark?
4. Do the data you’ve found support the hypothesis that these phenomena are all related to magnetic anomalies? In every case where there is a sunspot, is there a magnetic anomaly? In every case where there is sunspot, is there a flare? Are coronal mass ejections only associated with sunspots?
5. Describe how the Sun’s magnetic field causes these phenomena you observe. The accepted scientific models of solar activity show the Sun’s magnetic field, which is embedded in the material that makes up the Sun, winding up to cause the observed magnetic anomalies. Use the SOHO Movie Theatre to create a movie and observe the motion of sunspots on the Sun. (If this is a relatively inactive time, use October 15, 2003 through November 15, 2003.)
OPTIONAL Part 6: Write up your results in a report. Describe the data you used in this experiment and include any images you can (be sure to name the source for each image). Explain your method of analysis and your conclusions.
OPTIONAL Extension Part 7: Explore the NASA websites to learn more about how the magnetic field causes sunspots, flares and coronal mass ejections. Learn how these phenomena effect Earth (i.e., aurora borealis, radio static). Include this information in your final paper. Another good website is www.spaceweather.com where some of this information can be found by following one of the many links on the left-hand side or bottom of the web page.