Solar monitors distributed to encourage interest in science
Students at Deer Valley High School in Antioch, Calif., work with Sudden Ionosphere Disturbance (SID) monitors, electronic instruments that provide indirect measurements of the sun’s activity.
BY CHELSEA ANNE YOUNG
How do you convince students at underprivileged schools that science is cool? Give them high-tech tools to study the sun. How do you get their schools' support? Give the devices away for free.
This is exactly what Deborah Scherrer is doing. The education director at the Stanford Solar Center, Scherrer heads a Stanford university project to produce and distribute instruments that monitor the sun's impact on the ionosphere, an electrically charged layer 50 miles above the Earth. She and her cohorts and sponsors hope that these small and easy-to-use tools will encourage underprivileged students here and in developing countries to get excited and get involved in science.
"We have the opportunity to reach students in every country of the world," she said.
The instruments provided by Stanford are electronic monitors called Sudden Ionosphere Disturbance (SID) and Atmospheric Weather Electromagnetic System for Observation Modeling and Education (AWESOME). Both are red metal boxes embossed with a Stanford logo. SID can be held in one hand, and AWESOME is the size of a shoebox. Deborah Scherrer and her husband, Phil Scherrer, a professor (research) of physics at Stanford's Hansen Experimental Physics Laboratory, spent two years modifying an older version of SID to create an instrument designed for use by high school and community college students. The new version costs about $200 to build. The Stanford Department of Electrical Engineering developed AWESOME, a more sensitive monitor, which costs about $3,000 and is meant for use at a research university.
The Stanford project is the primary educational outreach effort of the International Heliophysical Year (IHY), a United Nations initiative that aims to encourage science development throughout the world. IHY will be the focus of a May 29 session of the American Astronomical Society in Honolulu led by Stanford researcher Maria Cristina Rabello-Soares and colleagues from the NASA Goddard Space Flight Center.
"The big push is to get the people in developing nations involved in science, as sort of a jump start," Scherrer said.
"You can be part of a worldwide experiment," Phil Scherrer added.How does it work?
"SID is a lot like an AM radio," explained project member Todd Hoeksema, a senior researcher in the Hansen Lab. The monitor connects to an antenna that captures radio waves transmitted through the air. However, there are some important differences between these solar-tracking monitors and the radio you sing along with in the car. While AM radios receive wavelengths ranging from 1 to 100 meters, SID monitors are tuned to a wavelength of 7.5 miles—a very low frequency (VLF) radio wave that can penetrate deep into the ocean and is used by militaries around the world to communicate with submerged submarines.
VLF waves travel around the world by repeatedly bouncing off the ionosphere and returning to Earth. The SID monitor takes advantage of this property to interpret the state of the ionosphere and the activity of the sun. During the daytime, VLF waves lose power, decreasing their strength, each time they hit the ionosphere. However, during a solar flare, X-rays and gamma rays from the sun change the ionosphere and dramatically increase the VLF signal. "We can tell basically what's going on in the ionosphere by where these waves are bouncing and how big their signal is," Deborah Scherrer said.
In the SID project, high school students build their own large antenna from loops of common magnetic wire and point it toward the nearest VLF transmission station. Electromagnetic waves then induce a current in the antenna. But while ordinary radios translate this current into speech or music, SID uses it to measure the strength of the VLF signal. In fact, the characteristic sound generated by SID is irrelevant to the project, Scherrer explained. "You can hear it," she said. "It's like a whoosh or a hiss. But we don't care what the waves are saying. We just measure the signal strength."
When connected to an ordinary computer, SID provides an indirect measurement of the sun's activity, primarily solar flares. Conveniently, solar flares are routinely photographed by government satellites, and their positions are recorded in an online database. "The kids can say, 'Oh, I got a flare yesterday,'" Scherrer said. "And then they can look it up and see the sunspot that created that flare."
The Stanford Solar Center also maintains a centralized database where high school and community college students can add their data and view those of their peers. "We would like students on either side of the world to collaborate with each other," she said. "That's part of the whole project—to encourage teamwork." In fact, scientists from the University of Utah are using the students' data for their research, she added.
AWESOME monitors are similar to SIDs, except they can interpret signals from more than one transmitter and have increased sensitivity. AWESOME monitors can even sense lightning strikes, which also disrupt the Earth's ionosphereFostering science appreciation
So far, Scherrer and her team have distributed about 100 SID monitors to high schools and community colleges in the United States and 12 other countries, including Ethiopia, Tunisia, Sri Lanka and Bulgaria. Teachers can sign up for the program at the Stanford Solar Center website (http://solar-center.stanford.edu/SID/). Scherrer will then mail them a monitor along with directions and variety of educational materials.
Besides the SID monitor and the antenna, which kids build themselves, the only other required equipment is a computer. "An old, junky computer will work just fine," Scherrer said. "Even if you're in Ethiopia or some very poverty-stricken country, you can produce as much data and give as much to the scientific community as Germany, France, the U.S. or Japan. In fact, sometimes more, because a lot of those countries are in places that don't have monitors."
Having little monitors in the classroom encourages students to take active roles in the project, she said: "You get to hold it, you get to mess with it and plug it in. It's yours. All of a sudden, you've got that buy-in that kids really need."
"What we're hoping is that other people will get bright ideas and will contribute those so the project is just a self-sustaining thing," Hoeksema added.
Based on their work with the SID monitors, students have won awards at science fairs, earned college scholarships and even gone on to careers in science. "The whole point of doing something like this is to get students excited about science," Scherrer said.
NASA, the National Science Foundation and Stanford are jointly funding the program. The first round of funding covered development and distribution of 100 SID monitors, and additional funding from NASA and Stanford will soon allow the team to distribute 100 more. Within the year, the group hopes to have SID monitors operating in all 192 countries. Currently, AWESOME monitors have been placed in about 30 sites across the world.
Chelsea Anne Young is an intern at the Stanford News Service.