Always the source of fascination among schoolchildren, NASA's latest space mission will be watched even more closely by students from 13 schools scattered across the northern United States.

Those schools will be a part of the THEMIS (Time History of Events and Macroscale Interactions During Substorms), launched in February 2007 aims to explore the causes of substorms, the violent magnetic storms that happen when charged particles emitted from the sun hit Earth's magnetic field.

Substorms cause the "dancing" aurora borealis -- also called the northern lights -- that can be seen throughout the northern United States and Canada, but they also can wreak havoc with communications and other satellites and could endanger astronauts in space.

To study the storms, NASA has launched five satellites that will orbit the Earth at distances ranging from about 40,000 miles to about 120,000 miles (one-sixth to one-half the distance to the moon). The satellites line up once every four days and measure changes in the magnetic field at these different distances, in order to pinpoint where substorms start. NASA scientists said they expect the satellites to be able to observe about 30 substorms during the two-year mission.

But the satellite measurements alone can't tell scientists all they need to know about substorms, explained project scientist Stephen Mende, because each satellite only measures the magnetic field at one point in space.

"The satellites are very good at measuring the local fluxes of magnetic fields in space, but they're very poor at mapping things. It's like trying to measure the weather when you're on a train ... you don't know whether it's a big storm, because you're only at one point," he said.

So a series of ground-based observatories in the United States and Canada will complement the satellites' measurements. The observatories contain fish-eye cameras that take pictures of the aurora borealis, as well as magnetometers that record data about the magnetic field on Earth. This provides useful information, because energy released during the substorms travels back to Earth along magnetic field lines and causes the aurora to light up and dance -- or contract and expand -- where the field lines hit Earth's atmosphere. So scientists can use the location of the dancing auroras to trace back along the field lines to the point in space where the storm took place.

"In a way we can use the aurora as a television screen or map of the magnetospheric occurrence," said Mende, who is in charge of the ground-based observatories.

It's these observatories that NASA has placed, in some instances, on the grounds of rural schools in Alaska, Minnesota, Wisconsin and other northern states. Eleven schools house magnetometers alone, while two others, both in Alaska, house both magnetometers and fisheye cameras. Eighteen other full observatories -- not on school grounds -- are located across Canada.

"You need a whole network of magnetometers, because [the substorm and aurora] might happen over someone else's site," said auroral scientist and THEMIS education specialist Laura Peticolas. Peticolas said that education and public outreach is a standard part of each NASA mission -- but that THEMIS is taking that outreach a step further.

"Whenever you write a proposal for NASA, along with it comes an education component. But this time we decided 'wouldn't it be great to get teachers and students directly involved with the data, so they could see what science is all about' -- that it's not just a bunch of facts," she said.

One teacher at each of the THEMIS schools is responsible for overseeing the magnetometer, said Peticolas. "If it stops sending data to UCLA or to us, then it's up to the teacher to contact someone to find out what happened," she explained.

Mainly, however, the teachers' responsibilities are educational rather than custodial -- to use the THEMIS science as much as possible in the classroom. The teachers are teaching basic lessons about magnetism, Peticolas explains. But they are also working with real data from the magnetometer, doing lessons such as comparing the magnetometer data to their own experiences of the auroral lights.

"If the data is changing a lot, you might have an auroral change," Peticolas said. "A lot of our schools are at high enough latitudes that they can see auroras, so if they've seen a lot of activity on their magnetometer plots, they might go outside that night."

The primary goal of the observatories, however, is scientific rather than educational. That's why the majority of the full observatories -- the ones that include both a camera and a magnetometer -- are not based at schools, according to Mende.

"The primary thing is that we need to put them where there are no streetlights, and far from anything that would disturb the magnetometers, like a power plant," explained Mende. "And we specifically need to locate them so that we have good coverage of the whole sky."

But the school-based magnetometers also are providing data that may become valuable, as well as exposing students to the kind of real scientific research that rarely makes it into the classroom, said THEMIS principal investigator Vassilis Angelopoulos.

"The important thing for me, for us, was to involve them in the scientific research," Angelopoulos says. "Not to do cutting-edge research themselves, that takes years and years, but to expose them to real-life scientists and engineers, and to show that science is more than just facts."

-- By Lea Winerman, Online NewsHour