Grad Student, Philip Fernandes, Studies Northern Lights
Physics and astronomy graduate student Philip Fernandes builds instruments that are shot into space aboard a rocket aimed at the Aurora Borealis (Northern Lights).
The research or “sounding” rockets are launched from sites in Alaska and Norway into the ionosphere that extends between 46-621 miles above the earth during periods of heightened solar activity when the Aurora Borealis is most prominent. The ion measuring instrument that Fernandes helped build is mounted on an 8-inch boom that is deployed when the rocket approaches the aurora. At that point the instrument turns on and begins recording and transmitting data to NASA telemetry receiving sites on the ground. The space agency then compiles the data and provides it to Fernandes and other researchers who have instruments aboard the rocket.
Fernandes’ instrument includes a “top-hat,” a 2-inch aluminum disk that is set off from the rest of the device by a small gap that allows ions to pass through. An electric field is used to guide the ions into a detector where their energy—temperature and density—is measured. The data collected is analyzed with a goal of better understanding this aspect of space weather.
Most auroras occur in a zone within 10 to 15 degrees of latitude of the geomagnetic poles. During periods of increased solar activity the auroral zone can be stretched into temperate latitudes, allowing the Northern Lights to be seen on rare occasions as far south as Colorado and Nebraska.
These colorful events have been the source of curiosity for thousands of years with early references in the Old Testament, Chinese literature, and the writings of Galileo, Hubble, and other respected scientists. Early theories attributed the shimmering in the sky to burning clouds or reflections from ice crystals.
Fernandes grew up in Colorado, and he was a fan of Star Trek as a youngster. He was drawn to high school physics because he liked to solve problems and to get precise answers. After graduation, he enlisted in the Marine Corps Reserve and served five years as a military policeman at bases in California, Arizona, and Massachusetts. He received an associate’s degree from Mesa College in San Diego, and at the suggestion of a Marine Corps buddy, enrolled at the University of New Hampshire where he majored in physics with a concentration in astronomy. This allowed him to do research in space science, which he would later pursue as a graduate student at Dartmouth under the supervision of Professor Kristina Lynch.
With Lynch and scientists from other university research labs, Fernandes has traveled to Alaska and Norway to witness the launch of the sounding rockets that carry their research instruments. He remembers flying into Fairbanks, Alaska, for a launch from the University of Alaska’s Poker Flat Research Range located 30 miles north of the city. While conditions may have indicated heightened auroral activity, the outside temperature registered an uncomfortable 30 degrees below zero. “I thought it was cold in New Hampshire, but nothing like that,” Fernandes remembers.
While fascinated with the Aurora Borealis and the phenomenon that creates it, Fernandes is especially interested in space weather more generally and the hazards it can cause for satellites and the instruments they carry. “It all begins at the sun, where this mass of hot plasma spews out a steady stream of ions and electrons,” Fernandes explains. This “solar wind” of charged plasma courses toward our planet at about one million miles per hour. When the solar wind particles reach the Earth, they can become trapped in the Earth’s magnetic field and channeled toward the magnetic poles. As they approach the upper atmosphere, they collide with other atoms and molecules, which become energized or “excited.” When the energy added by these collisions dissipates—discharges—the atoms change their energy state and give off light that we recognize as the Northern Lights.
Fernandes says that in addition to the spectacular light show, the collision of charged particles can also cause sudden and damaging electrical surges on communications satellites and global positioning systems (GPS). His hope is that a better understanding of the space weather in which auroras occur will lead to improved satellite design. When he completes his degree, Fernandes hopes to continue to work in space physics at a national laboratory or technology center.
by Michael Beahan
photos courtesy of Philip Fernandes