Researchers examining data from a NASA satellite have discovered “portals” in the Earth’s magnetic field.
According to a report from Phys.org, physicist Jack Scudder of the University of Iowa has found what he terms “X-points” in the Earth’s magnetosphere, the magnetic field generated by the planet itself. The magnetosphere protects our planet from harmful radiation, in addition to being the cause of everyday effects like causing compass needles to point north.
Dr. Scudder explains that the X-points are “places where the magnetic field of Earth connects to the magnetic field of the Sun, creating an uninterrupted path leading from our own planet to the sun’s atmosphere 93 million miles away.” Instead of being deflected, these openings in the atmosphere allow solar particles to be conducted into the Earth’s upper atmosphere. These charged particles can be responsible for geomagnetic storms and auroral displays.
According to an earlier report from NASA, these portals have only be recently discovered. “Ten years ago I was pretty sure they didn’t exist, but now the evidence is incontrovertible,” Dr. David Sibeck of the Goddard Spaceflight Center told NASA Science News in 2008.
These X-points or portals have only been glimpsed by NASA spacecraft before, and the space agency plans a future mission to study them in more detail. However, they are elusive and temporary structures, which form and vanish in unpredictable ways. A major problem has been simply finding the portals, because of the lack of any guides to their appearance.
Now, Dr. Scudder reports that he has found a way to detect the portals, and he has done so by examining decade-old data from NASA’s Polar spacecraft, which was launched in 1996. “Using Polar data, we have found five simple combinations of magnetic field and energetic particle measurements that tell us when we’ve come across an X-point or an electron diffusion region. A single spacecraft, properly instrumented, can make these measurements,” explains Dr. Scudder. This new approach shortens the time necessary for future studies of the X-points; mission planners had previously counted on spending a year or more just learning to find them. Now, they should be able to find and being studying them immediately.
The Polar spacecraft was decommissioned in 2008, although it remains in orbit.
The findings are reported in the journal Physical Review Letters. Dr. Scudder’s work is funded by NASA. A video from NASA discussing this story is available here.