According to NASA, Jack Scudder, who is a researcher at the University of Iowa, has found "hidden portals on Earth's magnetic field [that] open and close dozens of times each day". Some of them are open for long periods of time.
Scudder says that these portals "create an uninterrupted path leading from our own planet to the sun's atmosphere" 150 million kilometres away.
Called X-points, or electron diffusion regions, they are located a few tens of thousands of kilometres from Earth. The portals are created through a process of magnetic reconnection in which lines of magnetic force from both celestial bodies mingle and criss-cross through space. The criss-crossing creates these x-points.
The portals are "invisible, unstable and elusive", opening and closing without any warning. When they open, however, they are capable of transporting energetic particles at high speed from the sun's atmosphere to Earth's atmosphere, causing geomagnetic storms.
There's a way to locate them, and Scudder has found it. He uses data by NASA's THEMIS spacecraft and the ESA's Cluster probes, following crucial clues found in the data from NASA's Polar spacecraft, which studied Earth's magnetosphere in the late 1990s:
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.
This is what the magnetic portals look lik on the data gathered by NASA's Polar spacecraft.
NASA is getting ready such a spacecraft in its Magnetospheric Multiscale Mission -- four ships will be deployed around Earth and "surround the portals to observe how they work". The spacecraft will launch in 2014. [NASA]