Experts may have found new active region in Earth's magnetosphere

Feb 27, 2012 07:31 GMT  ·  By

Using direct satellite observations and supercomputer simulations, experts at the Massachusetts Institute of Technology (MIT) discovered the existence of an active region in Earth's magnetosphere. This region accelerates electrons to incredible speeds, promoting the formation of polar lights.

Auroras – called northern or southern lights – appear when charged, fast-traveling, energetic particles produced during solar flares or coronal mass ejections strike our planet's magnetosphere, and then flow along the lines of Earth's magnetic field.

But previous investigations also determined that charged electrons played a role in the process. What experts could not explain was how these particles formed. The new study shows that they receive their weird properties in a special layer of the magnetosphere.

This active region is about 1,000 times larger than researchers thought possible. What this implies is that electrons have enough room to receive a considerable boost in speed. The study was coordinated by lead author and MIT investigator, Jan Egedal.

Details of the research effort appear in the February 26 issue of the top journal Nature Physics.

“People have been thinking this region is tiny. [Now] we’ve shown it can be very large, and can accelerate many electrons,” Egedal explained in a recently released statement, Space reports.

For this study, the expert and his team used data from multiple spacecraft, including the four-satellite Cluster constellation, which is operated by the European Space Agency (ESA). The datasets were augmented with data from Kraken.

The latter is a 112,000-processor supercomputer belonging to the US Department of Energy (DOE), and operated by experts at the Oak Ridge National Laboratory (ORNL), in Tennessee. In order to track the development of auroras, experts simulated the motions of around 180 billion electrons.

A portion of the magnetosphere called the magnetotail – which spreads out behind Earth because it's constantly being pushed by solar wind – is believed to be responsible for bouncing electrons back and forth, accelerating them to extreme speeds.

What the study determined was that the magnetotail is large enough to allow for particle acceleration. In the past, experts did investigate this idea, but concluded that the magnetospheric layer was too small to produce any meaningful acceleration.