The Science Behind Those Eye-Popping Northern Lights

Sarah Bird/Michigan Technological University<br> <br>Aurora borealis above Keweenaw Bay, near Baraga, Michigan, on Sept. 30, 2012.<br>

An aurora borealis (aurora australis in the Southern Hemisphere) is precipitated by explosions on the surface of the sun, sometimes starting as solar flares, said Robert Nemiroff, an astrophysicist at Michigan Technological University and coauthor of NASA’s Astronomy Picture of the Day website.

These flares release a burst of charged particles, or plasma, into the solar system. When they come our way, they whack into the Earth’s magnetosphere, which is made up of its own stream of charged particles. That collision causes particles to break free of the magnetosphere and cascade toward the Earth’s magnetic field lines, usually traveling toward the poles.

“The aurorae happen when these high-energy particles bap into atoms and molecules in the Earth’s atmosphere, typically oxygen,” Nemiroff said. Light is emitted as part of the reaction.

Those particles can also wreak havoc. “The plasma cloud can cause the Earth’s magnetic field to fluctuate,” Nemiroff said. “At worst, that can knock out satellites and even power grids.”

Aurorae can happen anytime, but it’s no surprise they are happening now.

“We are nearing the solar maximum, which is when the sun is at its most active,” he said. Solar maximums come around every 11 years, but no one knows why.

“You can have solar flares and aurorae during the solar minimum, but we get more now because the sun’s magnetic field is tangled up and poking through the surface, releasing plasma,” said Nemiroff.

Robert Nemiroff, nemiroff@mtu.edu, 906-487-2198
Marcia Goodrich, mtunews@mtu.edu, 906-487-2343

Media Contact

Robert Nemiroff Newswise Science News

More Information:

http://www.mtu.edu

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors