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.
Sarah Bird/Michigan Technological University
Aurora borealis above Keweenaw Bay, near Baraga, Michigan, on Sept. 30, 2012.
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, email@example.com, 906-487-2198
Robert Nemiroff | Newswise Science News
Optical Nanoscope Allows Imaging of Quantum Dots
23.01.2018 | Universität Basel
Two dimensional circuit with magnetic quasi-particles
22.01.2018 | Technische Universität Kaiserslautern
Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.
Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
23.01.2018 | Earth Sciences
23.01.2018 | Life Sciences
23.01.2018 | Materials Sciences