Auroras Move to the Rhythm of Earth's Magnetic Field, NASA THEMIS Observes
Auroras are mystifying lights in the sky. Not a lot about the auroras are known to man yet, but NASA's THEMIS data helped scientists in observing the lights; it was proven that auroras move in sync with the Earth's magnetic field.
These lights are of electromagnetic origin and are highly responsive to solar activity. Further analysis allowed a more detailed observation of the behavior of auroras, especially their rhythm. A study was conducted using NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS); it is tasked to observe the vibrating magnetic field of the planet and its influence to the northern lights. Northern lights "erupt" in the sky due to Earth's changing magnetic environment also known as the magnetosphere.
THEMIS is an in-depth team of five spacecraft dedicated to understanding the processes involved with the auroras. "We've made similar observations before, but only in one place at a time -- on the ground or in space," David Sibeck, THEMIS project scientist at NASA's Goddard Space Flight Center said in a press release. "When you have the measurements in both places, you can relate the two things together," Sibeck added.
Solar winds can cause the magnetosphere to contract inwards, the back end called the magnetotail stretches and snaps back. This is the time when auroras occur when the magnetotail vibrates and moves back and forth.
This study reveals what powered the auroras. "We were delighted to see such a strong match," Evgeny Panov, lead author and researcher at the Space Research Institute of the Austrian Academy of Sciences said in a statement. "These observations reveal the missing link in the conversion of magnetic energy to particle energy that powers the aurora," Panov added.
Scientists arrived at their findings by mapping the aurora's movements or "dance" and its changing brightness over Canada. All-sky cameras were used simultaneously with ground-based magnetic sensors to measure electrical currents during a substorm.
While auroras move in rhythm with the Earth's magnetosphere, the magnetosphere is influenced by solar activities and solar winds from the particles emitted by the Sun. Altogether, most forces in space have a direct and indirect effect on natural occurrences on Earth such as the northern lights.
The knowledge about the northern lights can help scientists understand the environment surrounding the planet. Not only does the magnetic forces affect Earth-borne activities, but radiation and energy from space near the planet can also affect the satellites. Electromagnetics and navigational signals can be influenced. This is important because of man's dependence on GPS systems used in various fields such as weather forecasts and explorations.