Mystery of High-latitude Auroras' Origin in Space Revealed

by Kalyani Thivakaran on December 21, 2014 at 5:10 PM

 Mystery of High-latitude Auroras' Origin in Space Revealed
ESA's Cluster and NASA's Image satellites have worked together to explain the most visible manifestation of the Sun's effect on Earth, a particular type of very high-latitude aurora.

Although separated by some 150 million kilometers, the Sun and Earth are connected by the solar wind. This stream of plasma, electrically charged atomic particles, is launched by the Sun and travels across the solar system, carrying its own magnetic field with it.

Depending on how this 'interplanetary magnetic field' is aligned with Earth's magnetic field when it arrives, there can be various results. At the point where the two fields meet, Earth's magnetic field points north. If the interplanetary field is pointing south, then 'magnetic reconnection' can occur, where magnetic field lines pointing in opposite directions spontaneously break and reconnect with other nearby field lines which opens the door to solar wind plasma entering the magnetosphere or Earth's magnetic 'bubble.'

The ultimate result can be colorful displays in the night sky known as the Northern or Southern Lights, produced when the particles are channeled along Earth's magnetic field lines and strike atoms high in the atmosphere. The interaction with oxygen atoms results in a green or more rarely red glow in the night sky, while nitrogen atoms yield blue and purple colors.

But when the interplanetary magnetic field points northward, auroras can occur at even higher latitudes and one type is known as a 'theta aurora' because seen from above it looks like the Greek letter theta an oval with a line crossing through the center.

ead author Robert Fear from University of Southampton said that the possibilities have been debated since the first satellite observations of the phenomenon were made in the 1980s, but one idea is that the process of magnetic reconnection on the night side of Earth causes a build-up of 'trapped' hot plasma in the higher latitude lobes.

Fear added that they found that the energetic plasma signatures occur on high-latitude magnetic field lines that have been 'closed' by the process of magnetic reconnection, which then causes the plasma to become relatively hot.

Fear continued that because the field lines are closed, the observations are incompatible with direct entry from the solar wind and by testing this and other predictions about the behavior of the theta aurora, our observations provide strong evidence that the plasma trapping mechanism is responsible for the theta aurora.

The paper will be reported in Science.

Source: ANI

News A-Z
News Category
What's New on Medindia
'Hybrid Immunity' may Help Elude COVID-19 Pandemic
Stroop Effect
Plant-Based Diet may Reduce the Risk of COVID-19
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

Recommended Reading
Mysterious Mars: A Water Body Says NASA
NASA's Curiosity Rover traveled 5.5 miles and reached the base of central peak inside Gale Crater, ....
Former NASA Associate Claims to Have Seen Two Astronauts Walking on Mars
A former NASA employee has claimed that, during her time at the space agency years ago, she saw two ...
'Revolutionary Shapeshifting' Aircraft Wings Tested Successfully by NASA
NASA has recently successfully tested revolutionary shape changing aircraft flap for the first ......
Automated Cockpits Affect Pilots' Critical Thinking Skills: Study
Automated cockpits affect pilots' critical thinking skills, reveals a new research....

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use