Nature is indeed the greatest artist, which has its own unique way of spreading colours to inspire human imagination. The polar lights otherwise known as the Aurora is regarded as one of the most attractive light display shown by our little earth. The molten lava and dense core cause convection currents which is responsible for geomagnetism ( the phenomenon behind the magnetic field exhibited by the earth). This is an internally driven phenomenon. The winds reaching us from the sun cause disturbances in the magnetosphere leading to a spectacular exhibition of magical colours concentrating on the polar regions that come and dances in the sky leaving the epiphany of light and nature in our minds and soul.
Recently the MAVEN (Mars Atmosphere and Volatile Evolution mission) by NASA (The National Aeronautics and Space Administration) had given us data regarding Martian aurora which is exhibited by our little neighbour, the MARS. It was in November 2013 that the MAVEN mission was initiated to explore the mysteries of our fellow mate. Scientists were using MAVEN data to determine the role that loss of volatiles from the Mars atmosphere to space has played through time, giving insight into the history of Mars’ atmosphere and climate, liquid water, and planetary habitability. Maven had been mapping the electric currents around mars. According to the experimental physicist Dr.Robin Ramstad of the University of Colorado, Boulder “These currents play a fundamental role in the atmospheric loss that transformed Mars from a world that could have supported life into an inhospitable desert,”.
Basically our little red planet is not magnetized, but when the solar wind containing ions blows constantly, these give rise to induced currents in the ionosphere of the planet and due to piling up an induced magnetic layer is formed covering the planet, when further wind smashes these currents, they flow to both the sides of the sphere and drape around from the sunlit region to the dark side whereas solar x-rays and ultraviolet radiation constantly ionize some of the upper atmospheres on Mars, turning it into a combination of electrons and electrically charged ions that can conduct electricity.
Ramstad says “Mars’ atmosphere behaves a bit like a metal sphere closing an electric circuit, The currents flow in the upper atmosphere, with the strongest current layers persisting at 120-200 kilometres (about 75-125 miles) above the planet’s surface.” previously there were hints about these layers but MAVEN and the previous missions were not able to complete the links.
The currents can’t be detected directly but the fluctuations in the fields could be detected by the sensitive magnetometer in MAVEN, and the team used the data from it and averaged it out in three dimensions and calculated the currents directly from their distortions of the magnetic field structure.
“With a single elegant operation, the strength and paths of the currents pop out of this map of the magnetic field,” Ramstad said.
Solar-wind-driven atmospheric loss has been active for billions of years and contributed to the transformation of Mars from a warm and wet planet that could have harboured life into a global cold desert. MAVEN is striving to find how this process works and estimate the amount of the planet’s atmosphere that has been lost.
This mission could partly unravel the stories behind the red planet and leave us room for more exciting mysteries.
References: NASA, nature astronomy
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