Indian scientist-led team first to find evidence of solitary waves in Mars magnetosphere – Times of India



NEW DELHI: In a significant discovery, Indian scientists have reported the first evidence of the presence of solitary waves or electric field fluctuations in the Martian magnetosphere. Despite several global missions to Mars, the presence of solitary waves in the Martian magnetosphere had never been reported by any space agency or institute in the world.
The Navi Mumbai-based Indian Institute of Geomagnetism (IIG), an autonomous institute of the Department of Science and Technology (DST), has identified and reported the solitary waves in the Martian magnetosphere with the help of high-resolution electric field data recorded by a Nasa spacecraft. The study of the solitary waves is crucial as they directly control particle energisation, plasma loss and transport through wave-particle interactions.
Speaking to

TOI

, Prof Bharati Kakad, the author of the research paper and scientist with IIG, said, “We studied electric field data recorded by Langmuir Probe and Waves instrument on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft after Nasa put the data in the public domain. Usually any space agency retains and studies data from its payload for six months and then it has to put such data in the public domain as per a policy.When Nasa put that MAVEN data in public domain, our team of four members, which worked on the research papers, studied the data. After three-month analysis of that MAVEN -captured data and other research, we made the discovery of solitary waves in the Mars magnetosphere. Actually, the find was by chance.”
Prof Bharati Kakad and her husband, Amar Kakad, also a scientist in IIG, co-authored the research papers that were published in the Astrophysical Journal in August last year. “We present an analysis of 450 solitary wave pulses observed by the Langmuir Probe and Waves instrument on the Mars Atmosphere and Volatile Evolution spacecraft during its five passes around Mars on February 9, 2015. The magnitude and duration of these pulses vary between 1 and 25 mVm-1 and 0.2-1.7ms, respectively. The ambient plasma conditions suggest that these pulses are quasi-parallel to the ambient magnetic field and can be considered electrostatic,” the abstract of the published research papers said.
“Our Earth is a giant magnet and its magnetic field protects us from high-speed charged particles that are continuously emitted from the Sun in the form of solar wind. Unlike the Earth, Mars doesn’t have any intrinsic magnetic field. This allows the high-speed solar wind to interact directly with the Mars atmosphere. Even in a weak and thin magnetosphere as that of Mars, one can observe frequent occurrences of solitary waves. But the presence of the solitary waves in the magnetosphere of Mars was never noticed by anybody earlier,” Kakkar told

TOI

.
Solitary waves are the distinct electric field fluctuations (bipolar or monopolar) that follow constant amplitude-phase relations. Their shape and size are less affected during their propagation. As these waves are known to be responsible for the plasma energisation and its transport in the Earth’s magnetosphere, the IIG team is further exploring their role in the particle dynamics in the Martian magnetosphere and whether such waves play any role in the loss of atmospheric ions on the Red planet.





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