Magnetosphere is the region around a planet dominated by the planet’s magnetic field. Other planets in our solar system have magnetospheres, but Earth has the strongest one of all the rocky planets.
Significance: The magnetosphere shields our home planet from solar and cosmic particle radiation, as well as erosion of the atmosphere by the solar wind – the constant flow of charged particles streaming off the sun.
How it is generated? Earth’s magnetosphere is part of a dynamic, interconnected system that responds to solar, planetary, and interstellar conditions.
It is generated by the convective motion of charged, molten iron, far below the surface in Earth’s outer core.
1. Constant bombardment by the solar wind compresses the sun-facing side of our magnetic field.
2. The sun-facing side, or dayside, extends a distance of about six to 10 times the radius of the Earth.
3. The side of the magnetosphere facing away from the sun – the nightside – stretches out into an immense magnetotail, which fluctuates in length and can measure hundreds of Earth radii, far past the moon’s orbit at 60 Earth radii.
Why study magnetosphere?
1. To better understand its role in our space environment. It will unravel the fundamental physics of space, which is dominated by complex electromagnetic interactions unlike what we experience day-to-day on Earth.
2. Better understanding of the science of the magnetosphere helps improve our space weather models.
Key terms:
• The solar wind drags out the night-side magnetosphere to possibly 1000 times Earth’s radius; its exact length is not known. This extension of the magnetosphere is known as the Magnetotail.
• The outer boundary of Earth’s confined geomagnetic field is called the Magnetopause.