Martian Atmosphere

According to a computer simulation study published in the Monthly Notices of the Royal Astronomical Society, solar winds may have led to Mars losing its atmosphere, which confirms the long held belief that planets need a protective magnetic field to block such harmful radiations in order to sustain life.

- Factors like the existence of a moderately warm, moist atmosphere and liquid water determine whether a planet can host life.
- According to the scientists, magnetic fields enveloping planets can act like a protective umbrella, shielding the atmosphere from the super-fast plasma winds of the Sun.
- On the Earth, a geo-dynamo mechanism generates the planet’s protective magnetosphere — an invisible shield that stops the solar wind from eroding away our atmosphere.

The magnetosphere is the region of space surrounding Earth where the dominant magnetic field is the magnetic field of Earth, rather than the magnetic field of interplanetary space. The magnetosphere is formed by the interaction of the solar wind with Earth’s magnetic field.

- In the study, the scientists simulated two scenarios of the Red Planet — one considering a young Mars with its magnetosphere intact, and the other with the planet without this force field.
- The simulations revealed that in the young Mars, the magnetosphere may have acted as a shield stopping the solar wind from coming too close to the planet’s atmosphere thus protecting it.

The solar wind is a stream of energized, charged particles, primarily electrons and protons, flowing outward from the Sun (released from the upper atmosphere of the Sun, called the corona), through the solar system at speeds as high as 900 km/s and at a temperature of 1 million degrees (Celsius).

Without an intrinsic magnetosphere, the researchers said the solar wind magnetic field may have first draped around, and slipped past Mars, carrying bits of the planet’s atmosphere away, eventually eroding it completely. The findings confirm the belief that the magnetospheres around planets play a crucial role in determining their ability to sustain life.
Alternatively, planets that lose their magnetic field eventually become inhospitable with loss of their atmosphere.
The researchers believe the study has important implications for the search for habitable exoplanets via initiatives like NASA’s James Webb Space Telescope and ISRO’s ExoWorlds mission(exploration outside the solar system in 2028).

Life on Earth initially developed and continues to be sustained under the protection of this magnetic environment.
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.
The aurora is caused by the interaction between Earth’s magnetic field and charged particles shot out from the sun, dissipating them before they cause damage. In the north, the display is called aurora borealis, or northern lights. In the south, it is called aurora australis, or southern lights.

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