Earth's Magnetosphere

[rangerrebew]

Earth's Magnetosphere

Enveloping our planet and protecting us from the fury of the Sun is a giant bubble of magnetism called the magnetosphere. It deflects most of the solar material sweeping towards us from our star at 1 million miles per hour or more. Without the magnetosphere, the relentless action of these solar particles could strip the Earth of its protective layers, which shield us from the Sun’s ultraviolet radiation. It’s clear that this magnetic bubble was key to helping Earth develop into a habitable planet.

Compare Earth to Mars – a planet that lost its magnetosphere about 4.2 billion years ago. The Solar wind is thought to have stripped away most of Mars’ atmosphere, possibly after the red planet’s magnetic field dissipated. This has left Mars as the stark, barren world we see today through the ‘eyes’ of NASA orbiters and rovers. By contrast, Earth’s magnetosphere seems to have kept our atmosphere protected.

https://science.nasa.gov/science-news/news-articles/earths-magnetosphere

[Joe Wooten]

If Mars had higher gravity, I bet it would have kept more atmosphere. Look at Venus, virtually no magnetic field, but it still has a very thick atmosphere despite being 4 times close to the sun.