Earth’s proper distance from the Sun, thick water-rich atmosphere, availability of abundant amount of oxygen and liquid surface water are the properties that make Earth, a life sustainable planet. These are what we have conned so far. But all these properties would have been destroyed or wiped out if the Earth have not had its magnetic shielding.
Scientists have recently discovered that many exoplanets that reside within the Goldilocks Zone, an area in which a planet is at the suitable distance from a star (like Earth), may be missing their magnetic shielding and as a result of it, they may be susceptible to Sun’s damaging radiations. Venus and March do not have magnetic shielding Mars atmosphere are thought to have been eliminated by stellar winds after its magnetic field depleted and Venus are thought to have oceans once which got dried up as the greenhouse effect took hold.
“Water can get blasted away by stellar winds unless the planet has a strong magnetic field, Mars and Venus do not have magnetic fields, and it is thought that stellar winds stripped away the bulk of Mars’s atmosphere, while Venus’s was left with mostly carbon dioxide, making it toxic” says Jorge Zuluaga from the University of Antioquia in Colombia.
The magnetic field of the Earth extends from the inner core to where it meets solar wind, the continuous flow of charged particles from the sun that permeates the solar system. This magnetic field staves off most of these particles( Radiations and Winds) from entering the Earth’s atmosphere which otherwise would blast away our ozone layer.
Read more at ESA.