One of the futuristic dreams of space visionaries is the idea of terraforming #Mars, restoring it to the green, wet world with an atmosphere that many scientists believe that it possessed billions of years ago. A number of terraforming schemes exist, mostly having to do with restoring Mars’ atmosphere and thus producing a greenhouse effect that would raise the temperature on the planet and release trapped water at the poles. Now, according to Popular Mechanics, Jim Green, NASA's Planetary Science Division Director, presented a fresh idea for turning Mars into a new Earth at the Planetary Science Vision 2050 Workshop.
The reason Mars is a frigid, arid world is that the planet lacks a magnetosphere to shield it from solar radiation as the Earth does. Hence, the constant bombardment of solar particles stripped away most of Mars’ atmosphere, turning it from a green to a #Red Planet.
Green’s idea is to not so much provide Mars with a magnetosphere but a #Magnetic Shield. A large dipole would be deployed at the Mars Sun L1 point, where the gravities of the two bodies tend to cancel out. The dipole would be powerful enough to generate a magnetic field to shield Mars from solar wind and radiation.
Most scenarios for Mars terraforming suggest that the process would take centuries. Green’s scheme would build up a Martian atmosphere from melted carbon dioxide to the point that Mars would have half the atmospheric pressure as Earth. Water would melt and fill the ancient valleys and basins that were once rivers and seas. One seventh of the volume of water that used to be on the Martian surface would be restored. The process would take place over a span of years and not centuries. Then genetically tailored plants and animals would be introduced to give Mars an ecological system for the first time in billions of years.
Living in an environment with half the atmospheric pressure of Earth at sea level would be like living on a high mountain. Very likely Mars colonists would carry around oxygen tanks when they go outside, at least until some way was found to augment and maintain a denser atmosphere. But Mars would become a far more attractive new home for humanity than the version that exists currently.