The findings, which are published in Nature, have important implications for our understanding of how Mars evolved. Billions of years ago, the planet may have had a thicker atmosphere that allowed liquid water to flow on the surface.
This thicker atmosphere may have been kept in place by a protective magnetic field, like the one Earth has. However, Mars lacks such a field today. Scientists have wondered whether the loss of this magnetic field led to the red planet losing its atmosphere to space over time and becoming the cold, dry desert it is today.
From residual magnetization in the crust, we think that Mars did once have a magnetic field, possibly from a core structure similar to that of Earth. However, scientists think that the core must have cooled and stopped moving at some point in its history.
Agreed on all counts. Yeah, Mars was never really a good candidate for colonies, despite being technically the most earth-like planet.
Realistically, terraforming Mars would probably be something like a 3000 year project. But to me, that doesn’t mean it’s 3000 years away, it means it will actually never happen. Given the ever increasing pace of technology, I can’t actually see a 3000 year project like that ever completing, because in that time the human race, and our goals would have changed immensely. We’re already successfully editing plant and animal genomes, at some point we will have changed ourselves so much that the goal we aimed for a millennia ago no longer makes sense. We likely won’t need an earth-like planet in the same way.
At any rate, I think space habitats are the way of the future, O’Neil cylinders and the like. Once you make it all the way to space, why trap yourself all the way down another gravity well?