002: Mars
When I was a teenager, I was captivated by the idea of terraforming Mars. Basically, transforming the inhospitable environment of Mars into an Earth-like oasis in space. However, in adulthood I learned that the dynamo at the heart of Mars was essentially dead. This means that the magnetosphere that we have here on Earth is missing. Without the electromagnetic protection that our planet’s healthy dynamo provides, the Mars rehab project appears impossible.
Initially, I viewed terraforming as basically a scaled-up version of the HGTV home renovation show “Flip or Flop.” Obviously, this is not even remotely close to the actual situation. Without a magnetic field, the solar wind can erode away an atmosphere. However, just because a planet doesn’t have a magnetic field doesn’t mean that solar wind will strip an atmosphere. Venus doesn’t have a magnetic field, and despite experiencing an even stronger solar wind than Earth, it has a very thick atmosphere. Venus can hold on to its atmosphere, because it’s dense and tightly bound to the planet. Mars’ gravity is too weak to compress its atmosphere like that. As such its atmosphere is too thin to prevent solar wind erosion.
It was once working. Scientists believe that Mars was a vibrant planet with liquid water primed for life. When the planet’s core cooled, the magnetic field crapped out. As such, it’s unlikely that the pressure can be increased to a level whereby the air can support human and plant life. The surface radiation levels are prohibitive to surface farming. Without scalable agriculture a large functioning community on Mars will be impossible. Also, there is no protection from solar events. Random solar flares can damage technology and kill people on the surface.
A small-scale solution might be to provide local protection through some kind of active shield for a Mars colony, and limiting terraforming to a habitat dome. This is well short of the original idea of a complete global rehab. I believe there might be a way to hack the Mars problem.
Japanese scientists at the National Institute for Fusion Science of Japan believe that an artificial geomagnetic field generation can be achieved with a superconductive ring network. The model that they used was designed based on Earth. This technique was created as a possible solution to the sudden loss of the Earth’s magnetosphere in the context of a polarity reversal.¹ Given that Mars has half the diameter of Earth and that superconductivity can be achieved easier with the natural cold of space, it’s my opinion that applying this solution to Mars could best be done from orbit.
If you now introduce greenhouse gases, you can heat and thicken up the atmosphere. The radiation will become Earth-like. In a century, or two, or three, there will be open-air farming and walks by the lake wearing a t-shirt, jeans, and flip-flops. Terraforming is a cool concept, because the byproduct is not just an excellent tourist destination, but a backup Earth.
Reference:
Motojima, Osamu & Yanagi, Nagato. (2008). Feasibility of Artificial Geomagnetic Field Generation by a Superconducting Ring Network. National Institute for Fusion Science (NIFS) of Japan. Retrieved from http://www.nifs.ac.jp/report/NIFS-886.pdf.