At a moment when “long term” for most people means worrying about next month’s mortgage payment, two Swiss scientists have published a proposed strategy for a rescue plan for how humankind could save not just itself, but also our entire planet when our sun turns into a Red giant 5 billion years from now. The short-term option (good only for the next 5 giga-years) is to construct a planet-shielding “parasol” at LeGrange Point L1, permanently eclipsing Earth during the Sun’s gaseous expansion.
Of course, as the authors are quick to point out, this strategy is just a short-term fix, as eventually the Sun’s radius will expand a hundred-fold, swallowing Earth within its envelope. Survival beyond 5 G-yrs thus requires something a bit more ambitious. The authors propose shifting the Earth 50 AU into the Kuiper Belt by means of a swing-by dance with other Solar System bodies.
Given that it would be a long (10 megayear), dark trip to the Kuiper Belt, Earth would also need a temporary artificial sun during the journey, and a long-term artificial sun upon arrival in the Kuiper Belt. The authors propose to provide temporary lighting enroute with a ring of fusion power stations arrayed necklace-like in a ring the size of the moon’s orbit.
We would need something a bit more permanent upon arrival in the Kuiper Belt and thus the authors propose to combine a G5-class star much like our sun with a body a third the Sun’s size to create a new and improved Sol 2.0 having a lifetime approximately an order of magnitude greater than our current local star. Now, that is long-term thinking!
For the full article, see:
M. Taube, W. Seifritz (Submitted on 25 Nov 2008) http://arxiv.org/abs/0811.4052v1