And yet, roughly 40,000 people make the trip to Everest Base Camp each year -- another desolate and inhospitable place with no tangible economy. An economist might say this is done for 'tourism', but I prefer Mallory's famous insight that people go 'because it's there'.

Ever since we came down from the trees, humans have been setting out on reckless and suicidal journeys for which there is no hope of return. Humanity spread over nearly the entire planet and found its way to countless isolated pacific islands before recorded history even began.

When the price and the science finally line up, there will be no shortage of wealthy old kooks happy to pony up the funds, accept the risk, and set off for the solar system's most exotic retirement.