Idea of life on Mars is no longer really out of this world
Final frontiers are in meagre supply nowadays. People tweet from the summit of Mount Everest, take pleasure cruises of the Arctic Circle, book luxury tours through the Gobi Desert.
For those with the cash and the inclination, few places in the world are truly off limits. In fact, 'dark tourism' specialists even offer whistle-stop visits to such safety-not-guaranteed locales as Afghanistan's Hindu Kush mountains and militarised Kashmir.
Maybe that is why Mars, in the news this week for a multitude of reasons, continues to exert a tug on humanity's consciousness.