Billionaire Bill Gates has said that he would rather pay for vaccines on Earth than for travelling to Mars. “It’s actually quite expensive to go to Mars. You can buy measles vaccines and save lives for US$1,000 (S$1,330) per life saved,” he told the BBC. Since Mr Gates is not a poor man, financial reasons are not the real basis for his choice: Ethical considerations are. Money can be spent either going to space, the ultimate luxury travel destination, or on lightening the gravitational burden of poverty and suffering right here on Earth. The BBC put its interview with Mr Gates in context by noting that the renowned philanthropist, who has lived much of his life as the richest person in the world, has donated generously to causes that include global health, especially that of children. His interests are divided now between climate change and eradicating malnutrition and disease. For all his wealth, Mr Gates is a very grounded man.

That is not because Mars has no takers. Entrepreneur Elon Musk – founder of SpaceX, maker of launch vehicles and spacecraft – actually wants to colonise it, while another icon of global business, Mr Jeff Bezos, has also joined the profitable race to space. Obviously, the Earth is not the only space in which to make money. Indeed, it might turn out to be a business nightmare should climate change, overpopulation, a nuclear war or some other mass calamity destroy the laws of demand and supply that drive economics. Surely, every business needs a Plan B, and what better such plan can there be than to migrate in advance to fresh inter-planetary pastures? They offer prospects of markets to be created and profits to be made. True, the Outer Space Treaty forbids nations from claiming territory there, but laws can and do change.