The year is 2025. Imagine you are a Martian, minding your own business, when out of the blue a spaceship lands nearby and out pop four pale earthlings, who announce they are colonizing your planet. They are the first wave of settlers sent by Mars One, a Netherlands-based non-profit, which last week whittled 200,000 applicants to 100 finalists. Most are in their 20s and 30s. They seem educated and motivated, adventurous and idealistic, a little nuts. Eventually 24 winners will make up six crews that will blast off every two years, beginning in 2024. The trip should take seven months. There's no way back, so they’re going for good. An MIT study estimates they will survive for 68 days. This isn’t the first time small groups of humans have set out on months-long, one-way trips. The Mayflower carried 102 Pilgrims; 100 people settled at Jamestown. If history is any guide, the greenskins would be wise not to offer to help the immigrants – because life on Mars will never be the same once the pioneers set about planting gardens and blowtorching ice in the name of “expanding ourselves as a species.”

We have blown through this planet amazingly quickly; so it’s on to the next frontier. I won’t be going. I’m too old, and besides, I’d like to see what I can still do here – for, as Oliver Sacks wrote yesterday: “I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and adventure.”