Space probes and planetary rovers are humanity’s agents of extreme tourism, taking pictures of the grandest vistas of the solar system and beaming them back to earth for our delectation. And, just like seasoned earthbound tourists, who would not dream of leaving home without a good selfie stick, they are equipped with their own these days. Two weeks ago, Nasa’s Curiosity rover snapped a dramatic 360-degree panoramic selfie of itself on the Vera Rubin ridge, which it has been exploring for a year. And now, the Maven mission has celebrated four years in orbit around the Red Planet by snapping a selfie using its 12-metre boom.
It’s totally geeky, a composite picture in the ultraviolet band, normally invisible to human eyes. Spiders and some insects can see in ultraviolet, and many plain white flowers that are beneath the notice of gardeners and decorators burn like fireworks in the ultraviolet band, impressing pollinators no end. It is believed that many birds, cattle, reindeer, dogs, cats and bats can see ultraviolet pulsing on power lines, which is why they keep away from them while humans are unaffected. So it’s kind of ironic that the Maven has shot an ultraviolet selfie for human consumption.
But before taking time off to carry on like a geeky space tourist, Maven performed the remote sensing component of its job card. It has established that solar storms had stripped the atmosphere on Mars, that this was the driver of climate change, that most of the planet’s carbon dioxide is lost to space, and that terraforming the planet would be far more difficult than anticipated. That’s a lot of groundbreaking work for one orbiter to do. Maven has done enough to deserve a quick holiday, and snap itself a nice selfie for the folks back home.