Alien life could take many different forms, but one possibility is captivating scientists: alien “plants”. What would they look like? And how could we find them?
On the Orion arm of the Milky Way galaxy, around 93 million miles (150 million kilometres) from the yellow dwarf star it orbits, is a medium-sized rocky planet. At the edge of a vast southern ocean, are the gently lapping waters of a hot-pink lake. With snow-white, crystalline shores, and more than 38 times the salt concentration of pickled olives, among its sole inhabitants are a kind of obscure life with a striking purple hue. These primitive microorganisms are decidedly alien-like: not quite bacteria, but not exactly like anything else either, they are able to thrive in conditions that seem utterly inhospitable.
This planet is, of course, Earth – and the lake is found on the southern coast of Western Australia. But the purple “halobacteria“, which help to ensure the waters of Lake Hillier remain permanently Barbie-pink are also thought to hold clues to finding a certain kind of life on more distant worlds: alien vegetation!