Next summer, scientists from Massachusetts Institute of Technology will launch an uncrewed spacecraft to explore our nearest planetary neighbour — not the one you’re thinking of, though. “Mars gets all the attention,” laments Sara Seager, the Toronto native who is leading the project, “and Venus gets ignored.” But that may soon change. Back in 2020, Seager and her colleagues published observations from two powerful telescopes suggesting, somewhere in the clouds of Venus’s atmosphere, the apparent presence of phosphine — a molecule that, on Earth, is associated with living organisms.

Venus is a barren hellscape at ground level, with intense atmospheric pressure and temperatures hot enough to melt lead. Up in the clouds, however, the temperature and pressure are more Earth-like. In the 1960s, astronomer Carl Sagan suggested those clouds might sustain life. The catch: the clouds are made of sulphuric acid. After the phosphine observation, Seager ran a series of experiments showing that certain amino acids and DNA components — building blocks of life — can stay intact in sulphuric acid.

Next year’s launch is part of Seager’s Morning Star Missions, an ambitious multi-part plan to see whether these clues add up to extra-terrestrial life. The spacecraft will drop a small probe that will search for the presence of anything other than sulphuric acid during a five-minute plunge through the clouds. “We send an ultraviolet laser out into the clouds, and if we see it light up — fluoresce — it’s a good sign because it likely means there’s organic molecules in the cloud particles,” Seager explains.

Assuming there are molecules there, the next step is to get a positive ID. The follow-up mission, slated for 2031, will deploy a balloon that stays aloft for a full week and scatter 30 microprobes designed to spin like falling maple seeds as they gather atmospheric data. The balloon fabric is “absolutely top secret,” says inventor Maxim de Jong of Chilliwack, B.C.-based Thin Red Line Aerospace. It will have to float in clouds of sulphuric acid and resist the extreme heat near the bottom of the cloud layer while still being light enough to launch into space. That’s a big ask, and it’s just one of the challenges facing Seager’s team. But as de Jong says, “life is too short to work on something that doesn’t challenge you to the absolute fullest.”