Venus is a very hostile place for any kind of life as we know it. The surface is scorchingly hot — far too hot for complex molecules needed to make up life. High above the surface, the atmosphere becomes colder and colder. On Venus there is a sweet spot at 48 per 60 km (30 per 37 miglia) above Venus’ superficie, in the clouds, where the temperature is not too hot, not too cold, but just right for life.
Comunque, the environment is harsh. The atmosphere is, per esempio, 50 times drier than the driest places on Earth. The cloud droplets are made not of liquid water but of concentrated sulfuric acid. The acid environment is billions of times more acidic than the most acidic environments on Earth. Earth-life components including DNA, proteins, and amino acids would be instantly destroyed in sulfuric acid. Any life in the Venusian clouds would have to be made up of building blocks different than Earth life, or be protected inside a shell made up of sulfuric acid-resistant material such as wax, graphite, sulfur, or something else.
People have been speculating about the presence of life in the clouds of Venus for over
50 anni, starting with Carl Sagan
. Scientists are sometimes reluctant to openly admit their interest in such a fringe topic
Yet our team lead Jane Greaves of Cardiff University in the UK purposely decided to search for signs of life on Venus by way of phosphine gas
. She proposed to use the James Clerk Maxwell radio telescope
) on Mauna Kea in Hawaii to observe phosphine at radio wavelengths
. By coincidence
, my team at MIT had also been working on phosphine gas as part of a larger project trying to understand which gases on esopianeti
— planets orbiting stars other than the sun
— might indicate the presence of life. A mutual contact connected us
When I first learned of Jane’s finding I simply didn’t believe it
. ciò nonostante, my MIT team worked with Jane’s team on a proposal to use the more powerful Atacama Large Millimeter Array (ALMA
). When the data came back and was analyzed
, the phosphine signal was even stronger than before
. I was still so shocked
, so astonished
, but we now had to accept that the finding was real
. We diligently pressed on to support our detection
, continuing to work through and rule out chemical processes as the phosphine source
, and double and triple-checking that no other gas could mimic the presence of phosphine gas
Our solar system has a growing number of bodies of interest in the search for life. NASA’s Mars Perseverance rover is on its way to Mars to search for signs of ancient life. Jupiter’s moon Europa, Saturn’s moons Enceladus and Titan are each fascinating potential targets. Our finding of phosphine gas now raises Venus as just one more place to take seriously in the search for life beyond Earth — maybe not so crazy after all.