Life could exist on Venus after all – despite its toxic clouds
Continuing our hunt to find life in the solar system outside Earth, we turn our thoughts to Venus.
Specifically, the clouds of Venus.
Venus’s cloud layer extends 30-40 miles above the surface and, unlike its blisteringly hot and high-pressure surface, actually has milder temperatures that could support some extreme forms of life.
For years, many scientists thought life might be able to survive in the clouds, but more recently the idea has been rejected based on the highly toxic droplets of sulphuric acid found throughout.
Now however, a new study from the Massachusetts Institute of Technology (MIT) has shown that the building blocks of life actually can survive in concentrated sulphuric acid – raising hopes that life could too.
The researchers found that 19 amino acids essential to life on Earth are stable for up to four weeks when placed in vials of sulphuric acid at concentrations similar to those in Venus’s clouds.
Study co-author Dr Janusz Petkowski said: ‘What is absolutely surprising is that concentrated sulphuric acid is not a solvent that is universally hostile to organic chemistry.’
The study lasted for four weeks, as the team ended the experiment when there were no further signs of activity.
Co-author Dr Sara Seager added: ‘We are finding that building blocks of life on Earth are stable in sulphuric acid, and this is very intriguing for the idea of the possibility of life on Venus.
‘It doesn’t mean that life there will be the same as here. In fact, we know it can’t be. But this work advances the notion that Venus’s clouds could support complex chemicals needed for life.’
Previously, the team has also shown that some fatty acids and nucleic acids can remain stable in sulphuric acid, but the researchers emphasise that ‘complex organic chemistry is of course not life, but there is no life without it’.
This means that just, because Venus’s clouds may be able to support life, does not mean there is life in the clouds.
Life on Venus: the lowdown
- Thirty miles up from Venus’ surface, the temperature is around 30-70C
- Pressure here is similar to Earth’s surface
- ‘Extremophile’ microbes could exist in this temperature range
- Some Russian Venera probes detect particles in Venus’ lower atmosphere about a micron in length, roughly the same size as a bacterium on Earth – but this does not mean life was found on Venus
Dr Sanjay Limaye, from the University of Wisconsin who was not involved with this study said: ‘Now, with the discovery that many amino acids and nucleic acids are stable in 98% sulphuric acid, the possibility of life surviving in [the clouds] may not be so far-fetched or fantastic.
‘Of course, many obstacles lie ahead, but life that evolved in water and adapted to sulphuric acid may not be easily dismissed.’
However, the team are well aware that Venus’s cloud chemistry is messier than test tube conditions, and still, more research needs to be done to study the trace gasses also found in the planet’s clouds.
The findings are published in the journal Astrobiology.