I wrote down some predictions about life in the solar system, so I can measure my predictions against what our robot probes find in the future.
Midjourney: a low resolution grainy pixelated 64kb diagram showing all the different planets and moons in the solar system where life has evolved, very poor quality, misleading information
I have a hunch that life evolves everywhere the conditions exist for it to do so. The conditions are probably fairly broad, albeit within a similar range of temperature, pressure and chemical constraints to those found on early Earth.
When the conditions exist life evolves right away, in the same way that clouds or rocks form right away wthout requiring any special magic.
I therefore expect life to have evolved on Mars, probably Venus, in the subsurface oceans of moons of the gas giants, and perhaps on places like Titan too.
That life is could still be alive today; proving it exists could be difficult, but if it is there, planned robotic missions could return data (or samples) in the 2030s and 2040s that will, at least, hint at its existence.
We might have seen some of these hints already - for example, the contested detection of phosphine in Venus’ atmosphere, the unknown mechanism behind seasonal methane release on Mars, and the complex organic molecules found in Enceladus’ plumes.
When we are able to gather spectroscopic data from the atmospheres of terrestrial exoplanets, I think can expect to find potential biosignatures there too.
I’ve added a table below listing missions (planned and actual) and studies that could provide evidence that would support or undermine what I’ve written here, which I’ll update when results are available:
|Mission or study||Year||Possible outcome||Actual outcome|
|JCMT Venus observations||2022/3||Stronger confirmation of phosphine signal in Venus’ atmosphere|
|JWST exoplanet observations||2022+||Biosignatures in exoplanet atmospheres|
|Rocket Lab Venus probe||2023||Confirmation of phosphine and/or other biosignatures in Venus’ atmosphere|
|Tianwen-3 Mars sample return||2031||Detection of complex chemistry of biological origin|
|NASA/ESA Mars sample return||2033||As above|
|Europa Clipper||2030||Detection of complex chemistry or other unusual features on Europa|
|JUICE||2031||Detection of complex chemistry as above or on other Jovian moons|
|Dragonfly||2034||Detection of complex chemistry of biological origin|
|Tianwen-4||2035||As per Europa Clipper / JUICE|
|Uranus Orbiter||2044?||Possible detection of subsurface oceans and complex chemistry in water plumes|
|Enceladus lander||2050+?||Detection of complex chemistry of biological origin|
|Human mars exploration||?||Definitive confirmation of extinct or extant life forms|
The year listed is the current planned year of orbital insertion at the target planet, but it may take years of in-situ study before results are available.
A few bonus predictions for fun:
- Mars is red because of free oxygen produced by ancient bacteria, similar to the Great Oxidation Event on Earth, and the perchlorates in Martian soil are in some way linked to the direction taken by evolution as the planet became colder and drier
- The red ice features on Europa’s surface are in some way related to the biosphere in the subsurface ocean
- Life on Venus lives in the more tolerable altitude of the atmosphere and has evolved to manipulate the planetary climate in order to preserve this layer
- Titan has an ecosystem of methanogenic life
Let’s check back in 10-20 years and see where we’re up to!