Could life evolve inside a gas giant?

It may seem far-fetched, but if you really think about it, it is not so implausible that life could evolve in the atmosphere of a world such as Jupiter or Saturn. Perhaps a plant that does not need soil or even a more complex animalistic organism that happens to use photosynthesis could form a base for the food chain of a planet like this. Lifeforms on gaseous planets could even survive on electrical energy from the lightning storms that often occur on gas giants. Life in a gas giant could get water from water vapor in the air, possibly being able to filter the water out of the air they breathe, hydrating themselves simply by inhaling. It is also not as far-fetched as it seems for a gas giant to be made up of breathable air. Alternatively, it is entirely possible that lifeforms in gas giants could be anaerobic (non-breathing) similar to some bacteria on Earth, therefore eliminating the need for oxygen.

Respected scientists such as Stephen Hawking and Carl Sagan have theorized that life could exist in the atmospheres of gas giants, so it’s certainly not something we should rule out.

So you may be wondering (or not depending on whether not you think like me) what life in a gas giant would be like, life in a gaseous planet would likely take on one of two forms. The first likely form being flying creatures perhaps not too dissimilar to those of Earth, and the second being a drifting balloon-like organisms that likely filter feed or use photosynthesis. (Of course, this is just speculation, and they turn out to be something much stranger.)

An organism that evolved in a gas giant would most likely not be intelligent (at least not in the way that we understand intelligence) as there is no solid material with which to make tools or hide behind, and therefore interacting with the environment in any complex way would be irrelevant to survival. A creature that has evolved in a gaseous planet would likely be camouflaged as a lack of hiding places would make them easy prey for larger organisms.

Pressure would also be important to any creature living in the atmosphere of a gas giant. Any creature living in such an environment would need way to stay afloat, and altering its altitude would give it a distinct advantage. The most energy efficient way to do this would be through buoyancy, either maintaining a density similar to that of the surrounding atmosphere, or altering the pressure of “air” trapped inside a gas bladder.

The idea of abundant ecosystems inhabiting planets such as Jupiter is by no means a new one. In 1975, Carl Sagan and Edwin Salpeter published a paper in which they speculated about what such an ecosystem might look like. Sagan and Salpeter envisioned three main types of Jovian creatures. There were sinkers, small organisms which were constantly falling to their doom in the dense and hot lower atmosphere, but producing tiny offspring that would be pushed into the relative safety of the upper atmosphere by swirling currents. The other aerial residents of Jupiter were known as floaters, which Sagan compared to enormous whales the size of cities. And then there were the hunters, complex lifeforms roaming the aerial savannah in search of prey.

Carl Sagan would later present his vision of the Jovian ecosystem to world via his immensely successful TV show, Cosmos. Here’s a clip:

In conclusion, it seems childish to project how life formed on Earth onto the rest of the cosmos, in the eloquent words of Carl Sagan “The Earth is a very small stage in a vast cosmic arena” in the vastness of the universe, it is silly to discount the possibility of life in extreme conditions, simply because Earth life cannot withstand them.

Article by Stephen Harrison