How come we’ve not found any life in space?

The universe is really big, it contains literally everything that exists ever. NASA has discovered more than 5,000 planets, but scientists have also estimated that there are about 125 billion galaxies out there. And we might only be scratching the surface. So how come we’ve yet to find any evidence of life outside of planet earth? We’ve been looking for a long time. Are we really the only special planet where things live?

It’s unlikely. All those places out there and only one has life? Surely not. We know water exists on other planets, as does the sun and oxygen. Mars, our next door neighbour, is semi-habitable and that’s only seven months away (travelling at 24,600mph for the 300million mile trip). There are other planets that are classed as habitable too, such as Proxima Centauri b. Gliese 667 Cc. Kelper-442b is actually said to be more habitable than planet Earth, but it’s really far away. So if we could live there, it’s fair to assume other things can too?

This might be where we’re going wrong. A recent point of contemplation is that perhaps the reason we haven’t found life on Mars is because we’re thinking too much through the lens of how life on Earth works. In essence, we’re assuming that life forms on other planets are going to be in some way similar to those on Earth, and we only really have the tools for discovering life on Earth, so our discovery methods are missing the signs.

And actually, often these clever tools don’t even work on Earth. Scientists have carried out studies on Earth’s oldest desert, the Namib, in Southern Africa, which is said to be about 55million years old. And they found that current technology can’t always detect signs of life there, especially when it comes to "microbial dark matter" of species that died a long time ago. Similarly, a part of the Atacama Desert in South America that is geologically similar to parts of Mars often shows minimal signs of life. A [recent study] (https://www.nature.com/articles/s41467-023-36172-1) by an international group of scientists found that on the basis of matter found in the Atacama Desert, it may be extremely difficult to detect life on other planets because the matter contains dark microbiome that is life, just extra hard to detect.

It’s a bit like doing a wordsearch and being really focussed on the one word you’re trying to find: other words might slip right under your nose. Just that, in this case, we’re focussing on certain, pre-ordained ideas of what life is, so others might simply pass us by. As humans, we can detect if a pet is living or not by its breath, its heartbeat, its movement. Can we detect if a tree is living, though? That takes a few different metrics.

There is also the possibility that whatever is out there is far more intelligent than us, and has figured out ways to be undetected by these righteous Earth folks. Recently a research group from the University of Edinburgh found that there is a chance that aliens are using quantum physics to communicate with each other, which is something we’ve not quite figured out how to do yet.

For instance, we can’t even get people to Mars and back yet – the first mission that will attempt to do this is likely to happen in the 2030s or 2040s. For all we know, aliens are zipping through Earth all the time, but they’re doing it in ways which we’ll never be able to detect. Maybe they go right past Earth and onto something more interesting, like we might when observing an insect for a few minutes before getting bored.

Exploring space is also a bit contentious, solipsistic, and arguably astrocolonialist (especially if we’re looking to take over a new planet or take minerals from them). But at the same time, we don’t know what’s out there. What if there is mutual benefit? Maybe we can find something one day which eats plastic for a living and wants to live in the seas for a bit now and then just gobbling up the stuff! Maybe their waste products can help us stop global warming! Who knows!

What’s clear is, we might want to think less like humans if we want to find out about life in other places.