Did life come from space?
Did we originate beyond the stars? Milton Wainright from Sheffield University explained to Georgia Mills why he thinks it's likely...
Milton - Now my view, the one I’m working on, is that life came from space - so-called panspermia. Panspermia means seeds everywhere, so the idea is the cosmos is full of life and it floats around or it arrives in meteorites, and when it hits a planet life is delivered there. So it’s opposite to the general chemical theory which most scientists believe in, the idea that life originated on Earth. We’re saying that life does not necessarily, it could have done, originate on Earth. We think life came in from space, and it continues to come in from space as we speak.
Georgia - Why do you think this is the case?
Milton - One of the problems with the chemical origin of life is that it happened very quickly. Many people think it was too fast for it to have evolved through the chemical theory. We believe that as soon as the Earth was cool enough, imagine these organisms coming in all the time. As soon as the Earth cooled enough, then the organisms could take off, multiply, and so on, and that would be very rapid.
Georgia - How do you go about testing this or investigating this?
Milton - Neither theory can be really proven. The chemical theory - the idea that life came from chemicals. We can keep on playing with different combinations of chemicals but we can't actually prove it. What we’re doing is we’re sending balloons to the stratosphere to see if life is coming in. So the idea, basically, is that if life originated on Earth from panspermia, if it came in, then presumably it will be coming in now because nothing fundamentally has changed. If we catch life coming in, then that’s the possibility that life originated in this way.
Georgia - So you’re sending up these balloons. How do they work and what are you looking for?
Milton - Basically, the balloon goes up to a height of about 30 kilometres. It carries with it kind of a black box. Well, this opens in the stratosphere - we use GPS to locate the height and position and so on. When this drawer opens, whatever is falling falls onto these very small stubs, and these stubs can go straight into a high powered electron microscope. So anything that falls on the stubbs we can look at the surface, and this is how we do the work.
Georgia - How can you be sure what falls on the stubs is from outside of Earth?
Milton - Let me tell you what we found first. We found a number of very unusual organisms. We’ve not found them on Earth and we can use the machine to detect that they are biological. Now we don’t know what they are, so we call them biological entities. The question is, of course, the critics will say there’s plenty of stuff on Earth, there’s plenty of life on Earth; it’s just floating up to this height. I might point out that 30 kilometres is an extreme height.
When we do modeling studies we find that the only particles that could reach this height would be around 5 microns. The organisms we’re finding are 40 microns so they’re much too big, theoretically, to go to that height. The main reason we think they’re coming in is very straightforward. We do not find on our samples any grass, pollen, fungus spores. If this life was coming from Earth our samplers would be covered in this material.
The other main reason is that some of the particles form impact events - that is they form little craters. This means that they’re coming at speed. They’re not kind of lazily floating up from Earth; they’re coming from somewhere at speed. Again this is suggestive that they’re coming in from without.
Georgia - These organisms - have you found DNA in them? Tell me about them - what are they like?
Milton - Let me tell you why we know they’re organisms first of all. They have what we call bilateral symmetry; that means that they’re equal on either side. If this was a bit of fluff then you wouldn’t get this kind of bilateral symmetries. If you think of yourself, if you put a line down the middle of you, you’re equal on either side, so that tells us something; that tells us they’re organised.
The question then is are they biological? The electron microscope that we use is very fancy. We can put a crosshair on our sample, press a button, and look at the elemental composition. We find it’s made of carbon, oxygen, and a little nitrogen. Now that is the exact signature for an organism. So they’ve got form, they’ve got structure, they’re made of biological material, and this is why we think they are living organisms.
As I said before, we can’t correlate them with any known organisms but, of course, you could argue that’s just because we haven’t found them. But they're there, they’re out there and they’re coming in from the stratosphere.
Georgia - What would you need to find, or what would you need to be able to do for people to start accepting that these things are indeed from outside of Earth?
Milton - The first thing people could do was repeat our experiments of course. Science is based on repetition. But the kind of acid tests that we would like to do is what’s called an isotope fractionation. Basically, organisms are made up of carbon with different isotopes, and if an organism came from space it might have a different isotope ratio to the ones on Earth. If we could find the machine that could do this, we could again put a crosshair on our sample, press a button and get the isotope fractionation and that would tell us whether it comes from space or Earth, possibly.
The problem with all these kind of experiments is you predict them, and you think about them, and then some other problem turns up. But that’s a very, very difficult experiment because these organisms are very small, so it’s not easy.
Georgia - If you’re right and these things are from outside of Earth then you have found the first ever evidence of alien life?
Milton - Ha ha yeah, right. The trouble is convincing people and that’s the big trouble. I give talks about this all over the world and people are very sceptical, of course, as rightly they should be. But no-one yet has come up with a reason why our data is wrong. Now we call this neo panspermia - neo for new. And we’re saying, as you walk outside any building, you’re covered with these organisms from space. They’re coming in all the time, they’re coming from the year dot and this is where life, we believe, originated from.
Georgia - So we’re setting everything, searching really hard for aliens, but we’re just covered in them?
Milton - Yeah. Of course they’re extremely small so you wouldn’t see them.