5 Can microbes survive elsewhere in the Universe?

As well as thinking about life in the Universe, you may wonder how well microbes can survive in very hostile conditions on Earth. The Open University has carried out some research on this in low Earth orbit and in extreme physical conditions on Earth.

Watch Video 4, which is an interview with a microbiologist discussing this research, then complete Activity 6.

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Transcript: Video 4 Interview with a microbiologist.

HELEN:

So so far in week five we've been looking at the survivability of microbes and bacteria inside the space station. But in actual fact, we can use the outside of the space station as an analogue for the origins of life and life in the solar system.

And amazingly, one of the lead researchers in Europe in this research works here at the Open University. So I'm joined by my colleague, Karen Olsson-Francis.

Hi Karen.

KAREN OLSSON-FRANCIS:

Hi. Nice to see you, Hellen.

HELEN:

So it's really exciting. How many times have you actually had an experiment up on the space station?

KAREN OLSSON-FRANCIS:

We've had three so far that have been up on the space station that I've been involved with. And we have another one that's going up in a few years time.

HELEN:

And so why do you need to use the space station to study the origins of life?

KAREN OLSSON-FRANCIS:

Well, we can use the outside of the space station. So we can look at all the different environmental conditions of low-earth orbit in one place.

So we use ground based experiments to look at different conditions, such as vacuum. But on the outside of the space station, we can look at the combined effect. And this gives us information about how life survived and how it could potentially have evolved in the solar system.

HELEN:

So tell me a little bit about those early experiments you did. They're called these exposed experiments on the outside of the space station. What did you find after the first time you sent all these sort of microbes up into space?

KAREN OLSSON-FRANCIS:

Well, the first lot of experiments we did was we actually sent up a piece of rock from Baire in Devon, so from the cliffs by the sea. And what we did was we exposed them to the conditions of low-earth orbit. And we selected the microorganisms that could survive these conditions.

What we found was an organism that we named fondly as OU20. And this is a green cyanobacteria which could use energy from the sun to grow.

HELEN:

So a bacteria that actually prefers to live in space almost than to live on the Earth. Can I say that?

KAREN OLSSON-FRANCIS:

Well, it survives. It doesn't like to grow. It survives in space, yes.

HELEN:

Yeah. OK.

And so then you've used that bacteria in your subsequent experiments to really test some of the conditions. What conditions have you been testing?

KAREN OLSSON-FRANCIS:

Well, what we've been looking for is we want to look at actually how these microbes can survive. And what the output is actually is to look at how we could use this information to give information to future life detection missions.

So looking at how organic molecules can be affected by these conditions. And this helps us to infer information, for example, from the exo Mars mission which will be going to Mars in the next few years.

HELEN:

And I think you're very interested as well in going even further afield, to the icy moons, to the quite extreme environments we might find on Europa or Enceladus. So do the low-earth orbit experiments help us with that as well?

KAREN OLSSON-FRANCIS:

Yes. Once again, this is really key information that we're understanding how vacuum and UV can affect biological bio signatures, these key molecules that we predict will be able to give us evidence of life.

HELEN:

So I understand that we send these rocks to space. We expose them to space for a while. How do we get them back again? How do you know what's going on, and which things are surviving, and which aren't?

KAREN OLSSON-FRANCIS:

Well, they normally come back with the astronauts. So the last lot of experiments that we received actually came back with Tim Peake. And they were actually under the seat that he was sitting on, surrounded by all his old clothes.

HELEN:

Ew.

So you're certain the bacteria you got back were not Tim's? They're definitely the ones you had

KAREN OLSSON-FRANCIS:

Yes. We're definite.

HELEN:

OK.

KAREN OLSSON-FRANCIS:

We probably should have checked that. But we're hopeful that they are.

HELEN:

So a lot of the science you're doing, it's based much more in biology and environmental science. So what's your background, Karen?

KAREN OLSSON-FRANCIS:

So my background is microbiology. So I do a lot of work in environmental sciences. So we look at biogeochemical cycling in extreme environments. I look at microbial diversity. And this gives us information about the limits of life.

HELEN:

Wow. And so getting access to space, we've learned through this [INAUDIBLE] and this course, is actually pretty difficult. It's quite difficult to get access and opportunities in microgravity environments. Can you build your whole career on that? Or are there other ways you can study this?

KAREN OLSSON-FRANCIS:

Well, what we do is we're looking at life in extreme environments, as well as an analogue for life elsewhere in the solar system.

So, for example, recently we just returned from Ethiopia from the Dallol depression. And here we had pH 0. We had salinities at 200 grammes per litre. And we had temperatures of over 100 degrees. So we were really pushing the envelope of life.

And what we're doing is, here are some samples here, looking if we can find evidence of life within them.

So firstly, if there's actually life that can grow, and also if we can find molecular bio signatures, which will help to infer information for future life detection missions.

HELEN:

So can I just pick this up a minute?

This looks a little bit like yellow salt, you know, like salt with food colouring, or maybe my son's cup experiment, which is like sugar and food colouring. What really is this?

KAREN OLSSON-FRANCIS:

So this is an iron oxide which has been formed due to the hydrothermic activities in the Dallol depression. And what we're hoping is that the microorganisms have actually been entombed within these salt crystals and we'll be able to use them to look for evidence.

So when we think of places like Mars on the surface, we know from data from the in-situ measurements, there's high salts, which could be chloride or sulphates on the surface. So this is kind of an analogue for that.

HELEN:

Wonderful.

So actually, your microgravity environments are one of many facilities that you're using as a microbiologist actually to understand the origins of life in the solar system.

KAREN OLSSON-FRANCIS:

Yes. That's right, Hellen. We're using a combination of the low-earth orbit experiments and analogue experiments to try and push the limits of our understanding.

HELEN:

And isn't it amazing that one of microbes that's most survivable in space has the name OU.

KAREN OLSSON-FRANCIS:

Yes. OU20.

[LAUGHING]

HELEN:

Very good. Karen, thank you very much.

KAREN OLSSON-FRANCIS:

Thank you.

End transcript: Video 4 Interview with a microbiologist.

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Video 4 Interview with a microbiologist.

In Video 4, the survivability of microbes on the outside of the ISS was discussed. In the ISS experiment ‘Biopan-6’, a group of tardigrades (water bears) – multicellular organisms, roughly the size of a grain of salt (Figure 5) – hold the record for the longest-lived animals in open space. Read this BBC News report [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] about the experiment.

Figure 5 A tardigrade, or water bear, which is approximately 0.2 mm long.

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This is a coloured photograph of a tardigrade or water bear.

Figure 5 A tardigrade, or water bear, which is approximately 0.2 mm long.

Amazingly, tardigrades can effectively hibernate for weeks and can ‘come back to life’ after it comes into contact with water. This is called dessication. Watch Video 5 which shows this happening.

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Video 5 Anhydrobiosis in tardigrades.

Which other organisms do you think could survive in an extreme environment? Watch Video 6 and then complete Activity 7 (which also draws on the discussion in Video 4).

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Transcript: Video 6 The life of extremophiles.

NARRATOR

360 Degrees of Separation. Extremophiles. Everyone loves an underdog, and there's one strange type of organism that proves you don't have to be the biggest or the baddest to be natures hardest. Christened extremophiles for their powers of survival in extreme places, these tiny heroes can put up with anything science and nature throw at them, acid, radiation, extreme temperatures. They just keep coming back for more.

And this has only made scientists more determined to defeat them. They've taken to sending these survivors into one of the most hostile environments imaginable. No. Outer space. But extremophiles like this one plop back down to Earth without even a mild case of travel sickness.

And this suggests a pretty sci-fi hypothesis. What if, a long time ago in a galaxy far, far away, two life-bearing planets collided. Could an extremophile have piggybacked its way to Earth on the debris? Could these sturdy survivors be the origins of life on our planet?

End transcript: Video 6 The life of extremophiles.

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Video 6 The life of extremophiles.

You will now look at the habitability of other planets.