PhD: Spectroscopic biosignatures of microbial life on Mars

Mars (credit: NASA)

Astrobiology is the multidisciplinary field of science engaged in the search for life beyond Earth. Our planetary neighbour, Mars, shows extensive evidence for a habitable environment conducive to the origin and persistence of life early in the planet’s history. Mars has, however, since suffered an environmental collapse: the planet today is very cold and dry, and the lack of magnetic field or substantial atmosphere means the surface is bathed harmful ultraviolet and cosmic radiation. The question, therefore, is what evidence of past or present martian microorganisms might remain on or near the surface to be detectable by our future exploration rovers?

Hardy, ‘extremophile’ microbes surviving in environments on Earth that are similar to martian conditions, known as martian analogue sites, inform us about the survival limits of life and how best to search for trace signs of microbial colonists. This PhD project will work with samples from a range of such martian analogue sites around the world, as well as extremophiles cultured from them, and analyse their detectable biosignatures using a suite of spectroscopic techniques such as Raman spectroscopy, FTIR (Fourier-transform Infrared) spectroscopy, and fluorescence spectroscopy. Such spectroscopic instruments have the advantage of offering rapid, non-destructive analyses, revealing information on both the mineralogy and biosignatures within a sample, and so have been proposed or are confirmed for upcoming planetary exploration missions, including the European Space Agency’s ExoMars 2020 rover and NASA’s Mars2020 rover. Just as important as characterising what biosignatures we might anticipate to be present on the martian surface from extremophile microbes, is understanding how well these signs will persist in the harsh martian environment. Over what timeframe will detectable biosignatures be destroyed? Can we still recognise unambiguous signs of life even after they have been partially degraded? The second half of this PhD project will therefore study changes to the spectroscopic biosignatures with exposure experiments.


The student will take part in the University Graduate School and Faculty Doctoral Research Development Programme; in addition to these training programmes and the subject specific skills listed above, the student will gain important transferable skills (e.g. presentation skills, scientific writing and employability skills) to aid in future career progression.



Dartnell, L.R. et al. “Destruction of Raman Biosignatures by Ionising Radiation and the Implications for Life-Detection on Mars.” Analytical and Bioanalytical Chemistry 403.1 (2012): 131–144.

Preston, L.J. et al. “Fourier Transform Infrared Spectral Detection of Life in Polar Subsurface Environments and Its Application to Mars Exploration.” Applied Spectroscopy 69.9 (2015): 1059–1065.


Funding Notes

A number of full-time Studentships are available, to candidates with Home fee status in the Faculty of Science and Technology starting in September 2017.
The Studentships on offer are:
• Full Studentship – £16,000 annual stipend and fee waiver
• Fee Studentship – Home fee waiver


Informal enquiries:

Exoplanets classroom worksheet

This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.

This week saw the announcement of the discovery of Proxima b, an Earth-sized planet orbiting in the habitable zone of the closest star to the solar system. This is a really exciting discovery, and I thought it as good a reason as any to republish this school classroom worksheet I created on how we hunt for exoplanets.

This worksheet is suitable for A-level students (12th Grade in North America) or a good GCSE class (10th Grade in North America), and gets the students thinking about the methods used to indirectly detect exoplanets, and what information can be gleaned about the world from the telescope data.

These worksheets are intended to be used in conjunction with a teacher-lead discussion on the topics — a Problem-Based Learning exercise. Teachers Notes are also provided below.

Detecting and Characterising Exoplanets – Worksheet

Detecting and Characterising Exoplanets – Teachers’ Notes

Astrobiology Q&A

Here are just a few of the questions I’ve received from people interested in astrobiology and the search for life beyond the Earth. If you would like to know how to get involved in this sort of science, see How to become an astrobiologist.

[For my popular science book on astrobiology, Life in the Universe: A Beginner’s Guide click here.]
[For The Knowledge: How to Rebuild our World from Scratch click here]


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Leicester podcasts

On the run-up to the BBC Stargazing Live event at the University of Leicester, I recorded two podcasts, discussing the latest discoveries within astrobiology, and what we might reasonably expect an alien to look like if we ever do encounter complex life. You can listen to these both on SoundCloud, below:

How to become an astrobiologist


The Knowledge[For my popular science book on astrobiology, Life in the Universe: A Beginner’s Guide click here.]
[For The Knowledge: How to Rebuild our World from Scratch click here]


[Watch my TED talk here]


*** *** *** Apply for a PhD position with me (Deadline 24-Feb) *** *** ***

I often get emailed by people wanting to know how they can get involved in astrobiology – what A-levels or university degree they should pick to become an astrobiologist, or just how they can find out more about what’s happening right now in the field. So I thought it would be useful to compile my various responses into a single post here.

The encouraging reality is that you can get into astrobiology from pretty much any scientific background you like. I did a first degree in biology, but I have astrobiology friends who have come from physics, astronomy, chemistry, or geology. Astrobiology is a very ‘interdisciplinary’ field and sits as the Venn diagram overlap in the middle of many different kinds of science, and this breadth and diversity is exactly what makes astrobiology so exciting.

Continue reading

The Knowledge: How to Rebuild our World from Scratch

The_Knowledge_bookMaybe an asteroid hit Earth. Perhaps a nuclear war reduced our cities to radioactive rubble. Or avian flu killed most of the population. Whatever the cause, the world as we know it has ended and now the survivors must start again. But how do we set about rebuilding our world from scratch?

Once you’ve salvaged what you can from the debris, how do you grow food and make clothes? How do you generate energy and develop medicines? And once you’ve mastered the essentials, how do you smelt metals, make gunpowder, or build a primitive radio set?

The Knowledge is a guidebook for survivors. We have become disconnected not only from the beautiful fundamentals of science and technology but even from the basic skills and knowledge on which our lives and our world depend.

The Knowledge is a journey of discovery, a book which explains everything you need to know about everything. Here is the blueprint for rebooting civilisation.

It will transform your understanding of the world – and help you prepare for when it’s no longer here.

Listen to a three minute audio description of the book here

Main book website

Astrobiology – The Hunt for Alien Life

Astrobiology is a brand new field of science, encompassing research into the origins and limits of life on our own planet, and where life might exist beyond the Earth. But what actually is ‘life’ and how did it emerge on our own world? What are the most extreme conditions terrestrial life can tolerate? And what would an alien actually look like – how realistic are the life-forms envisaged by science fiction novels and films over the years? Join Dr. Lewis Dartnell on a tour of the other planets and moons in our solar system which may harbour life, and even further afield to alien worlds orbiting distant stars, to explore one of the greatest questions ever asked: are we alone…?

If you would like to book this talk please email

Hacking the Brain: What optical and auditory illusions can tell us about how the mind works

Our brain runs as an organic computer to allow us to see and hear the world around us. Optical illusions ‘hack the brain’ to disrupt this process and so allow us to understand how the brain works. With live demonstrations of a great variety of optical and auditory illusions, this talk will reveal the inner workings of the mind. Warning: you may begin to see the world in a whole new way!

If you would like to book this talk please email

Sounds of the Cosmos

crabThey say that in space no one can hear you scream, but if you took your space helmet off on Mars they could certainly hear you scream your lungs out, quite literally! Any planet or moon with an atmosphere can transmit sound, and the universe is abuzz with radio emissions which really come alive when played as audio. Hear the surface of the sun ringing like a bell, the eerie whistle from Jupiter’s intense magnetic field, the pitter-patter of the rings of Saturn, and the rapid beat of pulsars. With plenty of astounding audio recordings, this talk will transport your ears to all corners of the universe and show you what space scientists can learn from the sounds of the cosmos!

If you would like to book this talk please email


Space3DOur armada of robotic spacecraft have been giving us unrivalled close-up views of the other worlds in our solar system. We’ve snapped exquisitely detailed views of the Moon’s barren face, the rusty surface of Mars, and the myriad icy moons orbiting the bloated gas giant planets. These alien vistas, however, are very rarely seen in the glorious 3D that the latest generation of space probes are able to provide. So slip on your 3D glasses, and join Dr Lewis Dartnell as he takes you by the hand on a unique tour of our neighbouring worlds. Swoop along a deep river canyon on Mars, peer into a cavernous lunar lava tube, and experience the grainy texture of the surface rocks so realistic you can almost feel the grittiness. But most intriguingly, hear what space scientists can learn from the detailed 3D views about the exciting history of these alien landscapes and how they were formed. This is a tour of the solar system like you’ve never seen it!

If you would like to book this talk please email

Alien Evolution

alien18necaAstrobiology encompasses research into the origins and limits of life on our own planet and where else this marvellous phenomenon might have emerged. On some worlds the conditions could be stable enough to allow life to progress beyond microbes. These alien plants and animals would be subject to the same physical constraints as life on Earth, and so certain features might be universal throughout the galaxy, whereas other alien features would have evolved as ingenious solutions for survival in environments very different to Earth. So what might an alien actually look like? Building on firm scientific foundations, where evolutionary biology, astrophysics and planetary science overlap, we’ll see just how plausible are the aliens that populate our sci-fi films and TV shows.

If you would like to book this talk please email