In our first half century as a spacefaring species we have put people on the moon, set up the International Space Station in low Earth orbit, sent two probes – Voyager 1 and 2 – on an 11 billion mile journey out of our solar system into interstellar space, discovered over 4,000 exoplanets and populated Mars with robots. However, at 93 billion light years across there are at least 100 billion galaxies within the observable universe we have yet to find. In our own Milky Way galaxy there are about 400 billion stars supporting tens of billions of solar systems with their own families of planets and many of these worlds are Earth-like. If even one of these planets is inhabited, it would change everything. It would tell us that Earth is not unique. We don’t yet know if life is a one-off accident or if it is an inevitable consequence of the universe’s evolution. We don’t really know where we came from.

Thankfully, space has a seemingly endless expanse of opportunities to solve this puzzle. It is not only a natural laboratory to discover more about the origins of life and our planet but is a vast repository of resources, and maybe one day could provide a second home for our ever-growing population. The next 100 years is going to usher in a new era in spaceflight, a time of human exploration and innovation, with commercial organisations playing an increasing role in the space industry, joining governments and space agencies to see just how far we as a species can go. In our solar system alone, we still have so much left to discover and explore if we truly desire to understand our place in the universe. As the closest celestial body to Earth, the moon is an essential starting point, not only for science but as a staging post for voyages to more distant planets, especially Mars. Right now, this red dusty frozen world is our best chance at answering a question that has existed since antiquity – are we alone?

Although seemingly alien to us today, Mars shares a similar early history to the Earth and is proving to have had conditions billions of years ago suitable for life to arise. All forms of life that we know of need water, energy and a source of carbon to exist. On Mars this means we are searching for the fingerprints of life in areas where liquid water was once present. In these now dried up locations, minerals such as clays and sulphates are found and are important as they can preserve the evidence of life, should it have arisen, for millions or even billions of years. Although we will never rule out discovering an actual living organism on Mars, the likelihood is that we will discover the carbon-based organic building blocks used to create life. In July 2020 we will be sending the ExoMars2020 rover Rosalind Franklin to Oxia Planum on Mars to search for just these types of organic ‘biosignatures’. The answer we have waited millennia for might be only a few years away.

Although tantalisingly close, Mars isn’t the only world we plan to explore looking for life. We will fly back to the gas giants to investigate features on their moons, such as the secret ocean hiding beneath the icy shell of Europa, the gargantuan jets emanating from Enceladus and the hydrocarbon lakes on Titan. We are launching telescopes and satellites to hunt for habitable exoplanets. Yet our greatest challenge to overcome in this astrobiological treasure hunt is distance. We cannot change the expanse of space we need to cross to reach even the nearest star systems and their potentially habitable planets (Alpha Centauri is a ‘mere’ 25 trillion miles away) but at our current level of technology it would take 73,796 years to get to them. As such over the coming century there will be a huge push to design and refine technologies to propel us further and faster (but safely) into the cosmos. The idea that we will find alien life, travel to and perhaps even inhabit other parts of our galaxy has become part of an image of our destiny, even evolving into a self-imposed measure of our future success.

Dr Louisa Preston

Astrobiologist and planetary geologist Dr Louisa Preston is a UK Space Agency Aurora Research Fellow and part of the science team for the ExoMars 2020 mission which will search for signatures of ancient life on Mars. She is based at The Natural History Museum in London and has worked on projects for NASA and the Canadian, European and UK Space Agencies.

The search for alien life

© Vollebak 2020

Founded in 2016, Vollebak uses science and technology to make the future of clothing happen faster. In our first four years we’ve made the world’s first Graphene Jacket using the only material in the world with a Nobel Prize, released 100 Year clothing designed to outlive you, created a Plant and Algae T Shirt grown in forests and bioreactors that turns into worm food, and designed the first jacket for deep space travel. You can find out more about us at

Sign up to see the future first: