Whether or not there is life beyond the Earth is one of the most profound question asked by humanity, and any answer has important implications for our place in the universe. Given the size and age of the universe it seems unlikely that the Earth is the only place that has ever held life, but so far the Earth is the only planet we know of with evidence of life and our current technology limits detailed investigations to our own solar system. So out of all the planets and moons in our solar system, where are the best places to search for signs of life? And what might those signs look like?
Mars is one of our closest planetary neighbours, and over 60 years of robotic missions have provided scientists with a wealth of information on the planets current surface conditions and geological history. A history of liquid water flowing across its surface makes Mars a prime candidate in the search for past extra-terrestrial life, and some environments beneath the planet’s surface could even be habitable for life at the present. With a number of plans to send humans to Mars in the coming decades there is an urgency to finding signs of life on Mars before potential contamination by human visitors.
The search for past life on Mars is centred around the investigation of geological features that formed in the presence of water and may have been hospitable to life. Identifying these features is based on comparison to similar formations on Earth, and of key interest are formations formed in lakes and ocean environments. New research has revealed an interconnected system of lakes and river valleys on Mars, and is revealing what lake environments may have looked like and how long warm and wet environments existed. With two rovers due to land in similar environments on Mars in 2020, it may not be long before we know if there was life on Mars
About the speaker
Zach Dickeson is a Planetary Scientist based at the Natural History Museum and Birkbeck College in London, researching ancient lakes and oceans on Mars. Before studying Mars he completed a degree in Earth Geology, and his scientific background includes work in archaeology, laser eye surgery, and petroleum geology. Zach also enjoys sketching and uses science cartoons for education and outreach.
The event is carried out under a programme of, and funded by the European Space Agency (ESA).