European Planetary Science Congress 2017 Press Notice
Sunday, 24th September
Lava tubes: the hidden sites for future human habitats on the Moon and Mars
Lava tubes, underground caves created by volcanic activity, could provide protected habitats large enough to house streets on Mars or even towns on the Moon, according to research presented at the European Planetary Science Congress (EPSC) 2017 in Riga. A further study shows how the next generation of lunar orbiters will be able to use radar to locate these structures under the Moon’s surface.
Lava tubes can form in two ways: ‘overcrusted’ tubes form when low-viscosity lava flows fairly close to the surface, developing a hard crust that thickens to create a roof above the moving lava stream. When the eruptions end, the conduit is drained leaving a tunnel a few metres beneath the surface. ‘Inflated’ tubes are complex and deep structures that form when lava is injected into existing fissures between layers of rock or cavities from previous flows. The lava expands and leaves a huge network of connected galleries as it forces its way to the surface. Lava tubes are found in many volcanic areas on Earth, including Lanzarote, Hawaii, Iceland, North Queensland in Australia, Sicily and the Galapagos islands. Underground networks of tubes can reach up to 65 kilometres. Space missions have also observed chains of collapsed pits and ‘skylights’ on the Moon and Mars that have been interpreted as evidence of lava tubes. Recently the NASA GRAIL mission provided detailed gravity data for the Moon that suggested the presence of enormous subsurface voids related to lava tubes below the lunar ‘Maria’, plains of basalt formed in volcanic eruptions early in the Moon’s history.
Now, researchers from the University of Padova and the University of Bologna in Italy have carried out the first systematic comparison of lava tube candidates on the Earth, Moon and Mars, based on high-resolution Digital Terrain Models (DTM) created from data from spacecraft instrumentation.
“The comparison of terrestrial, lunar and martian examples shows that, as you might expect, gravity has a big effect on the size of lava tubes. On Earth, they can be up to thirty metres across. In the lower gravity environment of Mars, we see evidence for lava tubes that are 250 metres in width. On the Moon, these tunnels could be a kilometre or more across and many hundreds of kilometres in length,” says Dr Riccardo Pozzobon, of the University of Padova. “These results have important implications for habitability and human exploration of the Moon but also for the search of extraterrestrial life on Mars. Lava tubes are environments shielded from cosmic radiation and protected from micrometeorites flux, potentially providing safe habitats for future human missions. They are also, potentially, large enough for quite significant human settlements – you could fit most of the historic city centre of Riga into a lunar lava tube.”
The work by Pozzobon and colleagues is already being used in the European Space Agency’s astronaut training programme. The teams lead a planetary geology training course called PANGAEA for the European Space Agency’s astronauts and engineers. The PANGAEA project has included a field trip and a test campaign in lava tubes in the Canary Island to familiarise the astronauts with geological research they could carry out during future missions to the Moon or Mars, as well as to test technical and operational systems. In particular, PANGAEA has focused on using laser technologies to characterise the Corona lava tube, an 8-kilometre long tunnel on Lanzarote.
However, analysis of lava tubes with DEMs requires that a collapse or a puncture from a meteorite reveals the presence of the hidden tunnel. Conventional remote sensing instruments cannot detect and characterise the lava tubes, as they cannot acquire measurements beneath the surface.
In a separate talk at EPSC, Leonardo Carrer and colleagues of the University of Trento presented a concept for a radar system specifically designed to detect lava tubes on the Moon from orbit. The radar probes beneath the lunar surface with low frequency electromagnetic waves and measures the reflected signals. This radar instrument could determine accurately the physical composition, size and shape of the caves and obtain a global map of their location.
“The studies we have developed show that a multi- frequency sounding system is the best option for detecting lava tubes of very different dimensions. The electromagnetic simulations show that lava tubes have unique electromagnetic signatures, which can be detected from orbit irrespective of their orientation to the radar movement direction. Therefore, a mission carrying this instrument would enable a crucial step towards finding safe habitats on the Moon for human colonisation,” says Carrer.
ESA Astronauts training in terrestrial lava tubes in Lanzarote during the PANGEA 2016 course. Credit: ESA/S. Sechi
ESA Astronauts training in terrestrial lava tubes in Lanzarote during the PANGEA 2016 course. Credit: ESA/L. Ricci
Checking the mineral composition of some weathered rocks with the HaloSpec Spectrometer during ESA astronaut PANGEA training course in terrestrial lava tubes in Lanzarote. Credit: ESA/L. Ricci
Artist’s impression of the radar instrument to probe for lava tubes beneath the lunar surface. Credit: NASA/U. Trento
Pangaea 2016: Taking astronauts to other planets – on Earth. Credit: ESA
Dr Riccardo Pozzobon
Department of Geosciences
University of Padova
Via G. Gradenigo 6, 35131, Padova, Italy
Remote Sensing Laboratory
Department of Information Engineering and Computer Science
University of Trento
Via Sommarive 9, I-38123 Povo, Trento, Italy
EPSC 2017 Press Officer
+44 07756 034243
EPSC 2017 Press Officer
Notes for Editors
The European Planetary Science Congress (EPSC) 2017 (www.epsc2017.eu) is taking place at the Radisson Blu Latvija in Riga, from Sunday 17 to Friday 22 September 2017. EPSC is the major European annual meeting on planetary science and in 2017 is hosted for the first time in the Baltic States. Around 800 scientists from Europe and around the world will attend the meeting and will give around 1,000 oral and poster presentations about the latest results on our own Solar System and planets orbiting other stars.
EPSC 2017 is organised by Europlanet and Copernicus Meetings. The Local Organising Committee is led by Baltics in Space, a not-for-profit organisation that is supporting 25 members centred around nine Baltic space facilities for the conference. The meeting is sponsored by Investment and Development Agency of Latvia, the Latvian Ministry of Education and Science, Latvijas Mobilais Telefons, Finnish Meteorological Institute, The Estonia-Latvia programme, The Representation of the European Commission in Latvia, the Planetary Science Institute, Latvijas Universitate and The Division for Planetary Sciences of the AAS.
Details of the Congress and a full schedule of EPSC 2017 scientific sessions and events can be found at the official website:
Since 2005, the Europlanet project has provided European’s planetary science community with a platform to exchange ideas and personnel, share research tools, data and facilities, define key science goals for the future and engage stakeholders, policy makers and European Citizens with planetary science. Europlanet is the parent organisation of the European Planetary Science Congress (EPSC), and the EPSC Executive Committee is drawn from its membership.
The Europlanet 2020 Research Infrastructure (RI) is a €9.95 million project to address key scientific and technological challenges facing modern planetary science by providing open access to state-of-the-art data, models and facilities across the European Research Area. The project was launched on 1st September 2015 and has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654208. Europlanet 2020 RI is led by the Open University, UK, and has 33 beneficiary institutions from 19 European countries.
Project website: www.europlanet-2020-ri.eu
Outreach website: www.europlanet-eu.org
Baltics in Space
The philosophy of the nonprofit organization, Baltics in Space, is to “Inventory, Identify, and Integrate” with a sprinkling of Inspiration to build a space product greater than the sum of its parts. The best resource in the space business is people. With an eye to strengthening the triple helix links (Industry, Education, Research), its planned outcomes are integrating Baltic-wide space events, compiling catalogs of skill-sets for prospective users and Baltic space project development with distributed teams and Baltic space education.