4 September 2019 - An international team of scientists, co-funded by STFC, believe they have found one answer to how water appeared on the surface of Mars. They have analysed Martian meteorites and discovered unprecedented details about how asteroid impacts can help to create temporary sources of running water on Mars.
Scientists have long been fascinated by signs that there was once running water on Mars, as this means there may have been, or could still be, life on the red planet. But, although there is evidence that water did once flow on the planet’s surface, how the water got there has been rather a mystery – until now.
This study, funded by STFC and led by the University of Glasgow, helps to narrow down the potential location of the impact crater on the Martian surface which blasted some of those Martian rocks into space millions of years ago.
Planetary scientists used a technique known as electron backscatter diffraction to examine slices of two different Martian meteorites known as ‘nakhlites’ – this technique allowed the team to reconstruct the major events that shaped the rock since it formed on Mars around 1.4 billion years ago.
The nakhlites are group of volcanic Martian meteorites named after El Nakhla in Egypt, where the first of them fell to Earth in 1911. Patterns on these meteorites suggest there was liquid water on the Martian surface approximately 633 million years ago.
Lead author Dr Luke Daly, of the University of Glasgow, said: “There’s a huge amount of information about Mars locked inside the little pieces of the red planet which have fallen to Earth as meteorites, which new analytical techniques can allow us to access.
“By applying this electron backscatter diffraction technique, we’ve been able to look very closely at the orientation and deformation of minerals across the whole area of these samples of Martian rock to look for patterns.”
The team discovered that two big events happened on Mars to help create these meteorites – the first being that an asteroid crashed into the planet 633 million years ago, the heat of which melted the ice under the planet’s surface and sent water rushing through the cracks.
Dr Daly added: “The second exciting thing it tells us is that the rocks must have been hit twice. A second impact about 11 million years ago had the right combination of angle and force to blast the rocks off the surface of the planet and begin their long journey through space towards Earth.”
The team believe that this suggests regular asteroid bombardments could have created temporary hydrothermal systems all over the planet and important sources of liquid water.
For more information on the study, visit the University of Glasgow website.
Last updated: 04 September 2019