News stories over the last few months have had a recurring focus on Mars, our neighbouring planet as we travel outwards from the Sun. Current interest is driven by a series of missions that have sent unmanned probes out to Mars and landed instruments on the planet surface. On the 9th February the United Arab Emirates successfully manoeuvred its Hope space probe into orbit around Mars, 5 days later NASA's Perseverance rover successfully landed on the planet and a month later, on the 15th March, the Chinese Tainwen-1 probe landed and deployed its Zhurong rover vehicle. Not to be left out, ESA will launch their ExoMars mission next year with the aim of landing their Rosalind Franklin rover on the Martian surface. One of the reasons for this crowd of missions all arriving at the same time is that the dynamics of Earth and Mars orbits means that their separation oscillates between ~ 50 to 400 million Km, over a 2 year cycle and 2021 provided a launch date when the two planets were at their closest, thus minimising the effort required to travel between them. Even so it still takes approximately 7 months travelling at speeds in excess of 40,000 km/hr.
Humankind has long been fascinated by this red planet, named after the Roman god of war because of its blood-like colouring. It was Galileo who in September 1610 was the first to observe Mars as a planet rather than a distant speck of red light, and in the ensuing centuries astronomers became fascinated with the details of the planet's surface that became evermore apparent. In 1877 an Italian astronomer, Giovanni Schiaperelli, observed networks of lines in the equatorial regions of Mars which he supposed to be channels and which came to be viewed by the scientific community as canals, i.e. engineered structures rather than natural formations. The American astronomer, Percival Lowell, was a strong proponent of this canal hypothesis, interpreting the linear structures seen through telescopes as irrigation channels made by an intelligent Martian race. Further visual evidence of changes in the patterns of these structures and in the extent of the polar ice caps on Mars was used to bolster his theory with conjectures that these arose from seasonal changes in crop growth and the transportation of water from the poles to lower latitudes via the canal network. This late 19th century view of an intelligent Mars is well captured through the fiction of H.G. Wells -
'Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us.'.
- H.G. Wells (1898), The War of the Worlds
Of course, today we know that there are no canals on the surface of Mars. The observations of linear structures were probably due to optical illusions created by aberrations in the lenses of early telescopes. The first detailed and direct observation of the surface was made by the Mariner 4 spacecraft during a flyby of Mars in 1965. This first encounter followed by the first landing by NASA in 1971, has led to many more Mars-missions in the intervening decades and an expanding community of nations involved in Mars exploration, as evidenced in the current crop of missions.
Throughout this time our fascination with life on Mars has continued, NASA's Perseverance has a mission aim to: 'search for signs of ancient microbial life, which will advance NASA's quest to explore the past habitability of Mars'.
Here in Wales there is a long standing research interest in Mars missions at Aberystwyth University, whose robotics research group were involved in the 2003 Beagle 2 mission to the planet. So, to find out more about the current round of Mars probes I spoke with Dr Helen Miles who works in the Department of Computer Science at Aberystwyth and is actively involved in research for the European ExoMars mission, scheduled to launch in 2022 (further details can be found here: https:// exomars.wales/).
To start us off could you tells us about the work at Aberystwyth on planetary science and your own interests in this?
Pioneering work by the late Professor Dave Barnes involved Aberystwyth researchers on the Beagle 2 project with ESA and this connection followed through to the ExoMars project. We are working on the PanCam (panoramic camera) instrument, this is the primary remote sensing instrument for the lander. The international PanCam team is led by UCL's Mullard Space Science Laboratory, research at Aberystwyth focuses on ensuring that this vision system provides detailed data analysis as well as just images of the Martian surface. The Aberystwyth team are very much the 'glue' linking different aspects of the project together. Dr Matt Gunn (Department of Physics, Aberystwyth) was brought onboard to provide optics expertise and got involved in development of a calibration target for the imaging systems. This will allow true colour correction so that the images are spectrally corrected to display the actual colour environment of Mars.
What is the spectral range of your calibration target, does it extend out into IR and UV bands?
Yes, as well as PanCam it will provide calibration for ISEM (Infra-red spectrometer for Mars), a Russian designed instrument that is mounted on the Exomars vehicle just below the panoramic camera. There are specifically-designed ceramic colour targets to calibrate this instrument in the IR spectrum.
The ESA mission is due to launch next year, is that right?
Yes, after some delays it will hopefully launch next year from Baikonur on a Russian rocket.
What is driving the current fascination with Mars, is it new or are we just more aware now?
I think people are very much more aware now because of social media. We can find things out really quickly, almost real time, whereas years ago we would have had to wait for news to reach us. That naturally drives a lot of interest plus of course there is some really exciting news, for instance China's successful landing on the planet on their very first attempt was really impressive.
Is there an ideal design for a Mars rover, do people share information?
In our area of work on the camera systems they definitely do cooperate. For example the PanCam team is also working with NASA, there is lots of interaction, sharing of software etc.
What has driven your choice of career and have you always been interested in space exploration?
I loved science at school, was born and brought up in Wales and have always enjoyed living and working here. So I went to Bangor University and then onto Aberystwyth, becoming an expert in computing. I have always been interested in computer graphics, especially how we can visualise complex data to make sense of it. I met Matt Gunn a few years ago and we started to discuss how we might collaborate. A key part of modern computer graphics attempts to make things look realistic, especially using Physics principles to render in a scientifically correct manner. For the ExoMars mission this has translated to considering the particular characteristics of light on Mars and how it is scattered - there will will be a covering of dust on everything that will affect the reflection of solar radiation from surfaces. I didn't always intend to get involved with space related work but am thankful that I did as I look forward to a Mars mission launch next year!