How the Martian atmosphere shapes its landscapes

An interview with Dr. Lauren Mc Keown

Dr. Lauren Mc Keown has just recently finished her PhD at Trinity, where she worked in the Geography Department as part of Professor Mary Bourke’s research team. In recent years, Bourke and her team have been conducting valuable research in collaboration with other research groups worldwide, and several of these projects have even been funded by NASA. Mc Keown’s background is in the area of planetary science, having studied physics with astronomy and space science at UCD for her undergraduate degree. Although her PhD at Trinity was in the geography department, she says that as it was centered around the planetary sciences, there was a lot of physics involved.

Her interest in astronomy stemmed from an early age. She was in awe at NASA’s detection of water on Enceladus, a tiny moon of Saturn, 500 km in diameter. It has a geyser at its south pole which is large enough to see using special wavelengths using modern telescopes. She tells me this really “fascinated” her. When she was going into fourth year she wasn’t too keen on the maths side of physics. But she decided to go along with it as the overall theory behind it did interest her and she knew she could work on her maths to “bring it up to scratch”. Her mother also managed to put her in touch with UCD Professor Lorraine Hanlon who met up with her and told her about the course there. A family visit to Florida where she got to see the Kennedy Space Centre “fueled her passion” in physics and more specifically space. She considers herself to be “very lucky” that she knew at this early age what she wanted to do in college.

After graduating she applied for an Irish Research Council Scholarship to do a summer internship at the NASA Ames Research Center. On finding out that that she had been awarded the scholarship she says she “was over the moon”. Looking back on her experience working there she says that there was a great work environment with an emphasis on inclusion and diversity of all people. While there, she worked on a space bioscience project which led to her learning a great amount from the biologists while they simultaneously learned about data analysis from her. The study sought to estimate ways to mitigate the effects of cosmic radiation on the human body while in space, which has important applications in the challenges facing long haul travel to Mars. Cosmic radiation usually causes muscle atrophy. However, studies have found that certain simple animals such as microscopic water bears are unaffected by cosmic radiation while hibernating. Investigating the induction of hibernation across these simple animals may provide us with valuable information on how it is that these animals cope with conditions which, under normal circumstances, would be lethal.

“The Martian atmosphere undergoes seasonal variation which leads to different climatic conditions during the year.”

Her PhD looked at the effects that the Martian atmosphere and its seasonal variation has on shaping the landscape. Composed almost entirely of carbon dioxide (CO2) the Martian atmosphere undergoes seasonal variation which leads to different climatic conditions during the year. Mars has seasons just like Earth because of its axial tilt which drives major temperature changes from its equivalent of winter and summer. In the poles, the process of sublimation occurs, whereby gases transition directly to their solid state and vice versa. This leads to the CO2 descending on the surface in the form of frost and ice. Then in spring the ice is heated from the bottom up and begins to evaporate. Due to the transparent nature of ice, the sun’s heat rays penetrate to the bottom of the ice and become trapped at the bottom layer where melting then begins. The ice then goes from solid to gas, building pressure up beneath the ice, leading to the ice cracking. This leads to geological formations known as ‘spiders’ on the martian surface, which get their name from their thin, elongated appearance. While this had, until now, been a hypothesis proposed by many scientists in the field, Mc Keown’s study involved lab work modelling this process. The model used a CO2 ice block on a sand bed that was contained within, using a ‘Mars chamber’ at the Open University in the UK which can recreate the low atmospheric pressure of Mars. By modelling sublimation in this experimental system, her work led to the recreation of features similar to those on Mars, providing evidence in support of this hypothesis. 

Now that she has finished her PhD, Mc Keown has recently taken up a postdoctoral research position at the Natural History Museum in London. Here she is doing a study on the origin of martian surface fragments which, after being ejected from Mars from asteroid collisions, made their way to Earth in meteorites. Mars’ low gravity is responsible for allowing these fragments to fly away in the first place. Her work seeks to determine what craters these martian meteorites originate from. Due to the large amounts of craters present on mars, she says it’s “a bit of a needle in a haystack situation” and so in the initial stages the main goal is to narrow it down to certain potential craters of origin. Geochemical data and surface maps will be used to determine the mineral composition of the rocks in the craters and their source rock. The number of craters on a given surface area can be used as an indicator to determine the age of these craters. The research here is funded by the UK space agency. Data on the size and quantity of craters is obtained using high resolution images of the Martian surface taken by an instrument known as ‘HiRISE’ on board the Mars Reconnaissance Orbiter. These images are freely available to the public as well as scientists.

“In certain fields we definitely need people from all angles of expertise”

Looking back on her PhD in Trinity, Mc Keown considers the opportunities she had to do research in other facilities to be one of the major highlights of her PhD, with the NASA experience being the most rewarding as it put a strong emphasis on the importance of transdisciplinary research which she says “in certain fields we definitely need people from all angles of expertise”. She thinks back to the time when she and her supervisor, Prof. Bourke, first found out she had been awarded the scholarship. While she says they were both “baffled” at the time as to why a physicist had been given a scholarship in a space bioscience project, the reasons for it became clear by the end of her experience there, when the Deputy Director gave a speech where he stated that this bringing together of people with different scientific backgrounds was done deliberately to promote collaboration and so that they could complement each other’s work. More so than ever before, Mc Keown says planetary science is bringing together physicists, biologists, engineers and chemists. Linking this sort of approach to group projects at an undergraduate level, she says that while often “they are the bane of everyone’s life” at the time, she feels they do “set you up for this ability to try and collaborate with other experts in different areas”.

Giving her advice to those considering the path of doing a PhD, McKeown says that people shouldn’t measure their worth off of publications or particular academic goals and that having an “outside outlet” is vital, adding that for her “doing yoga and art” contributed to her PhD as it allowed her to reach a balance. For some time she says she “used to set ridiculous unattainable goals” and when she managed to have one of the NATURE journals accept her paper for publication, it was difficult to deal with the criticisms from people who simply considered her research to be irrelevant for the paper in question. Within a year, her paper did get published but it was at this point that she realised that while it was a “wonderful thing” which she was very proud of, she understood that whether or not it had been published did not define her own worth and that of her project. While the research aspect is something she always enjoyed, it was the “people managing” that was among the more challenging elements of her studies as you need to work with senior scientists. Speaking on her own supervisor Prof. Bourke, she is extremely grateful for the guidance and encouragement she got along the way and says that she “owes getting through the PhD to her”. Ultimately, she believes that being “self-deprecating” in cases where things don’t go your way when setting “near unachievable” goals is not constructive and experiencing a setback is never the “be all, end all”. Reaching this balance, she says, is something which “every PhD student is going to have to learn to have” and that additionally, having other outlets outside of academia from which to derive self confidence is vital.  

Ciarán Ó Cuív

Ciarán Ó Cuív

Ciaran Ó Cuív is the Deputy SciTech Editor of Trinity News, and a Senior Sophister Zoology student.