17 August 2019


The Summons Lab in August 2019.

This summer, the Summons Lab welcomed two visiting students, Nan Sun and Yongli Li, from the University of Science and Technology of China.

After weeks of labwork and analyses, the two presented their summer work to the lab group. Nan worked closely with Gareth Izon, and presented her research titled “Questioning the Paradigm of Earth’s Oxygenation.” Yongli worked with Thomas Evans, and presented “Realizing the Full Potential of Intact Polar Lipid Membrane Proxies.” Both student projects yielded fascinating insights!

Following the presentations, all headed to group dinner at MuLan — a Summons Lab tradition — to celebrate a successful summer, Nan and Yongli’s presentations, as well as group member birthdays. A convenient rotating dinner table allowed the group to be captured via video!

15 July 2019

Congratulations, Jorsua!


Summons Lab graduate student Jorsua Herrera successfully presented his Master’s thesis on July 15th — many congratulations, Jorsua!

The Summons Lab celebrated Jorsua’s success following an afternoon lab meeting.

The Summons Lab on July 15th, 2019. Photo Credit: Fatima Husain
15 July 2019
10 July 2019

How Analyzing Rocks Helps Us Communicate Science

Fatima Husain presenting at HubWeek Open Doors. Photo Courtesy: @aramphoto 
Fatima presenting on the types of instruments and methods we use to analyze rocks in the Summons Lab. Photo Courtesy: Kelsey Tsipis

On July 12th, 2019, Summons Lab member Fatima Husain gave an invited talk at HubWeek Open Doors about applying geochemistry through astrobiology and paleoclimate, and science communication. More details about HubWeek and Fatima’s talk can be found at the link below.


5 July 2019

Highlighting Women in Geobiology at MIT: Dr. Emmanuelle Grosjean

Dr. Emmanuelle Grosjean (right) with Janet Hope (left), former collaborator of Roger. Photo courtesy Dr. Emmanuelle Grosjean.

Current Role: I work as an organic geochemist for Geoscience Australia (GA), Australia’s governmental geoscientific organisation, based in Canberra. GA can be loosely described as the Australian equivalent of the US Geological Survey. In my day-to-day job, I work in a multi-disciplinary team providing insights into Australia’s energy resource potential.

Years in the Summons Lab: I started my appointment with Roger in July 2002 as his first ever post-doc! I left the Summons lab in June 2005 after 3 years of sheer academic fun.

Favorite Memories: I remember my years at MIT as thrilling because of the incredibly stimulating environment and the open-mindedness and enthusiasm of everyone. So many joyful memories to recount including the victory of the Boston Red Sox breaking the Bambino curse in 2004, but I suppose what really sticks out are my visits to the magical city of Muscat in Oman. I had the privilege to travel there three times to present results to Petroleum Development of Oman, which had been funding the study. I enjoyed interacting with the PDO staff and understanding the practical impact of our geochemical study and how it fitted the geology. I came back from these trips with many rugs in my suitcases!

MIT, Boston and Cambridge were my home for three years and I loved every minute of it. I will be forever grateful to Roger for giving me this fantastic opportunity. And whenever I get to meet Roger, it feels a little bit like coming home.

Research Foci in the Summons Lab: My main project was to study the Precambrian petroleum systems of the South Oman Salt Basin in order to better understand the source of the crude oils. I also got to collaborate and contribute to many different exciting projects, such as investigating lipids in Archaea or studying the Permian-Triassic extinction event.

Advice to Women Pursuing STEM: 

This question resonates particularly with me having a daughter aged 11, who is keen on science. My advice to young women and girls interested in pursuing STEM:

+ Surround yourself with a supportive network, family, friends, teachers, colleagues… I have been lucky to have parents who never doubted I could do well in any field I choose, including STEM. Their unwavering support was invaluable in me pursuing studies in STEM and getting a PhD in organic chemistry.

+ Dare to be ambitious and do not let anyone decide what you can or cannot do. To cite a popular self-motivational quote “Shoot for the moon. Even if you miss, you’ll land among the stars.”

+ Make sure that you thoroughly enjoy what you do. It is hard to achieve well if you don’t and this is what will sustain your motivation in the long run.

+ Do not let anyone bring you down because of derogatory comments on the way you look, the way you dress or the choices you make as a woman. Unfortunately, most women have to endure this at some point in time during their life and career. I am definitely hopeful things are improving in this regard. I have seen positive change in my own organisation thanks to the championing of our CEO.

Featured Publications:

Grosjean, E., Love, G.D., Kelly, A.E., Taylor, P.N., Summons, R.E., 2012. Geochemical evidence for an Early Cambrian origin of the “Q” oils and some condensates from north Oman. Organic Geochemistry 45, 77-90.

Grosjean, E., Love, G.D., Stalvies, C., Fike, D.A., Summons, R.E., 2009. Origin of petroleum in the Neoproterozoic-Cambrian South Oman Salt Basin. Organic Geochemistry 40, 87-110.

20 June 2019

Highlighting Women in Geobiology at MIT: Dr. Sabine Mehay

Dr. Sabine Mehay. Credit: Sabine Mehay

Current Role: I currently work as a Geochemist and Petroleum System Analyst for the oil and gas service company Schlumberger. I am based in Aachen, Germany.

Years in the Summons Lab: I was part of the Summons Lab from January 2010 until February 2011.

Favorite Memories: I have many good memories from my time at the Summons Lab. My favorite one is probably the field trip in the Canadian Arctic during the Summer 2010. I am grateful to have been given the opportunity to be part of team of scientists who spent one month up there, away from civilization. As my background is in chemistry, my field experience was limited at the time, and I learned a lot from the geologists and paleontologists on the team including identifying paleosols which I collected for analysis in the lab.

Research Foci in the Summons Lab: During my time at the Summons Lab, I worked mainly on two projects. The first one was on the paleoclimate of the Canadian Arctic across the Paleocene-Eocene transition using paleosol and shale samples collected from Ellesmere and Banks Islands. The second one was the study of microbialites (stromatolites and thrombolites), ooids and the symbiotic relationships between the various microorganisms communities responsible for these specific mat structures using the distributions of intact polar lipids, fatty acids and bacteriohopanepolyols.

Advice to Women Pursuing STEM: My advice for young women and girls interested in pursuing STEM is to believe in themselves, be curious and enthusiastic. A STEM career is not in contradiction with a well-balanced life, on the contrary the latter is more and more encouraged in the industry as well as in the academia.

Featured Publications:

Sabine Mehay, M. Hashem, L. Rouis, E. Mollianiyazov, B. Bennett, A. Stankiewicz (in prep.) Understanding lateral and vertical fluid variations in the Pliocene sand reservoirs in the Eastern South Caspian Basin. AAPG Bulletin. 

Sabine Mehay, M. Marin, T. Cassola, J.C. Chao, D.L. Hall (2019) Reconstruction of the thermal history across the Ringvassøy-Loppa Fault Complex, SW Barents Sea. Abstracts of European Geosciences Union (EGU) General Assembly, 7‐12 Apr 2019, Vienna, Austria; Geophysical Research Abstracts Vol. 21, EGU2019-15698.

17 June 2019

How to Detect Life on Mars


 Scientists from the Search for Extra-Terrestrial Genomes instrument team develop method to detect the tiniest traces of life on other planetary bodies

by Fatima Husain

Shades of Mars: Synthetic samples that mimic different regions of our neighboring world, used to validate life detection protocols. Synthesized by Angel Mojarro for the SETG team. Credit: C.E. Carr. 

When Christopher Carr visited a green sand beach in Hawaii at the age of 9, he probably didn’t think that he’d use the little olivine crystals beneath his feet to one day search for extraterrestrial life. Carr, now the science principal investigator for the Search for Extraterrestrial Genomes (SETG) instrument being developed jointly by the Department of Earth, Atmospheric and Planetary Sciences (EAPS) at MIT and Massachusetts General Hospital, works to wed the worlds of biology, geology, and planetary science to help understand how life evolved in the universe.

“Our history revealed by science is a truly incredible story,” Carr says. “You and I are a part of an unbroken chain of four billion years of evolution. I want to know more about that story.”  

SETG was initially proposed by professor of genetics at Harvard Medical School Gary Ruvkun, and has been led by planetary scientist and Vice President for Research at MIT Maria Zuber since 2005. 

As science PI of SETG, Carr, along with a large team of scientists and engineers, has helped develop instrumentation that could withstand radiation and detect DNA, a type of nucleic acid which carries genetic information in most living organisms, in space-flight environments. Now, with the advent of rover missions to Mars, Carr and his colleagues are working to fine tune the instrumentation to work on the red planet. To do that, the team needed to simulate the kinds of soils thought to preserve evidence of life on Mars, and for that, they needed a geologist. 

Angel Mojarro, a graduate student in EAPS, was up for the task. Mojarro spent months synthesizing Martian soils that represented different regions on Mars, ground truthed by Martian rover data. 

“Turns out you can buy most of the rocks and minerals found on Mars online,” Mojarro says. But not all. 

One of the hard-to-find components of the soils was olivine from the beach Carr visited as a child: “I called up my folks and said, ‘Hey, can you find the olivine sand in the basement and send me some of that?” 

After creating a collection of different Mars analog soils, Mojarro wanted to find out whether SETG could extract and detect small amounts of DNA embedded in those soils as it would do on a future Mars mission. While many technologies already exist on Earth to detect and sequence DNA, scaling down the instrumentation to fit on a rover, survive transport from Earth, and conduct high fidelity sequencing in a harsh Martian environment is a unique challenge. “That’s a whole bunch of steps no matter what the sequencing technology is right now,” Carr says. 

The SETG instrumentation has evolved and improved since its development began in 2005, and, currently, the team is working to integrate a new method, called nanopore sequencing, into their work. “In nanopore sequencing, DNA strands travel through nano-sized holes, and the sequence of bases are detected via changes in an ionic current,” Mojarro says. 

By themselves, Mojarro’s Mars analog soils didn’t contain microbes, so to test and develop nanopore sequencing of DNA in Mars analog soils, Mojarro added known quantities of spores from the bacteriumBacillus subtilisto the soils. Without the aid of human help on Mars, SETG instrumentation would need to be able to collect, purify, and enable the DNA to be sequenced, a process which usually necessitates about a microgram of DNA on Earth, Mojarro says.

Mojarro’s results using the new sequencing and preparation method pushed the limits of detection to the parts-per-billion scale — which means even the tiniest traces of life could be detected and sequenced by the instrument. 

“This doesn’t just apply to Mars … these results have implications in other fields, too,” Mojarro says. Similar methods of DNA sequencing on Earth have been used to help manage and track Ebolaoutbreaks and in medical research. And further, improvements to SETG could have important implications for planetary protection, which aims to prevent and minimize Earth-originating biological contamination of space environments. 

Even at the new detection limit for the SETG instrumentation, Mojarro was able to differentiate between human DNA and the BacillusDNA. “If we detect life on other planets,” Mojarro says, “we need a technique that can tell apart hitch-hiking microbes from Earth and Martian life.”

In their publication, Mojarro and Carr suggest that these developments may fill in some of the missing gaps in the story of life on Earth. “If there’s life on Mars, there’s a good chance it’s related to us,” Carr says, citing previous studies describing the planetary exchange of materials during the Late Heavy Bombardment period (4.1 to 3.8 billion years ago). 

If SETG detects and sequences DNA on Mars in the future, Carr says the results could “rewrite our very notion of our own origins.” 

Read more about the research here: https://www.liebertpub.com/doi/10.1089/ast.2018.1929

30 May 2019

Highlighting Women in Geobiology at MIT: Dr. Paula Welander

Story Caption: Paula Welander with her family. Credit: Paula Welander.

Current Role: I am currently an Assistant Professor in the Department of Earth System Science at Stanford.

Years in the Summons Lab: July 2010 through Dec 2012

Favorite Memories: I remember how cold the lab was! I always had to wear multiple sweatshirts under my lab coat and would have to go get tea in the middle of a lipid extraction to warm up. 🙂 But what I remember the most is the great interactions and conversations I had with the people in the lab. As microbiologist in an organic geochemistry lab, I often felt a bit out of my element, but everyone was so welcoming and super helpful in discussing my work.

Research Foci in the Summons Lab: In the Summons lab, I worked on sterol and hopanoid synthesis in the methane-consuming bacterium, Methylococcus capsulatus. I was able to develop a genetic experimental system in this organism that allowed me to identify and characterize the production of these cyclic triterpenoids in vivo.

Advice to Women Pursuing STEM: Seek out mentors that not only provide you with guidance and support in your research, but will also be an advocate for you. Roger is this kind of a mentor — he has been super supportive of me and my research ideas for many years. Also, find a support system that works for you — other people in your lab, friend and family outside of the lab, fellow grad students or postdocs in other departments, to help you navigate your career in STEM. I have found many women scientists on Twitter, particularly first-gen scientists and women of color that discuss the challenges they face in STEM, and it has been helpful for me to see that I am not the only one that faces these challenges.

I would also remind any young women and girls pursuing a STEM career to take time for themselves, away from the lab and the bench, and to do things that inspire them and that they love. Whether it is going for a run, doing science outreach, reading a funny book, going on a vacation, or binging a Netflix series, giving yourself the opportunity to take a break (and to not feel guilty about it) will, in the long run, make you a better (and happier) scientist.

Featured Publications: I have a 2013 PNAS paper with Roger covering what I worked on in his lab, identifying and characterizing the protein required to make 3-methylhopanoids in M. capsulatus. We also have a recent paper together in PNAS looking at archaeal membrane lipids — it was fun to publish with Roger again after 6 years on a completely different project!

16 May 2019

Highlighting Women in Geobiology at MIT: Dr. Jessica Whiteside

Story Caption: A field photograph of Dr. Whiteside taking core samples for paleomagnetic analysis (looking at ancient reversals in the Earth’s magnetic field) from the Late Triassic. This was for a study about the continental expression of long-term climate change and hydrological cycling that is the backdrop before the end-Triassic extinction and ascent of dinosaurs 201.5 million years ago.

Current Role: I am an associate professor of geochemistry at the University of Southampton, based in the National Oceanography Centre in Southern England. I specialize in molecular paleontology, that is, I use fossil chemical fingerprints as clues to ancient ecologies and environmental change.

Years in the Summons Lab: I was in the Summons lab in 2012, and return now and then for additional chemical explorations.

Favorite Memories: I have fond memories of a field excursion with Roger, Julio Sepulveda, and Laia Algeret (University of Zaragoza) to Zumaya, Spain. Here, we collected rock samples from the pink and white alternating layers that record the wobbles and wanders of the Earth’s axis in orbit around the time the asteroid hit the Yucatan Peninsula at the Cretaceous-Paleogene boundary 66 million years ago. As a wine connoisseur, Roger insisted on a culinary sampling of Rioja and tapas afterwards.

I really appreciate my time in the Summons lab — for Roger’s appreciation of the diversity of lab members, ideas, concepts, and innovations!

Research Foci in the Summons Lab: I worked on chemical fossils from an island off western Canada that records the end-Triassic mass extinction 201.5 million years ago. We showed how CO2 spewing into the atmosphere from massive lava eruptions led to extinction through a cascading series of environmental feedbacks, including the first evidence of toxic hydrogen sulphide poisoning in the sunlit surface waters from an open ocean site. I also worked on generating records from other mass extinction events associated with major climate change and how these speak to the habitability of life on Earth.

Advice to Women Pursuing STEM: Be persistent, don’t be afraid to reach your highest potential, and immerse yourself with multiple mentors who think both like and unlike you!

9 May 2019

Highlighting Women in Geobiology at MIT: Dr. Katherine French

Dr. Katherine French sitting at a table with Dr. Emily Matys, smiling for camera.

Story Caption: Dr. French with Dr. Emily Matys, another graduate of the Summons Lab.

Current Role: I am currently a research geochemist in the Central Energy Resource Science Center at the USGS in Denver, CO. I apply molecular and isotopic geochemistry to petroleum system research.

Years in the Summons Lab:I was a Ph.D. student in the Summons Lab from 2010 to 2014.

Favorite Memories: I have many good memories from my time in the Summons Lab, so it is impossible to pick one. Some of these memories include getting to do field work in Western Australia, where I also happened to learn how to drive stick shift from Roger. I remember having fun on the Autospec magnetic sector with Roger for some of my work. And, of course, I also have numerous good memories I formed with the friends I made in the Summons Lab, in the MIT EAPS department, and the MIT/WHOI joint program.

Research Foci in the Summons Lab: I used molecular biomarkers to explore the redox history of Earth, including mass extinctions, OAEs, and early photosynthesis in the Archean.

Advice to Women Pursuing STEM:Go for it and don’t be afraid to ask questions along the way! That’s how you get better at what you want to do.

Featured Publications: 

French, Katherine L., Christian Hallmann, Janet M. Hope, Petra L. Schoon, J. Alex Zumberge, Yosuke Hoshino, Carl A. Peters et al. “Reappraisal of hydrocarbon biomarkers in Archean rocks.” Proceedings of the National Academy of Sciences 112, no. 19 (2015): 5915-5920.

French, Katherine L., Julio Sepulveda, João Trabucho-Alexandre, D. R. Gröcke, and Roger E. Summons. “Organic geochemistry of the early Toarcian oceanic anoxic event in Hawsker Bottoms, Yorkshire, England.” Earth and Planetary Science Letters 390 (2014): 116-127.

French, K. L., D. Rocher, J. E. Zumberge, and R. E. Summons. “Assessing the distribution of sedimentary C 40 carotenoids through time.” Geobiology 13, no. 2 (2015): 139-151.