Mark Thiemens is dean of UC San Diego’s Division of Physical Sciences. He’s also a professor of chemistry and biochemistry who could legitimately be called a “rocket scientist.” He uses rockets to understand the chemistry of the earth’s upper atmosphere and studies microscopic particulates transported globally in the atmosphere. This year, he was elected to the National Academy of Sciences, one of the highest honors bestowed to U.S. scientists and engineers. He also had a minor planet, or asteroid, named for him in August, in honor of his work with meteorites.

Thiemens: This was a complete surprise, as I did not know my name had been put forward. As someone who has been a space fanatic since I can remember, this was a really terrific surprise and honor. It was also nice because it is an honor that is permanent; your place has been carved out in the solar system. It still is hard to believe when going outside and looking up that there is an object in space that is named for you.

Thiemens: We don't work for awards and honors in science; it is really true that it is the excitement of discovery that pushes us along in our academic quests. That being said, it is also an honor to have your colleagues say that you have done extraordinarily well in this quest and to commend you for it. I am also pleased because universities are judged in part by the number of National Academy members they have, and in some way this contributes to UC San Diego's prominence. The National Academy of Sciences, which was created by Abraham Lincoln, is a significant part of U.S. scientific history. To be included as a member is indeed a fine honor.

Thiemens: Like many of my generation, the space program captured my attention. I also got started early in science with an interest in fossils and minerals. My father and mother took me at the age of seven or so to Washington University for regular lectures by the geology faculty, which typically included weekend field trips. This was excellent exposure for me and really made the excitement of science real for me, as well as the beginning of an early association with universities. When I was 13, I obtained my amateur radio license, which required learning Morse code, electronic theory, and passing an FCC exam. This required that I learn more advanced science and mathematics than I would have otherwise learned at that age. My mother and father were very supportive and helped guide me in this adventure. Some of the science we do today in fact derives directly from this early exposure.

Thiemens: The atmosphere, Earth’s surface, and oceans are a tightly coupled system. One of the least known portions of this is the Earth's upper atmosphere, for the obvious reason of difficulty of measurement. We have been engaged in one of the only rocket-borne sampling systems to achieve a much greater understanding than one would obtain from satellite measurements. Some component of what we measure is in fact a sensitive measure of what is happening at ground level; this provides a different and important perspective on the complex issue of global environmental change.

Thiemens: The simplest statement is what we all know—the earth is a connected system with no boundaries. Furthermore, the issue and impact of aerosols extends across many disciplines, with implications for climate, human health, water resources, biodiversity and economies. This is not a conclusion necessarily, nor only my discovery; it is, however, an indicator of why this is an important research area that transcends disciplines and hemispheres.

Thiemens: In the case of the South Pole, the issue one typically runs across in interactions is that climate change is part of a natural cycle and not man-made. This is not necessarily a wrong argument and is worthy of a quantitative answer. The work at the South Pole brought back information that addresses, for the first time, a very high resolution time record and definition of what is natural and what isn't. This required a lot of snow excavation, which simply put, meant digging by hand tens of tons of snow. This was done at an altitude above 9,000 feet and the temperatures in the pits were about 55 degrees below; it was not a Club Med sort of trip.

In South America, it is observed that there are numerous extinctions occurring across the biota. We became interested because of interactions with UCSD alumni Jeffrey Kent, who has been extensively involved for decades as a curator of epiphytic plants, which are highly sensitive to atmospheric change. In collaboration with him, we are beginning to try to understand how long-range transport may be irreversibly changing one of the planets most sensitive and important regions.

Thiemens: There is a rather long list here which could be argued. Clearly, water and food availability and negative changes associated with them are on the top. From my own viewpoint, the issue of aerosols and their interactions with many facets of society, such as health, climate, bio diversity, agriculture, hydrology, and visibility, is on the top of the list. It is fortunate that UC San Diego has a wonderful collection of premier faculty who are engaged in these issues; there is no place else that begins to come close in terms of breadth and quality of faculty.

Thiemens: Everything. The fact that there is no end to it and always something new to be discovered. The fact that there is always some new project and some new discipline to learn is simultaneously humbling and exciting. In spite of there being hundreds of years of scientific discovery, there still are no limits to new and significant discoveries for individuals to make.

Thiemens: I think more in terms of finding new science to accomplish rather than a formal goal. I am presently involved with a proposal to fly a spacecraft to Mars, sample the atmosphere and return. This has never been done for another planet and I would love to get this funded. I would like to push forward our understanding of the global environmental connectivity such that we might advance greater social change to achieve a better global environment. The past decades research has actually advanced to a stage where this is not a pipe dream, but rather, an achievable concept.