Michael P. Callahan, Ph.D.

2008-2010: Postdoctoral Fellow | NASA Goddard Space Flight Center

2008: Ph.D. – Physical/Analytical Chemistry | University of California, Santa Barbara

2001: B.S. – Chemistry | University of Rhode Island

Extraterrestrial Organics and Prebiotic Chemistry

Meteorites provide a record of the chemical processes that occurred in the Solar System before life began on Earth.  We are interested in the organic composition of carbonaceous meteorites as well as other extraterrestrial materials.  One particular interest is nucleobases and nucleobase analogs.  Nucleobases are substituted one-ring (pyrimidine) and two-ring (purine) nitrogen heterocyclic molecules that serve as the structural basis of information storage in RNA and DNA. These molecules are essential for life as we know it and may have been essential for the origin of life on Earth. 

We have conducted targeted analyses of nucleobases in different groups of carbonaceous chondrites, discovered new nucleobase analogs in carbonaceous chondrites, and linked these meteoritic compounds to HCN chemistry.  We reported that some of the nucleobases found in meteorites are extraterrestrial in origin ending a debate that was over 50 years old (Callahan et al., PNAS, 2011).  We continue these studies by developing analytical methods and techniques for the analyses of organic compounds in complex extraterrestrial materials, elucidating potential formation pathways for nucleobases and nitrogen heterocycles, and understanding how these compounds contributed towards the formation of primitive genetic polymers (Smith et al., OLEB, 2016).

Archaeological Science

Biomolecular archaeology, the scientific analysis of ancient organic remains, has become invaluable towards understanding our human past and cultural evolution.  In collaboration with Dr. Patrick McGovern (University of Pennsylvania Museum of Archaeology and Anthropology), we analyzed Etruscan amphorae and a limestone press (ca. 425-400 B.C.) from the ancient coastal port site of Lattara in southern France (see map on right).  We developed the critical analytical methods that unambiguously identified wine biomarkers in these samples.  Direct chemical analysis along with archaeobotanical evidence and anthropological context provided the earliest proof for grape wine and viniculture from France, which is crucial to the later history of wine in Europe and the rest of the world (McGovern et al., PNAS, 2013).  We also analyzed numerous early Neolithic pottery sherds (and associated soil samples) excavated from the sites Gadachrili Gora and Shulaveris-Gora in Georgia.  Our chemical analysis, along with archaeobotanical evidence and climatic and environmental reconstruction, points to grape wine and viniculture from the Near East as early as ca. 6000 BC (McGovern et al., PNAS, 2017).  Currently, we are developing new analytical methods for organics preserved in archaeological vessels and plan to study materials from additional Neolithic sites with Dr. Pat.  We are also investigating potsherds from Askut, an ancient Egyptian island fortress on the Nile, in collaboration with Prof. Stuart Tyson Smith (University of California Santa Barbara).

K. E. Smith, C. H. House, R. D. Arevalo Jr., J. P. Dworkin, and M. P. Callahan.
“Organometallic compounds as carriers of extraterrestrial cyanide in primitive meteorites” Nature Communications 2019, volume 10, Article number: 2777. Open access article.

L. E. Rodriguez, C. H. House, K. E. Smith, M. R. Roberts, and M. P. Callahan. “Nitrogen heterocycles form peptide nucleic acid precursors in complex prebiotic mixtures” Scientific Reports 2019, volume 9, Article number: 9281. Open access article.

P. K. Thomas, G. P. Dunn, A. R. Good, M. P. Callahan, E. R. Coats, D. T. Newby, and K. P. Feris. “Semi-continuous cultivation of assembled and naturally occurring algal communities in dairy anaerobic digester effluent” Algal Research 2019, 40, 101488.

G. Manos, M. A. Balvin, and M. P. Callahan. “Integrated Circuit (IC) Chip with a Self-Contained Fluid Sensor and Method of Making the Chip” United States Patent, Patent No: US 10,189,700 B2, 2019.

P. G. Hammer, Y. R. Qin, I. Yoda, H. J. Cleaves II, and M. P. Callahan. “Solid-State Radiolysis of Nitrogen Heterocycles Provides Clues to their Abundance in the Early Solar System” International Journal of Astrobiology 2018, Published online: 2018, p. 1-7.

J. P. Dworkin, [10 authors], M. P. Callahan, [50 authors]. “OSIRIS-REx Contamination Control Strategy and Implementation” Space Science Reviews 2018, 214, Article 19 (pages 1-53).

9/1/2020 – 8/31/2021

• A PriSM for Origin of Life Chemistry – U of I flow thru

3/13/2020 – 1/12/2022

• Investigating Soluble Organic Compounds and Their Evolutions with Aqueous Alteration – NASA

3/7/2019 – 3/6/2022

• Investigating Reaction Pathways Leading to Peptide Nucleic Acid Monomers – M.J. Murdock Charitable Trust