Geoffrey A. (Geoff) Blake

Phone: 626-395-6296

Mail Code: MC 150-21

Administrative Assistant

Name: Stephanie Petty

Research Website

Personal Website

Home / People / Geoffrey A. (Geoff) Blake

Professor of Cosmochemistry and Planetary Sciences and Professor of Chemistry

B.S., Duke University, 1981; Ph.D., Caltech, 1986. Assistant Professor of Cosmochemistry, 1987-93; Associate Professor of Cosmochemistry and Planetary Sciences, 1993-97; Professor, 1997-99; Professor of Cosmochemistry and Planetary Sciences and Professor of Chemistry, 1999-. Deputy Director, Owens Valley Radio Observatory, 2000-06; Master of Student Houses, 2009-14.

Research Summary

Observational analyses of stellar and planetary genesis; THz high resolution spectroscopy and sub-ps photocarrier dynamics of hydrogen bonded and semiconductor materials; in situ characterization of the Earth's atmosphere and biogeochemical cycles.

Research Options

Geochemistry; Planetary Science;

Research Areas

Atmospheric Chemistry; Environmental Geochemistry; Extraterrestrial Geochemistry/Cosmochemistry;

Complexity is a hallmark of the natural world. For cosmochemical and geochemical systems this complexity often extends to the molecular level. During the past decade tremendous strides have been made in the chemical sciences as advances in microelectronics, lasers, materials science, etc. have all converged to produce instrumentation of unparalleled speed, sensitivity, and flexibility. For the most part these advances have been driven by technological considerations, but the application of state-of-the-art chemical techniques to astrophysics and to the earth and planetary sciences holds the potential to revolutionize the analysis of complex natural materials.

The Blake group (with links to current and past members) applies innovative spectroscopic tools to investigate the chemical and physical processes that operate in natural environments ranging from the interstellar medium to the heart of living cells. The ultimate goal of this work is a detailed understanding of the evolution of molecular diversity from atoms in the interstellar medium or from simple chemical precursors in laboratory syntheses to complex molecules and aggregates throughout the solar system, in life, and in the devices utilized by man. We carry out both remote sensing and laboratory studies, and we are actively developing new spectrometers across the Ultraviolet/Visible (UV/Vis, 200-1000 nm), Infrared (IR, 1-30 µm), and Terahertz (THz, 30-1000 µm) regions of the electromagnetic spectrum. Complementing the light source development are three major scientific areas of active research. To learn more about any of them, or about the instruments themselves, simply follow the links below.

Star formation & molecular astrophysics
Atmospheric chemistry & biogeochemistry
THz & PFI-ZEKE cluster spectroscopy
Coherent light sources & spectrometers

For a complete publications list, see my page at CaltechAUTHORS

Blake Group Thesis

"The Contribution of Molecular Line Emission to Broadband Flux Measurements at Millimeter and Submillimeter Wavelengths" Todd Groesbeck, Ph.D. Thesis (Physics, Prof. Tom Phillips, Primary Advisor), California Institute of Technology (1995).

"The Circumstellar Environment of FU Orionis Stars" Stuart McMuldroch, Ph.D. Thesis (Planetary Science, Prof. Anneila Sargent, Primary Advisor), California Institute of Technology (1995).

"Towards a More Quantitative Understanding of Intermolecular Interactions: Biologically Significant Intermolecular Clusters" Sakae Suzuki, Ph.D. Thesis (Chemistry), California Institute of Technology (1995).

"Microwave and Far-Infrared Spectroscopy of Water-containing, Hydrogen-bonded Dimers: Vibrational, Rotational, and Tunneling Dynamics" Paul Alan Stockman, Ph.D. Thesis (Chemistry), California Institute of Technology (1996).

"Spectroscopic Studies of the Gas Phase Complexes Benzene-Ammonia, Sodium-Water, and Sodium-Ammonia" David Allen Rodham, Ph.D. Thesis (Chemistry), California Institute of Technology (1997).

"THz Generation via Optical-Heterodyne Conversion: Development of a New Far-Infrared Spectrometer & Its Application toward a Better Understanding of Nonrigid Molecules" Pin Chen, Ph.D. Thesis (Chemistry), California Institute of Technology (1999).

"Development of Broadly Tunable Parametric Lasers & their Application to Alkali Metal-Small Molecule Cluster Spectroscopy" Sheng Wu, Ph.D. Thesis (Chemistry), California Institute of Technology (1999). (PDF Format, 1.3 MB)

"Photochemistry in N2O and HNO4: A Window into the Global Biogeochemistry of Nitrogen" Hui Zhang, Ph.D. Thesis (Planetary Science, Prof. Paul Wennberg, Co-Advisor), California Institute of Technology (2001). (PDF Format, 2.1 MB) (G'zipped Postscript, 5.5 MB)

"Aperture Synthesis Studies of the Chemical Composition of Protoplanetary Disks and Comets" Chunhua Qi, Ph.D. Thesis (Planetary Science), California Institute of Technology (2001). (PDF Format, 6.8 MB) (G'zipped Postscript, 6.6 MB)

"New Measurements of the Ground and v2=1 States of HDO in the 200-750 GHz Region" Melissa Kelly, M.S. Thesis (Chemical Physics), California Institute of Technology (2002).

``Gas and Dust Chemistry in Planet-Forming Disks'' Jacqueline Kessler-Silacci, Ph.D. Thesis (Chemistry), California Institute of Technology (2004). (PDF Format, 6.5 MB)

``Photophysical Properties of Protonated Aromatic Hydrocarbons,'' Vadym A. Kapinus, Ph.D. Thesis (Chemistry), California Institute of Technology (2005). (PDF Format, 9.5 MB)

``Rotational Spectroscopy and Observational Astronomy of Prebiotic Molecules'' Susanna L. Widicus Weaver, Ph.D. Thesis (Chemistry), California Institute of Technology (2005).

Theses in progress:

Rogier Braakman (Chemistry, Laboratory/astronomical THz spectroscopy)
Joanna Brown (Astronomy, Gas Dissipation Timescales in Disks)
Daniel Holland (Chemistry, Infrared fluorescence measurements of stable isotope ratios)
Matthew Kelley (Chemistry, Laboratory/astronomical spectroscopy of molecular ions)
Colette Salyk (Planetary Science, Gas versus dust probes of disks)

Ge/Ch 128. Cosmochemistry. 9 units (3-0-6); first term, 2022-23. Prerequisites: instructor's permission. Examination of the chemistry of the interstellar medium, of protostellar nebulae, and of primitive solar-system objects with a view toward establishing the relationship of the chemical evolution of atoms in the interstellar radiation field to complex molecules and aggregates in the early solar system that may contribute to habitability. Emphasis will be placed on identifying the physical conditions in various objects, timescales for physical and chemical change, chemical processes leading to change, observational constraints, and various models that attempt to describe the chemical state and history of cosmological objects in general and the early solar system in particular. Given in alternate years; not offered 2022-23.
Instructor: Blake

Ge/Ay 132. Atomic and Molecular Processes in Astronomy and Planetary Sciences. 9 units (3-0-6); second term, 2022-23. Prerequisites: instructor's permission. Fundamental aspects of atomic and molecular spectra that enable one to infer physical conditions in astronomical, planetary, and terrestrial environments. Topics will include the structure and spectra of atoms, molecules, and solids; transition probabilities; photoionization and recombination; collisional processes; gas-phase chemical reactions; and isotopic fractionation. Each topic will be illustrated with applications in astronomy and planetary sciences, ranging from planetary atmospheres and dense interstellar clouds to the early universe. Given in alternate years; offered 2022-23.
Instructor: Blake

Ge/Ch 128. Cosmochemistry. 9 units (3-0-6); first term, 2021-22. Prerequisites: instructor's permission. Examination of the chemistry of the interstellar medium, of protostellar nebulae, and of primitive solar-system objects with a view toward establishing the relationship of the chemical evolution of atoms in the interstellar radiation field to complex molecules and aggregates in the early solar system that may contribute to habitability. Emphasis will be placed on identifying the physical conditions in various objects, timescales for physical and chemical change, chemical processes leading to change, observational constraints, and various models that attempt to describe the chemical state and history of cosmological objects in general and the early solar system in particular. Given in alternate years; Offered 2021-2022.
Instructor: Blake

Ge/Ay 132. Atomic and Molecular Processes in Astronomy and Planetary Sciences. 9 units (3-0-6); first term, 2021-22. Prerequisites: instructor's permission. Fundamental aspects of atomic and molecular spectra that enable one to infer physical conditions in astronomical, planetary, and terrestrial environments. Topics will include the structure and spectra of atoms, molecules, and solids; transition probabilities; photoionization and recombination; collisional processes; gas-phase chemical reactions; and isotopic fractionation. Each topic will be illustrated with applications in astronomy and planetary sciences, ranging from planetary atmospheres and dense interstellar clouds to the early universe. Given in alternate years; not offered 2021-2022.
Instructor: Blake

Ge/Ch 128. Cosmochemistry. 9 units (3-0-6); first term, 2020-21. Prerequisites: instructor's permission. Examination of the chemistry of the interstellar medium, of protostellar nebulae, and of primitive solar-system objects with a view toward establishing the relationship of the chemical evolution of atoms in the interstellar radiation field to complex molecules and aggregates in the early solar system that may contribute to habitability. Emphasis will be placed on identifying the physical conditions in various objects, timescales for physical and chemical change, chemical processes leading to change, observational constraints, and various models that attempt to describe the chemical state and history of cosmological objects in general and the early solar system in particular. Given in alternate years; not offered 2020-21.
Instructor: Blake

Ge/Ay 132. Atomic and Molecular Processes in Astronomy and Planetary Sciences. 9 units (3-0-6); first term, 2020-21. Prerequisites: instructor's permission. Fundamental aspects of atomic and molecular spectra that enable one to infer physical conditions in astronomical, planetary, and terrestrial environments. Topics will include the structure and spectra of atoms, molecules, and solids; transition probabilities; photoionization and recombination; collisional processes; gas-phase chemical reactions; and isotopic fractionation. Each topic will be illustrated with applications in astronomy and planetary sciences, ranging from planetary atmospheres and dense interstellar clouds to the early universe. Given in alternate years; offered 2020-21.
Instructor: Blake

Ge/Ch 128. Cosmochemistry. 9 units (3-0-6); first term, 2019-20. Prerequisites: instructor's permission. Examination of the chemistry of the interstellar medium, of protostellar nebulae, and of primitive solar-system objects with a view toward establishing the relationship of the chemical evolution of atoms in the interstellar radiation field to complex molecules and aggregates in the early solar system that may contribute to habitability. Emphasis will be placed on identifying the physical conditions in various objects, timescales for physical and chemical change, chemical processes leading to change, observational constraints, and various models that attempt to describe the chemical state and history of cosmological objects in general and the early solar system in particular. Given in alternate years; offered 2019-20.
Instructor: Blake