Early Scientific Influences
Backyard and camping
Star gazing
Alley Pond Park
Hayden Planetarium
Growing up in NYC in 1950’s-1960’s
Hollis, Queens:
-3 min for blast to
arrive
-slow roasting zone.
Major Influence: Science Fiction
The Plan
Major in physics, get Ph.D.
Become an astronomer
Discover the answer to the big questions:
come
How did the universe begin, what came before and what will
after?
Assuming that there are other life forms out there – how can we
make contact (or have we already)?
Is our “universe” the only universe, or is there really a parallel
universe
where there is a weak Captain Kirk and an emotional Mr.
Spock?
What really happened
Went to SUNY Stony Brook in 1970 at age of 16
Failed Physics (see above)
Spent two years studying marine invertebrate zoology
Transferred to SUNY Buffalo and chemistry major
Went to grad school at Univ of Washington in analytical chemistry
At age of 25 began academic career
Fast forward 3 decades – joined astrobiology team at RPI and
returned to those questions that motivated me to become a
scientist
What I Learned
Don’t be afraid to fail
Don’t be deterred by failure
There are NO musical, poetical, metaphysical,
pharmceutical or other short cuts to finding answers to
scientific questions
There ARE many career paths that allow us to explore
the fundamental questions that led us to become
scientists in the first place
Analytical Chemistry – the science of measurements
How can we answer questions about the nature of matter in
all forms, its behavior, interactions, origins, fate......... ?
Design techniques to probe matter:
Spectroscopy (interactions of light with matter)
Mass spectrometry
Electrochemistry
Radioactivity
Of these, spectroscopy is best suited to remote studying
extraterrestrial matter
- light penetrates space, is readily detected, travels quickly (!)
Key Concepts in Analytical Chemistry
Detectability – how low can you go?
What does it mean if a signal is NOT detectable?
Sensitivity – how small a change can be detected?
Precision – how reproducible is a measurement?
Accuracy – how close is the experimental value to
the “true value”
These concepts are fundamental to all
scientific inquiries!
Astrobiology poses enormous analytical challenges!
Measurements of distant objects using remote
observations to isolate signals of interest from large
background signals
Collection and analysis of extraterrestrial samples
without contamination
Analysis of ancient terrestrial samples that have
experienced the history of Earth
Theories of origins based only on what we can
observe today, without physicochemical context
Astrobiology Roadmap
Goal 1: Understand how life arose on the Earth.
Goal 2: Determine the general principles governing the organization of matter into living
systems.
Goal 3: Explore how life evolves on the molecular, organism, and ecosystem levels.
Goal 4: Determine how the terrestrial biosphere has co-evolved with the Earth.
Goal 5: Establish limits for life in environments that provide analogues for conditions on other
worlds.
Goal 6: Determine what makes a planet habitable and how common these worlds are in the
universe.
Goal 7: Determine how to recognize the signature of life on other worlds.
Goal 8: Determine whether there is (or once was) life elsewhere in our solar system,
particularly on Mars and Europa.
Goal 9: Determine how ecosystems respond to environmental change on time-scales relevant
to human life on Earth.
Goal 10: Understand the response of terrestrial life to conditions in space or on other planets.
Origins of Life on Earth: Some Key Questions
Did earliest life involve biomolecules as they exist now, or
earlier “proto” versions?
Work backward from life as we know it (e.g., abiotic
synthesis of RNA) AND work forward:
What molecules were in greatest abundance?
How/why did they assemble? Random chain
extension or templated?
Why “cells”? Why compartmentalize in earliest life?
Why is chirality intrinsic to (all?) life on earth and how was
one enantiomer selected over the other?
Current Projects
G/C/A/U or T - Why guanosine?
What are the effects of amino acids, sugars, other
molecules on RNA oligomerization and chirality?
How can we template formation of RNA using
particulates as well as small molecules?
Future Directions
Primitive precursors to RNA and other modern
day molecules of life
Common ancestor/single source based on DNA
which came much later
Watson-Crick
G-Tetrad
Guanosine Self-Association Leads to Gel Formation
H-bonded “G-tetrads” self-assemble (aided by metals cations) into CHIRAL
“G-wires” that further assemble into liquid crystalline phases at higher
monomer concentrations
Cholesteric Phase
Hexagonal Phase
G. Gottarelli et.al, Liquid Crystals 1997, 22, 563.
P. Mariani et.al, Biophys. J. 1998, 74, 430.
Mezzina, E. etc. Chem. Eur. J. 2001, 7(2), 388-395
Pieraccini, S. etc. Mol. Cryst. Liq. Cryst. (2003),
398 57-73
Microbes and microbial communities are often studied and
classified using 16S rDNA gene sequencing – highly
sensitive to subtle differences
We are working on
improved approaches that
will separate DNA
fragments based not only
on length but also
sequence – greatly
facilitate rapid acquisition
of data reflecting true
diversity of these complex
systems