Aditya Chopra completed his PhD research at the Australian National University’s Planetary Science Institute in 2015. He obtained an undergraduate degree in chemistry from the University of Western Australia in 2007 and in 2008 graduated with 1st class Honours in astronomy at the Australian National University.
His research areas include astrobiology and planetary science with the focus of his research being the examination of the elemental abundances in different life forms and their environments to gain insight into the origin and evolution of life.
He was recognised as a finalist for Student of the Year in the 2013 ANU Alumni Awards and was awarded the 2013 Robert Hill Memorial Prize for Interdisciplinary Research in the Earth Sciences. He also won First Prize at the 2012 Three Minute Thesis Competition’ at ANU and the Vice-Chancellor’s Community Outreach Award in 2011 for his contributions to the Mount Stromlo Observatory’s Student Outreach Program.
As a science communicator he is committed to sharing the results of his research work and passion for science through public and high school lectures, online blogs and mentoring undergraduate students. He has been interviewed on radio and featured in print at media outlets including ABC Radio, SBS Radio, Cosmos Magazine, Sydney Daily Telegraph, Community Radio 2XX, Canberra Times, Sydney Morning Herald & Australian Science Media Centre.
A CV and list of publications and activities is available at www.adi.life
Astrobiology, Planetary Science, Origin of Life, Elemental abundances in life and its environment
Thesis topic: The Origin and Evolution of Life on a Pale Blue Dot: Astrophysical, Geochemical and Biological Constraints on Habitability
Supervisor: Charles. H. Lineweaver, firstname.lastname@example.org
Research highlights & media coverage is available at www.adi.life.
Astrobiology / Origin & Evolution of Life
Since elemental composition is a relatively conserved feature of life, we describe how average bulk elemental abundances in extant life can yield an indirect estimate of relative abundances of elements in the Last Universal Common Ancestor (LUCA). The results could give us important hints about the stoichiometry of the environment where LUCA existed and perhaps clues to the processes involved in the origin and early evolution of life (Chopra et al. 2010).
We conduct a meta-analysis of studies over the last century which examined the elemental abundances in various taxa. Our compilation samples eukaryotic, bacterial and archaeal taxa across the extant tree of life. Based on the elemental abundances therein and the phylogenetic relationship between the taxa, we present an average bulk elemental composition for terrestrial life and derive our best estimate for the elemental composition of LUCA.
This reference dataset will be useful to researchers in a variety of fields in environmental, biological and planetary sciences. Our analysis could be used to identify major fractionation processes between life and its environment to better understand biological processes at an atomic and thermodynamic level, which can guide the search for extra-terrestrial life and shadow biospheres on Earth (Lineweaver and Chopra, 2012ab).
Planetary Science & Habitability
To evaluate the habitability of the increasing number of Earth-like exoplanets, we need to understand which features of our own planet enabled the origin and evolution of life and assess to what extent these features are universal (Lineweaver and Chopra (2012b).
In Lineweaver and Chopra (2012a) we evaluated the habitability of the Earth, by examining the 'bioshell' - the ∼1% volume of our planet, which is inhabited by life and described water, temperature and nutrient deserts where there is little biomass. We reviewed our understanding about the microbiology and bioenergetics of the earliest terrestrial life forms to inform us about how the habitability of Earth might have changed over the last ∼4 billion years.
Recent exoplanet detections suggest that the fraction of stars with planets is ∼100%, and that the fraction with rocky planets may be comparably large. To evaluate the habitability of exoplanets, we extended the principles of habitable zones on Earth to the circumstellar habitable zone and discussed the abiogenesis habitable zone and the galactic habitable zone.
Even if the emergence of life is a common feature of planetary systems throughout the universe, in Chopra & Lineweaver (2016), we propose a new Gaian bottleneck hypothesis that the vast majority of planetary life goes extinct early in its evolution. We postulate that planetary environments evolve away from habitable conditions within about a billion years because of the strength, rapidity and universality of abiotic positive feedbacks in the atmospheres of terrestrial planets in traditional circumstellar habitable zones.
Aditya Chopra and Charles H. Lineweaver (2016), The Case for a Gaian Bottleneck: the Biology of Habitability, Astrobiology, 16, 1, 7-22 (http://bit.ly/gaianbottleneck).
Aditya Chopra (2016), What is the history of elements in the Universe?, Chapter Section in the Astrobiology Primer 2.0., Astrobiology, in press.
Charles H. Lineweaver and Aditya Chopra (2012), Habitability of Earth and Other Earths: Astrophysical, Geochemical, Geophysical and Biological Limits on Planet Habitability, Annual Review of Earth and Planetary Sciences, Vol. 40, 597-623 (http://is.gd/annrevlc12)
Charles H. Lineweaver and Aditya Chopra (2012), What can life on Earth tell us about life in the universe? In J. Seckbach (Ed.), Genesis - In The Beginning: Precursors of Life, Chemical Models and Early Biological Evolution, Page 799-815, Springer. ISBN 978-94-007-2940-7.(http://is.gd/etlife12)
Aditya Chopra, Charles H. Lineweaver, Jochen J. Brocks and Trevor R. Ireland (2010), Palaeoecophylostoichiometrics: Searching for the Elemental Composition of the Last Universal Common Ancestor, in Australian Space Science Conference Series: 9th Conference Proceedings. Full Refereed Proceedings DVD, National Space Society of Australia Ltd, ISBN 13: 978-0-9775740 (www.tinyurl.com/ACetal10)
Aditya Chopra and Charles H. Lineweaver (2009), The major elemental abundance differences between Life, the Oceans and the Sun, in Australian Space Science Conference Series: 8th Conference Proceedings. Full Refereed Proceedings DVD, National Space Society of Australia Ltd, ISBN 13:978-0-9775740-2-5 (www.tinyurl.com/ACCL08)
Aditya Chopra (2009), What is Life made of?, The Australian National University's Undergraduate Research Journal, Volume 1, Pages 1-6, ISSN 1837-2872