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Home , Doppler spectroscopy, Planetary habitability

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Robin Wordsworth HBS Workshop on the Business and Economics of Space 11/4/2017 Talk Outline

• climate and habitability research – The Faint Young Paradox – Rover Landing Site Selection • research – How do exoplanet evolve? – Is remote detection possible? • Thoughts on the intersection between fundamental science and space exploitation

Abundant liquid flowed on Mars in the past…

Data and images from: Wordsworth, Ann Rev EPS, 2016 Tanaka (1987), Williams et al. (2013), Malin & Edgett (2003), Howard et al. (2005), Head & Pratt (2001) …but the climate should have been very cold!

• The young Sun was 25% fainter than it is today • Our models show that under these conditions, early Mars should have been cold enough to freeze out CO2 onto the surface • How could Mars have possibly sustained habitable conditions? ORBITER OBSERVATIONS GLOBAL VALLEY NETWORK MAP Hynek et al. 2010

MODEL / DATA R = 0.23 p < 0.001 INTERCOMPARISONS WARM SCENARIO RAINFALL

R = −0.0033 p = 0.93 COLD SCENARIO SNOWFALL

Wordsworth et al., JGR, 2015 Our ‘icy highlands’ hypothesis for the early martian climate

Wordsworth, Ann Rev EPS, 2016 Bursts of and may have warmed Mars in the past

Curiosity rover drill core Etiope et al., Icarus, 2013

Wordsworth & Pierrehumbert 2013, Science http://photojournal.jpl.nasa.gov/catalog/PIA16834 Wordsworth et al. 2017, GRL Bursts of methane and hydrogen may have warmed Mars in the past

Curiosity rover drill core Etiope et al., Icarus, 2013 ESA :

http://photojournal.jpl.nasa.gov/catalog/PIA16834 Mars 2020 Landing Site Selection

Jezero Gusev Crater

NE Syrtis Mars 2020 Landing Site Selection

http://www.americaspace.com/wp‐content/uploads/2015/08/si‐mars_w_v8.jpg : Is there life on other worlds?

Gliese 1132b: (discovered last year by Harvard CfA team)

TRAPPIST‐1 system Exoplanets: Is there life on other worlds?

Gliese 1132b: (discovered last year by Harvard CfA team)

Berta‐Thompson et al. 2016,

TRAPPIST‐1 system Observational techniques

TRANSIT HIGH‐DISPERSION

https://palereddot.org/696‐2/ Snellen et al., 2010 http://nexsci.caltech.edu/workshop/2012/talks/HeatherKnutson_124.pdf How do we look for life remotely?

Earth’s is created by life! But O2 can also be produced abiotically… LOW ATMOSPHERIC CO2 + H2O + hν  CH2O + O2

Wordsworth & Pierrehumbert (2014) HIGH EARLY ( )

Holland, 2006 Tian & Ida (2015); Luger & Barnes (2016) Models of exoplanet atmosphere evolution

ATMOSPHERIC CIRCULATION PHOTOCHEMISTRY

ATMOSPHERIC ESCAPE TO SPACE

OUTGASSING FROM INTERIOR Atmospheric Predictions

Schaefer et al., ApJ, 2016 Wordsworth et al. submitted, 2017 Atmospheric Predictions

Testable by JWST from 2019 onwards!

Morley et al., ApJ, 2017 Science Conclusions

• Mars was intermittently habitable in the past, and the most viable explanation for this is transient H2/CH4 greenhouse warming of a mainly icy early climate. • Mars 2020 Rover and Trace Gas Orbiter data will help test these ideas further, as well as many other aspects of the ’s , climate and potential for human habitation. Beyond 2020, the future of Mars exploration in the U.S. is uncertain. • ‐like exoplanets have been discovered. We are developing models to allow us to search for life on them remotely. The James Webb Space telescope and other large‐scale facilities will be able to detect the atmospheres of these and hence directly test model predictions. • Images such as this one, and space science in general, are an important public good • Traditional funding system = small amount of direct taxation, missions by national agencies (e.g. NASA) • In the knowledge economy, are there alternative ways to drive (citizen science, outreach, philanthropy, ?) that better reflect its true worth to society?

http://time.com/4003903/best‐cassini‐saturn‐photos/