Potassium isotope composition of Mars reveals a mechanism of planetary volatile retention

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F21%3A00000123" target="_blank" >RIV/00025798:_____/21:00000123 - isvavai.cz</a>

Result on the web

<a href="https://www.pnas.org/content/118/39/e2101155118" target="_blank" >https://www.pnas.org/content/118/39/e2101155118</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1073/pnas.2101155118" target="_blank" >10.1073/pnas.2101155118</a>

Result language

angličtina

Original language name

Potassium isotope composition of Mars reveals a mechanism of planetary volatile retention

Original language description

The abundances of water and highly to moderately volatile elements in planets are considered critical to mantle convection, surface evolution processes, and habitability. From the first fly-by space probes to the more recent ‘Perseverance’ and ‘Tianwen-1’ missions, ‘follow the water’, and more broadly ‘volatiles’, has been one of the key themes of martian exploration. Ratios of volatile relative to refractory elements (e.g., K/Th, Rb/Sr) are consistent with a higher volatile content for Mars than for Earth, despite the contrasting present-day surface conditions of those bodies. This study presents K isotope data from a spectrum of martian lithologies as a new isotopic tracer for comparing the inventories of highly and moderately volatile elements and compounds of planetary bodies. Here, we show that meteorites from Mars have systematically heavier K isotopic compositions than the bulk silicate Earth (BSE), implying a greater loss of K from Mars than from Earth. The average ‘bulk silicate’ d41K values of Earth, Moon, Mars, and the asteroid 4-Vesta, correlate with surface gravity, the Mn/Na ‘volatility’ ratio, and most notably, bulk planet H2O abundance. These relationships indicate that planetary volatile abundances result from variable volatile loss during accretionary growth, where larger mass bodies preferentially retain volatile elements over lower mass objects. There is likely a threshold on the size requirements of rocky (exo)planets to retain enough H2O to enable habitability and plate tectonics, with mass exceeding that of Mars.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10505 - Geology

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Proceedings of the National Academy of Sciences of the United States of America

ISSN

0027-8424

e-ISSN

—

Volume of the periodical

118

Issue of the periodical within the volume

39 : e2101155118

Country of publishing house

US - UNITED STATES

Number of pages

7

Pages from-to

nestránkováno

UT code for WoS article

000704004200006

EID of the result in the Scopus database

2-s2.0-85115306605