The Re-Os radiometric isotope system features two of silicate Earth’s rarest elements. This couple’s unique combination of siderophile, chalcophile, and organophile properties allows it to play an outsized role, both as a geochronometer and as a source tracer, answering questions that cannot be addressed by other radiometric systems. Successive analytical breakthroughs have led to increasingly challenging and original applications that are reviewed in this issue of Elements. The Re-Os system tells us about Earth’s accretion and the evolution of the convecting and lithospheric mantle over time. Novel applications to the Earth’s crust include dating molybdenite and a host of other sulfides and oxides, deducing paleoenvironment and paleoclimate from organic material in shales, balancing continental versus oceanic–hydrothermal input to seawater, and reconstructing complex petroleum systems.

• The Re-Os Revolution: Mighty Messages from Two of Earth’s Rarest Elements
• Sulfides and Their Little Darling, Molybdenite
• Reel-to-Reel Re-Os Records—Earth System Transactions Preserved in Sediments
• Oil and Water – Intimate Conversations
• Osmium and Tungsten Isotopes Reveal Earth’s Youthful Exuberance
• The Osmium Isotope Perspective on the Dynamics of the Post-Archean Mantle

Excalibur Mineral Corporation

Isotope Tracer Technologies Inc. (IT2)

Cambridge University Press

AsiaEdit

SAMPLE RETURN THROUGHOUT THE AGES

Guest Editors: Jemma Davidson (ARES, NASA Johnson Space Center, USA) and Jessica Barnes (University of Arizona, USA)

This thematic issue of Elements will provide an overview of the mineralogical, petrological, and geochemical information learned about different planetary bodies through the study of extraterrestrial samples retrieved by both crewed and robotic missions. Sample return missions provide unique insights into the geological and chemical histories of a wide variety of celestial bodies, from the Sun and Moon to asteroids and planets. Each article—themed to a specific planetary body (e.g., the Moon, Mars) or series of bodies (e.g., asteroids, comets)—summarizes a previous mission or series of missions and their sample collection(s), and relevant current/future missions, and mission concepts. This issue focuses on the scientific benefits and discoveries gained or promised by sample return missions.

• To See a World in a Grain of Sand Jessica Barnes (University of Arizona, USA) and Jemma Davidson (ARES, NASA Johnson Space Center, USA)
• It’s Not Just a Phase: Over 50 Years of Lunar Sample Science Katherine Joy (University of Manchester, UK), Xiaochao Che (Chinese Acad. of Geological Sciences, China), Bradley Jolliff (Washington University, USA), and Jessica Barnes (University of Arizona, USA)
• Seeing Red: Retrieving Rocks from Mars and Phobos Arya Udry (University of Nevada Las Vegas, USA), Tomohiro Usui (JAXA, Japan), and Amanda Ostwald (Smithsonian Inst., USA)
• One’s Trash is Another’s Treasure: Cosmic Rubble Piles Hikaru Yabuta (Hiroshima University, Japan), Conel Alexander (Carnegie Inst. of Washington, USA), and Timothy McCoy (Smithsonian Inst., USA)
• Ice to Meet You: Sampling Cold Bodies Perry Gerakines (Goddard Space Flight Center, USA), Penny Wozniakiewicz (University of Kent, UK), and Stefanie Milam (Goddard Space Flight Center, USA).
• Space Weathering: Clear with a Chance of Solar Wind and Micrometeoroid Showers Michelle Thompson (Purdue University, USA), Amy Jurewicz (Arizona State University, USA), and Takaaki Noguchi (Kyoto University, Japan

• Birth and Growth of Minerals from Aqueous Solutions (February 2025)
• Biomineral Geochemistry: Windows into Past Climates and Calcification (April 2025)
• Greenalite – A Tiny Crystal with a Big Story (June 2025)
• Re-Os – Clock With Clout (August 2025)
• Sample Return Throughout the Ages (October 2025)
• The Variscan Orogeny in Europe – Understanding Supercontinent Formation (December 2025)