Applicant — Carle Pieters

Constraints and Timing of Lunar Space Weathering [or… Space Weathering Truth and Misinformation]

It was 50 years ago when we recognized that soils from the Moon look almost nothing like the rocks from which they were derived. Returned samples from every site visited documented the disparity over and over. They provided many clues that processes are active in the space environment which alter exposed materials over time. Fast forward to the present and we are still trying to learn how to link cause and effect by looking at weathered products (effects) after literally billions of years of multiple processes in action (causes). Quite a mess! I’ll briefly review the mantra of characteristic lunar space weathered materials (redder, darker, and weaker absorptions) as well as the recognized ubiquitous presence of nano-phase (and other) opaques. Then I will delve into two areas of current research that illustrate the complexity of the problem as well as the difficulty of attaining convergence or clarity on which processes and/or conditions are most important for lunar space weathering. In making the case, I’ll discuss spectroscopy-based space weathering constraints for (1) lunar swirls and (2) a natural 2-My experiment presented by a specific returned lunar rock.

When
Wed, Feb 12, 2020
11:00 am - 12:00 pm

Where
PSI Conference Center

Constraints and Timing of Lunar Space Weathering [or… Space Weathering Truth and Misinformation]

It was 50 years ago when we recognized that soils from the Moon look almost nothing like the rocks from which they were derived. Returned samples from every site visited documented the disparity over and over. They provided many clues that processes are active in the space environment which alter exposed materials over time. Fast forward to the present and we are still trying to learn how to link cause and effect by looking at weathered products (effects) after literally billions of years of multiple processes in action (causes). Quite a mess! I’ll briefly review the mantra of characteristic lunar space weathered materials (redder, darker, and weaker absorptions) as well as the recognized ubiquitous presence of nano-phase (and other) opaques. Then I will delve into two areas of current research that illustrate the complexity of the problem as well as the difficulty of attaining convergence or clarity on which processes and/or conditions are most important for lunar space weathering. In making the case, I’ll discuss spectroscopy-based space weathering constraints for (1) lunar swirls and (2) a natural 2-My experiment presented by a specific returned lunar rock.