Analytical Chemistry Throughout This Solar System

Abstract

One of the greatest and most long-lived scientific pursuits of humankind has been to discover and study the planetary objects comprising our solar system. Information gained from solar system observations, via both remote sensing and in situ measurements, is inherently constrained by the analytical (often chemical) techniques we employ in these endeavors. The past 50 years of planetary science missions have resulted in immense discoveries within and beyond our solar system, enabled by state-of-the-art analytical chemical instrument suites on board these missions. In this review, we highlight and discuss some of the most impactful analytical chemical instruments flown on planetary science missions within the last 20 years, including analytical techniques ranging from remote spectroscopy to in situ chemical separations. We first highlight mission-based remote and in situ spectroscopic techniques, followed by in situ separation and mass spectrometry analyses. The results of these investigations are discussed, and their implications examined, from worlds as close as Venus and familiar as Mars to as far away and exotic as Titan. Instruments currently in development for planetary science missions in the near future are also discussed, as are the promises their capabilities bring. Analytical chemistry is critical to understanding what lies beyond Earth in our solar system, and this review seeks to highlight how questions, analytical tools, and answers have intersected over the past 20 years and their implications for the near future. Expected final online publication date for the Annual Review of Analytical Chemistry Volume 15 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

In situ organic biosignature detection techniques for space applications

“…Previous review papers have primarily covered chemical analysis instruments previously used in spaceflight applications. Seaton et al (2021), Seaton et al (2022) have summarized analytical techniques and instruments used in previous and planned spaceflight missions; including those used for organic biosignature detection, inorganic analysis, and remote sensing; but also covered instruments used in space probes in addition to lander missions. Poinot and Geffroy-Rodier (2015) have provided a detailed overview of previous spaceflight-GC instruments used for organic detection.…”

Infrared Photodissociation Spectroscopy of Water-Tagged Ions with a Widely Tunable Quantum Cascade Laser for Planetary Science Applications

“…Priorities outlined in the Planetary Science Decadal Survey encourage the development of sensor platforms capable of biomolecular detection in physiochemically relevant environments (icy worlds, Titan, Mars polar regions) with several concept missions encouraging elements that include mass detection and liquid sampling . Mass spectrometric detection alone has limitations in identifying analytes and is thus often coupled with front-end separation techniques with such platforms already in development for planetary science applications. , A possible alternative or complement to front-end separation is to implement action spectroscopic techniques that provide vibrational spectra of mass-selected ions with ion-counting sensitivity. A spaceborne in situ sensor could then supplement information from traditional one-dimensional mass analysis with an orthogonal infrared (IR) channel, allowing for the spectroscopic identification of molecule classes or even the quantification of isomeric mixture components.…”