Karen Rieck Presents at Lunar and Planetary Science Conference

Karen Rieck, a research scientist with the New Mexico Consortium (NMC) and a guest scientist at Los Alamos National Laboratory (LANL), recently presented her research at the 52nd Lunar and Planetary Science Conference (LPSC), held virtually March 15–19, 2021.

The Lunar and Planetary Science Conference is widely regarded as the premier international meeting for planetary science researchers. Each year, the conference brings together experts from around the world in fields including petrology, geochemistry, geophysics, geology, astronomy, and astrobiology to share the latest discoveries and advances in our understanding of the Solar System.

Rieck presented her work in a talk titled “Comparing SIMS Data for Solar Wind Na in Two Collectors Using Multiple Approaches.” The research focuses on data collected by NASA’s Genesis mission, which was designed to capture particles from the solar wind and return them to Earth for detailed laboratory analysis.

The Genesis mission provided scientists with a unique opportunity to study matter directly from the Sun. These measurements help researchers better understand the composition of the solar nebula—the cloud of gas and dust from which the Solar System formed—and provide important insights into the origins of planets, asteroids, and meteorites.

To collect solar wind particles, the Genesis spacecraft carried an array of collector materials specifically selected for their ability to capture different elements and isotopes. Using multiple collector materials allows scientists to compare measurements and verify their accuracy. While many solar wind elements have been measured in Genesis samples, relatively few have been analyzed using more than one collector material.

In this study, researchers focused on measurements of sodium (Na) collected in two different materials: diamond-like carbon (DLC) and silicon. Previous analyses revealed a puzzling discrepancy, with sodium measurements from silicon collectors often appearing nearly twice as high as those obtained from diamond-like carbon collectors. Understanding the source of this difference is important because similar collector materials are used to measure other key elements, including carbon, nitrogen, and oxygen.

Rieck and her colleagues investigated how sodium measurements from the diamond-like carbon collectors responded to different data-correction methods. Their analysis showed that the sodium measurements in the DLC collectors remained consistent within the limits of uncertainty, regardless of the correction techniques applied.

In contrast, the team found evidence suggesting that sodium measurements from the silicon collectors may be artificially elevated. However, the exact cause remains unclear. Possible explanations include contamination introduced on Earth after the samples were returned, or analytical artifacts associated with the measurement process itself.

The findings represent an important step toward improving the accuracy and reliability of solar wind measurements from the Genesis mission. Accurate elemental measurements are critical for understanding the composition of the Sun and for refining models of Solar System formation and evolution.

Future work will focus on further evaluating the data-reduction procedures used in the analysis and incorporating new ion-imaging techniques. These advanced methods have proven effective at identifying and removing signals associated with contamination, helping researchers isolate the true solar wind signal. The lessons learned from this work will ultimately be applied to measurements of additional solar wind species, improving the quality of future Genesis data analyses.

By addressing these measurement challenges, Rieck and her colleagues are helping to maximize the scientific value of the Genesis mission and deepen our understanding of the materials that formed our Solar System.

To read the abstract see: Comparing SIMS Data for Solar Wind Na in Two Collectors Using Multiple Approaches.