Detecting Organics with Dust Impact Analyzer Instruments

The dust accelerator operated at the University of Colorado is used to study how the organic content of small particulates in space can be detected and identified using dust impact analyzer instruments. The Interstellar Dust Experiment (IDEX) instrument will be launched onboard the Interstellar Mapping and Acceleration Probe (IMAP) mission in 2025 and will detect and analyze the composition of hundreds or thousands of interstellar and interplanetary dust particles from Lagrange point 1. IDEX is an instrument with a large sensitive area and high mass resolution that measures the time-of-flight mass spectra of the ions generated by the hypervelocity impact of dust particles. The laboratory version of IDEX is used to collect calibration data on dust samples of known composition. Such data are required for the interpretation of future IDEX measurements, including identifying their organic content of the detected particles. A comprehensive study was performed recently on the impact ionization properties of anthracene. Measurements were made over a wide (2 - 35 km/s) impact velocity range to investigate the strong variation of the impact spectra with the energy of the impact. Such laboratory studies are also relevant to the Surface Dust Analyzer (SUDA) and DESTINY Dust Analyzer (DDA) instruments on the Europa Clipper and DESTINY+ missions, respectively. In addition, two new laboratory capabilities are in development:  A uniquely capable laboratory setup using Near Infrared (NIR) spectroscopy and Time-of-Flight (TOF) mass spectrometry will allow measuring the physical and chemical alteration of the ice surface and organic compounds due to radiation and micrometeoroid bombardment. A newly developed ice accelerator capability will be used to characterize the impact ionization or organic-bearing compounds embedded in ice particles.