NASA/JPL: Onboard instruments for the detection of microscopy biosignatures

Summary: The quest for extraterrestrial life represents a critical scientific endeavor with civilization-level implications. Promising targets for exploration include icy moons in the solar system, identified for their potential as habitats due to liquid oceans. However, the lack of a precise definition of life presents a fundamental challenge to formulating detection strategies. In response to the bandwidth limitations in transmitting data from distant ocean worlds like Enceladus or Europa, an emerging discipline called Onboard Science Instrument Autonomy (OSIA) evaluates, summarizes, and prioritizes observational instrument data within flight systems. Two OSIA implementations, identifying life-like motion in digital holographic microscopy videos and cellular structure and composition through fluorescence, were developed as part of the Ocean World Life Surveyor (OWLS) prototype instrument suite at the Jet Propulsion Laboratory. Flight-like requirements and computational constraints, akin to those on the Mars helicopter, "Ingenuity," were employed to lower barriers to infusion. The study, which included evaluation using simulated and laboratory data and a live field test at the Mono Lake planetary analog site, demonstrates OSIA's potential for biosignature detection and offers insights and lessons for future mission concepts exploring the outer solar system.

Challenge: Life detection is a uniquely challenging scientific objective for two reasons. First, there remains considerable disagreement on the fundamental definition of life on Earth. Second, for any single proposed biosignature, there are processes that can generate similar, misleading signals. This is exacerbated on other planetary bodies where dominant physical processes may substantially differ from those studied on Earth. To address this, life detection missions should include the capability to detect conceptually orthogonal biosignatures that together reduce the likelihood of misinterpretation of biotic and abiotic phenomena.

While such data volumes are routinely accommodated in a laboratory setting, the need for space missions to communicate all findings across vast interplanetary distances and through over-subscribed resources like the Deep Space Network makes communication bandwidth a primary bottleneck for planetary exploration. Put simply, the compelling detection of extraterrestrial life may require over 10,000 times more raw data than is transmissible by a space mission.

How Labelbox was used: To evaluate the performance of the particle tracker and motility classifier, salient particles were manually tracked throughout each observation and annotated as motile or nonmotile. Labels were generated by external labelers from Labelbox. To ensure annotation consistency and quality, the researchers provided the labelers with a labeling guide document and video with a specific annotation protocol. All labels were then reviewed for quality by our research team. In total, 778 and 199 tracks were labeled in DHM and FLFM data, respectively. All labeled data including raw observations, labeled tracks, and the labeling guide are published in the JPL Open Repository.

You can read the full research paper here.