A planetary protection engineer in full-body protective gear carefully collects samples from NASA's Europa Clipper spacecraft to verify its biological cleanliness in a clean room at NASA's Jet Propulsion Laboratory on March 20, 2024. Maintaining and verifying the cleanliness of the spacecraft helps minimize the chance that microbes brought from Earth could compromise future scientific investigations at its destination, Jupiter's moon Europa. This work, referred to as planetary protection, is conducted in keeping with the international 1967 Outer Space Treaty to explore space in a responsible manner that avoids the harmful contamination of celestial bodies. This photo was taken while Europa Clipper was being built in JPL's Spacecraft Assembly Facility. Europa Clipper's three main science objectives are to determine the thickness of the moon's icy shell and its interactions with the ocean below, to investigate its composition, and to characterize its geology. The mission's detailed exploration of Europa will help scientists better understand the astrobiological potential for habitable worlds beyond our planet. https://photojournal.jpl.nasa.gov/catalog/PIA26440