FRANS SNIK

ASTRONOMER Frans Snik (1979) is an astronomer at Leiden Observatory (Leiden University, the Netherlands). His group develops advanced optical instrumentation for telescopes around the world and in space, to directly observe and characterize planets orbiting other stars than the Sun, with an ultimate goal to detect signs of extraterrestrial life in their light. To achieve an integrated approach to high-contrast imaging, Frans introduced novel liquid-crystal technology to develop broadband coronagraphs, in combination with wavefront sensing, spectroscopy, and polarimetry. His research led to the first detection of a polarization for an exoplanetary companion (DH Tau b), caused by the formation of moons. His group demonstrated the possibility of the remote detection of homochirality in chlorophyll, a strong biosignature. These activities also lead to a range of spin-off activities here on Earth: from air pollution monitoring to biomedical sensing. Frans invented the core technology of the SPEX instrument concept that is currently in-orbit as part of the NASA climate satellite PACE/SPEXone, to measure the effects of anthropogenic aerosols on our climate and our health. The development of SPEX led to the development of iSPEX; a smartphone camera add-on that enables air pollution measurements. Frans led the iSPEX project that involved thousands of citizen scientists in the Netherlands and throughout Europe to constitute a unique air pollution measurement network. Frans is currently developing the LOUPE instrument for observations of the Earth-as-an-exoplanet from the Moon, the CoNGA instrument concept for real-time imaging of trace gases, and the HYPERION instrument for medical imaging. Frans often collaborates with all kinds of scientists and scholars (biologists, engineers, social scientists, art historians, environmental scientists, medical experts), industrial partners, visual artists, policy makers, and society-at-large. He often teaches children from underprivileged backgrounds at the Weekendschool, is a curator at the Old Observatory in Leiden, and regularly appears in the media. Moreover, he is an avid collector of circularly polarized beetles, and builds Lego versions of large telescopes. In 2025, the minor planet 12941 (3.6 km diameter at 2.636 AU) was named “Franssnik”.