Updates on the Mars Missions Analogue Sample Library

Introduction:  The Mars Missions Analogue Sample Library (ASL) was officially opened in late 2024 at the Natural History Museum in Oslo. The ASL is a coordinated NASA-ESA initiative and was developed to provide the scientific community with carefully selected terrestrial analogues from around the world for engineering, science, curation, and planetary protection needs.

The initial ASL collection was focused on samples, which were collected by NASA’s Mars 2020 Perseverance rover [1]. These first analogue sample sites were suggested by the ‘Rock Sample Team’, an expert science team, which was tasked to help identify field sites from which to collect physically representative Mars analogues. These efforts were then carried forward by the Analogue Team, a sub-group of the MSR Campaign Science Group (MCSG), which was chartered to strategically select natural samples from the field that best represent discrete components of the Jezero samples.

Since the ASL opening in 2024, new samples are being added to the collection with focus on Mars 2020 and ExoMars Rosalind Franklin missions. Updates on the ASL collection and future work will be presented at this meeting.

Mars Missions ASL Collection: The current ASL collection includes: (A) holocrystalline basalts, both aphyric and plagioclase-phyric, from Oregon, USA, (B) carbonate cemented and (C) carbonate-gypsum cemented fine sandstones/siltstones from California, (D) eolian volcanic sands from Iceland, (E) olivine cumulates from Scotland, and (F) clay-rich sedimentary rocks from juvenile deposits in southwest Iceland. The samples were selected to represent samples collected during the crater floor and delta front campaign of the Mars2020 mission. The first five samples were collected during the first field campaign in 2023 [2] and the clay-rich sedimentary rocks during a second field campaign in 2025.

Sample Requests: The ASL collection is curated at and distributed from the Natural History Museum in Oslo in collaboration with the University of Oslo (UiO). This activity is supported by the Norwegian Space Agency (NOSA) and ESA. Requests for analogue samples can be made from the ASL website with the priority of sample allocation flowing from ongoing missions to the scientific community, and then to public relations and outreach. The sample allocation process is managed by the Analogue Sample Allocation Panel (ASAP) with members from NASA, ESA, the University of Oslo and the Natural History Museum Oslo. The ASL also includes comprehensive baseline sample characterization by the Norwegian Geotechnical Institute (NGI), with reports available to the community.

Ongoing and future work:  The Analogue Team was tasked to critically evaluate the current collection and identifying any areas that need to be supplemented and continues to create a more robust ASL for the community to work with [3,4]. As a first step, the sedimentary analogue samples were reevaluated. These samples were selected to imitate the grain size, general depositional environment, and cement composition of delta front sedimentary samples in order to provide an analogue for the physical and textural properties of the returned samples. However, they are poor mineralogical or geochemical analogues for Mars. The analogue team subsequently identified two new field sites: One in Iceland and one in Italy to  collect (1) a sandstone with basaltic provenance and (2) sandstone to pebble conglomerates with an ultramafic provenance. While the Icelandic samples were collected during the field campaign in 2025, the analogue samples from Tornio Hills will be collected during the 2026 field campaign. The Analogue Team has also re-examined both, the igneous and regolith sample analogs and plans to continuously build the ASL as Perseverance continues to explore the martian surface. Moreover, the ASL is currently extended to host samples relevant to other martian missions, such as the upcoming ExoMars Rosalind Franklin mission, which will explore new terrains. Their addition to the ASL will make the analogue collection more comprehensive. Several sample request have been made since the ASL opening [e.g. 5, 6]. The Mars Missions ASL remains a key resource of strategically selected terrestrial analogue samples for the scientific community.

Acknowledgments: The authors would like to thank the members of the “Rock Sample Team” and the “Analogue Team” for their work and recommendations on terrestrial analogue samples. We also would like to thank the members of the field campaigns 2023 and 2025 for their effort to collect the analogue samples.

References:  [1] Thiessen F. et. al. (2024) Met. Soc. 2024, Abstract #6173 [2] Thiessen F. et. al. (2024) 55^th LPSC, #1208 [3] Thorpe M. T. et al. (2025), 56th LPSC, #2109 [4] Velbel et al. (2026), 57^th LPSC, #1751 [5] Ciocco et al. (2025), EPSC-DPS, #1445, [6] Willcocks et al. (2026), 57^th LPSC, #1428.