The Perseverance rover landed in Jezero crater on Mars, which once contained a lake of liquid water. We report the rock properties encountered by Perseverance during a 10-kilometer traverse extending over 400 meters in elevation, from beneath Jezero's western sedimentary fan to the upper crater rim. These rocks consist of coarse-grained olivine, magnesium and iron carbonates, silica, and phyllosilicates, including some of the oldest materials exposed within Jezero. We infer that these rocks formed by olivine accumulation in an igneous system of layered intrusions, followed by exposure to water and carbon dioxide, which caused extensive carbonation of the silicate minerals. Aqueous alteration was more pronounced at lower elevations. Higher-elevation exposures on the crater rim appear similar to olivine-rich rocks distributed over the wider Nili Fossae region.
Martian carbonate-bearing rocks are compelling targets for exploration because they preserve detailed records of past aqueous processes, climate, and habitability. The Margin unit in Jezero crater is a distinct olivine- and carbonate-bearing unit stratigraphically underlying the western fan, lining the inner margin of the western crater rim and has a contested origin. Perseverance spent similar to 350 sols investigating the unit as part of its fourth mission campaign, aiming to constrain its origin, alteration history and biosignature preservation potential. This study reports on the lithofacies and stratigraphy of the unit by analyzing Mastcam-Z mosaics and derived 3D outcrop models, supplemented by long-distance SuperCam observations and detailed textural analyses from SHERLOC WATSON and ACI images. We find that the Margin unit comprises two distinct sub-units. The Eastern Margin Unit (EMU) comprises well-stratified, low-angle basinward-, rimward- and sub-horizontally inclined medium-grained sandstones which preserve angular to rounded grains, occasional cross-stratification, convex-up bedding, and erosion surfaces. The Western Margin Unit (WMU) comprises distinctly structureless to decimeter-scale parallel-layered rocks which drape the crater rim and are inclined into the crater. The origin of the WMU is uncertain but may be most consistent with a variably carbonated olivine cumulate. The favored depositional model for the EMU is a lacustrine shore zone environment where sediments derived from the adjacent WMU have been locally reworked by wave action along a paleoshoreline at around -2,400 m elevation. These observations suggest that the Margin unit preserves diverse subsurface and surface aqueous environments and further extends the habitability window at Jezero crater.
Polyphosphate kinases (PPKs) catalyze phosphoryl transfer between polyphosphates and nucleotides. Polyphosphates are a cost-effective source of phosphorylating power, making PPKs attractive enzymes for nucleotide production. However, at present, applications that require the simultaneous utilization of diverse nucleotides are not possible due to the restricted substrate profiles of PPKs. Here, we present a universal PPK capable of efficiently phosphorylating all eight common ribonucleotides (purines and pyrimidines, monophosphates and diphosphates) to triphosphates. Under optimal conditions, ~70% triphosphate conversion was observed for each substrate. To demonstrate the biotechnological potential of a universal PPK, we developed a one-pot assay for PPK-powered in vitro transcription. Primitive biology likely relied on enzyme promiscuity to support nascent metabolism with a compact proteome. This work highlights how applying the same principle to synthetic biology can facilitate the construction of complex in vitro reaction systems.
Biofilms are intricately associated with life on Earth, enabling functions essential to human and plant systems, but their susceptibility to spaceflight stressors and functional disruption in space remains incompletely understood. During spaceflight, biofilms have largely been considered as potential infrastructure, life support or infection risks. This review focuses on the prevailing beneficial roles of biofilms in human and plant health, and examines evidence of biofilm adaptability in space environments.
With the advent of long-duration lunar and Martian space missions, health risks will increase significantly as astronauts will be exposed to prolonged periods of reduced gravity, elevated radiation levels, celestial dust, and isolated environments that may interfere with psychological health and sleep. Astronauts will increasingly rely on pharmaceutical intervention to mitigate these health risks, particularly drugs targeted to treat spaceflight-induced medical conditions such as bone loss, cytopenias, and other degenerative conditions secondary to radiation exposure and immune system dysfunction. Many of these are biologic drugs, and peptide and protein pharmaceuticals are particularly unstable, with limited shelf life (∼6 months) even with refrigeration, which is inadequate for a 2+-year mission to Mars and back. In addition to reduced drug stability in space, there are mass/volume constraints, uncertainty regarding how much—if any—of the drugs will be needed, and severely limited re-supply opportunities. The National Aeronautics and Space Administration (NASA) has identified the need to establish a drug formulary for long-duration space missions, along with a process to ensure that medications remain efficacious during flight. To address these challenges, we aim to develop an “Astropharmacy,” a compact platform that uses engineered microbes to produce small doses of biologics on demand, either in transit or at space destinations that may be far from Earth. To assess the potential for this Astropharmacy, we have compiled a database of peptide and protein drugs that may be needed to mitigate the health risks during long-duration missions to the Moon and Mars that are well-suited for production by the Astropharmacy system. The compiled database acts as a guide for drugs that could be produced using the Astropharmacy system. Importantly, the database can also serve as a valuable resource for flight surgeons and the medical community on Earth, particularly those providing care in resource-limited environments, along with researchers studying biologic drug development.
