The Environmental Model Of Mars

The twenty-two papers contained in this volume have been selected from the Proceedings of the 2nd COSPAR Colloquium. The exploration of planet Mars will be the focal point of the planetary missions in the coming years, so the investigation of the surface and the upper layers of the soil is of primary importance. The major space agencies are actively working to understand the environmental and technical requirements of the planned missions and experiments and it is predicted that the planet will be host to both ground based and atmospheric investigations in the near future.

Recent spacecraft and robotic probes to Mars have yielded data that are changing our understanding significantly about the possibility of existing or past life on that planet. Coupled with advances in biology and life-detection techniques, these developments place increasing importance on the need to protect Mars from contamination by Earth-borne organisms. To help with this effort, NASA requested that the NRC examine existing planetary protection measures for Mars and recommend changes and further research to improve such measures. This report discusses policies, requirements, and techniques to protect Mars from organisms originating on Earth that could interfere with scientific investigations. It provides recommendations on cleanliness and biological burden levels of Mars-bound spacecraft, methods to reach those levels, and research to reduce uncertainties in preventing forward contamination of Mars.

This study, commissioned by the National Aeronautics and Space Administration (NASA), examines the role of robotic exploration missions in assessing the risks to the first human missions to Mars. Only those hazards arising from exposure to environmental, chemical, and biological agents on the planet are assessed. To ensure that it was including all previously identified hazards in its study, the Committee on Precursor Measurements Necessary to Support Human Operations on the Surface of Mars referred to the most recent report from NASA's Mars Exploration Program/ Payload Analysis Group (MEPAG) (Greeley, 2001). The committee concluded that the requirements identified in the present NRC report are indeed the only ones essential for NASA to pursue in order to mitigate potential hazards to the first human missions to Mars.

Martian surface contains diverse lithologies (from sedimentary rocks to mafic-ultramafic igneous rocks) and ground patterns. These rocks record the late-stage evolution on the Martian surface from a temperate environment with bodies of liquid water to the current cold and hyper-arid environment. The constraints on the key parameters and processes for water-rock interaction, sedimentation of materials, and geomorphological development can provide important insights into the environmental change and habitability on the Martian surface. However, due to the difficulty in accessing Martian samples and limited remote-sensing data available from the Martian surface, most of the mysteries on Mars remain unraveled. In this proposed research topic we will focus on geological settings on Earth that are similar to the conditions on Mars. These Mars analogs are employed to infer possible processes on Mars and their impact on habitability and the search for life. The Mars analogs on Earth span a variety of environments, such as the super-arid sedimentary plains (e.g., the Qaidam Basin in the north of the Tibetan Plateau, the Mojave Basin in the USA, and the Atacama Desert in South America), the subsurface fracture waters in Precambrian cratons (e.g., the Canadian Shield, the Fennoscandian Shield, and the Kaapvaal Craton), high salinity localities (e.g. Laguna de Tírez, salt mines, and deep-sea brines) as well as extremely cold and highly radiative environments (e.g., polar regions, thin atmosphere). These settings on Earth are more accessible for collecting high-quality mineralogical, geochemical, geochronological, and microbiological data by the state-of-the-art facilities. These data can provide a solid cornerstone for us to understand the cycles of water and other life-essential elements, and their impact on habitability and biodiversity in extreme environments on Earth as well as the limits of life and the detection of biosignatures. Such research can also provide vital insights on the search for life on other planets and moons.

The global environment is a complex mix of interlinked processes, about which observation can tell us a great deal. This book shows how modelling can be used to explain experimental observations, and how these observations - and data gathered - can be extrapolated to explain novel situations. It also illustrates how models are actively applied.

This book contains the latest results on the plasma environment of Mars and its interaction with the solar wind. These results include mapping of the plasma environment with the instruments on Mars Express and Mars Global Surveyor, the latest numerical simulations, and theoretical studies. This comprehensive examination of the Mars environment also sets the stage for the interpretation of the Venus Express measurements.