We use Mars Orbiter Laser Altimeter (MOLA) data to measure small volcanoes in the Tempe Terra and Ceraunius Fossae regions of Mars. We find that previous geometry estimates based on imagery alone are inaccurate, but MOLA data support image-based interpretations of eruptive style. Additional information is contained in the original extended abstract.
DAVINCI is one of five Discovery-class missions selected by NASA in October 2015 for Phase A studies. Launching in November 2021 and arriving at Venus in June of 2023, DAVINCI would be the first U.S. entry probe to target Venus' atmosphere in 45 years. DAVINCI is designed to study the chemical and isotopic composition of a complete cross-section of Venus' atmosphere at a level of detail that has not been possible on earlier missions and to image the surface at optical wavelengths and process-relevant scales.
Impact features adjacent to the permanent North Polar Cap on Mars provide a unique perspective on the crater formation and modification process. Little attention has been previously paid to the dozen's of ice-associated or 'frost-filled' craters north of 70N on Mars. We have examined Mars Orbiter Laser Altimeter (MOLA) cross-sections of 13 of these features between 7ON and 82N in an effort to understand cavity modification processes potentially associated with the advance and retreat of the North Polar ice cap. Here we treat the general geometric properties of these impact features and focus attention on one almost entirely filled example (i.e., 32 km diameter, located at 77N, 89E) for which high resolution Viking Orbiter images (50 m per pixel) provide key constraints for interpreting MOLA's meter-precision topographic measurements.
As of mid-2023 at least ten missions are in development or being planned to explore Venus in the next 2 decades. Most of these emphasize atmospheric chemistry and surface/interior scientific objectives and only a few directly address past and present habitability of Venus as a primary science goal. All of the missions employ previously flight-tested platforms—Orbiters and general atmospheric probes, yet none (as of yet) plan to utilize longer-lived atmospheric platforms (e.g., balloons or airships) or landers. Thus several key questions about Venus will necessarily remain unanswered after the current wave of missions in development which will explore Venus starting in 2029 and continuing throughout the 2030s. This future-oriented perspective outlines the major scientific questions that the next-generation of missions to Venus should address for a better understanding of the planet as a system and provide a reliable comparative basis for the Venus-analogue exoplanets which can be investigated only by means of remote observations such as from the James Webb Space Telescope (JWST). This next generation of Venus missions may require long lived atmospheric platforms that either float or which “fly” at different altitudes, longer lived surface stations, and eventually samples of the atmosphere/cloud particles (aerosols) and surface returned to Earth laboratories. Although ideas for aerial platforms, long-lived landers, and missions to return atmospheric and surface samples are being conceptualized at present to be ready for upcoming international competed opportunities (e.g., NASA, ESA, ISRO, JAXA), they await further investment in technologies to provide the combination of scientific measurement capabilities and flight-system performance to make the breakthroughs that the community will expect, guided by longstanding science priorities.
