Examinando por Autor "McConnochie, Timothy"

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Acceso Abierto
Detection of visible-wavelength aurora on Mars
(Science, 2025-05-14) Knutsen, Elise; McConnochie, Timothy; Lemmon, M. T.; Donaldson, Chris; Francis, Raymond; Legett, Carey; Viet, Shayla; Soret, Lauriane; Toledo, D.; Apéstigue, Víctor; Witasse, Olivier; Montmessin, F.; Jolitz, Rebecca; Schneider, Nicolas; Tamppari, L. K.; Cousin, Agnes; Wiens, Roger; Maurice, Sylvestre; Bell, James; Forni, Olivier; Lasue, Jeremie; Pilleri, Paolo; Bertrand, T.; Patel, P.; Schröder, Susanne; Curry, Shannon; Lee, Christina; Rahmati, Ali; National Aeronautics and Space Administration (NASA); Belgian National Fund for Scientific Research; Jet Propulsion Laboratory; Norges Forskningsråd
Mars hosts various auroral processes despite the planet’s tenuous atmosphere and lack of a global magnetic field. To date, all aurora observations have been at ultraviolet wavelengths from orbit. We describe the discovery of green visible-wavelength aurora, originating from the atomic oxygen line at 557.7 nanometers, detected with the SuperCam and Mastcam-Z instruments on the Mars 2020 Perseverance rover. Near–real-time simulations of a Mars-directed coronal mass ejection (CME) provided sufficient lead-time to schedule an observation with the rover. The emission was observed 3 days after the CME eruption, suggesting that the aurora was induced by particles accelerated by the moving shock front. To our knowledge, detection of aurora from a planetary surface other than Earth has never been reported, nor has visible aurora been observed at Mars. This detection demonstrates that auroral forecasting at Mars is possible, and that during events with higher particle precipitation, or under less dusty atmospheric conditions, aurorae will be visible to future astronauts.
Acceso Abierto
First detection of visible-wavelength aurora on Mars
(Europlanet, 2024-07-03) Wright Knutsen, Elise; McConnochie, Timothy; Lemmon, M. T.; Tamppari, L. K.; Viet, Shayla; Cousin, Agnes ; Wiens, Roger; Francis, Raymond; Donaldson, Chris ; Lasue, J.; Forni, Olivier; Patel, P.; Schneider, Nick; Toledo, D.; Apéstigue, Víctor
Auroras are hallmarks of the interaction between solar particles and the atmosphere of planets. Martian aurora was first discovered in 2005, since then, four different types have been identified: localized discreet aurora (Bertaux et al., 2005), global diffuse aurora (Schneider et al., 2015), dayside proton aurora (Deighan et al., 2018), and large-scale sinuous aurora (Lillis et al., 2022). All previous detections have been made in the UV from orbit. Here we present, from observations with the SuperCam and MastCam-Z instruments on the Mars 2020 Perseverance rover, the first detection of aurora from the Martian surface and the first detection of the green 557.7 nm atomic oxygen auroral emission on Mars. This is the same emission line that is familiar from terrestrial aurora. Charged particles accelerated by interplanetary coronal mass ejections (ICMEs) or solar flares are referred to as solar energetic particles (SEPs) (Reames, 1999). Diffuse aurora is strongly correlated with SEP events. ICME-accelerated SEPs travel nearly radially, as opposed to flare-accelerated SEPs which follow the Parker spiral. If the solar source region is identified, ICME-accelerated SEP events at Mars, and thus diffuse aurora, can be forecasted. The dynamic nature of rover planning and operations allows for a reactive observation strategy that takes advantage of such forecasts. We made several attempts, starting in May 2023, to react to SEP events and observe with the M2020 rover (Farley et al., 2020) instruments at times when we believed the likelihood of emission to be highest. Our fourth attempt, in March 2024, yielded the positive detection reported here.
Acceso Abierto
Hexagonal Prisms Form in Water-Ice Clouds on Mars, Producing Halo Displays Seen by Perseverance Rover
(AGU Advancing Earth and Space Science, 2022-10-03) Lemmon, M. T.; Toledo, D.; Apéstigue, Víctor; Arruego, Ignacio; Wolff, Michael; Patel, P.; Guzewich, Scott; Colaprete, A.; Vicente Retortillo, Álvaro; Tamppari, L. K.; Montmessin, F.; De la Torre Juárez, M.; Maki, Justin N.; McConnochie, Timothy; Brown, Adrian Jon; Bell, James; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Ciencia e Innovación (MICINN); NASA Jet Propulsion Laboratory (JPL); Arizona State University (ASU); Ministerio de Economía y Competitividad (MINECO); Gobierno Vasco; European Research Council (ERC); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Observations by several cameras on the Perseverance rover showed a 22° scattering halo around the Sun over several hours during northern midsummer (solar longitude 142°). Such a halo has not previously been seen beyond Earth. The halo occurred during the aphelion cloud belt season and the cloudiest time yet observed from the Perseverance site. The halo required crystalline water-ice cloud particles in the form of hexagonal columns large enough for refraction to be significant, at least 11 μm in diameter and length. From a possible 40–50 km altitude, and over the 3.3 hr duration of the halo, particles could have fallen 3–12 km, causing downward transport of water and dust. Halo-forming clouds are likely rare due to the high supersaturation of water that is required but may be more common in northern subtropical regions during northern midsummer.
Acceso Abierto
Seasonal Variations in Atmospheric Composition as Measured in Gale Crater, Mars
(American Geophysical Union: Advancing Earth and Space Science, 2019-11-12) Trainer, M. G.; Wong, Michael H.; McConnochie, Timothy; Franz, H. B.; Atreya, S. K.; Conrad, Pamela G.; Lefèvre, F.; Mahaffy, Paul R.; Malespin, C. A.; Manning, H. L. K.; Martín Torres, Javier; Martínez, Germán M.; McKay, Christopher P.; Navarro González, R.; Vicente Retortillo, Álvaro; Webster, Christopher R.; Zorzano, María-Paz; Universidad Nacional Autónoma de México (UNAM); Zorzano, M. P. [0000-0002-4492-9650]; Navarro González, R. [0000-0002-6078-7621]; Martín Torres, J. [0000-0001-6479-2236]; Vicente Retortillo, A. [0000-0002-4553-7624]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Sample Analysis at Mars (SAM) instrument onboard the Mars Science Laboratory Curiosity rover measures the chemical composition of major atmospheric species (CO2, N2, 40Ar, O2, and CO) through a dedicated atmospheric inlet. We report here measurements of volume mixing ratios in Gale Crater using the SAM quadrupole mass spectrometer, obtained over a period of nearly 5 years (3 Mars years) from landing. The observation period spans the northern summer of MY 31 and solar longitude (LS) of 175° through spring of MY 34, LS = 12°. This work expands upon prior reports of the mixing ratios measured by SAM QMS in the first 105 sols of the mission. The SAM QMS atmospheric measurements were taken periodically, with a cumulative coverage of four or five experiments per season on Mars. Major observations include the seasonal cycle of CO2, N2, and Ar, which lags approximately 20–40° of LS behind the pressure cycle driven by CO2 condensation and sublimation from the winter poles. This seasonal cycle indicates that transport occurs on faster timescales than mixing. The mixing ratio of O2 shows significant seasonal and interannual variability, suggesting an unknown atmospheric or surface process at work. The O2 measurements are compared to several parameters, including dust optical depth and trace CH4 measurements by Curiosity. We derive annual mean volume mixing ratios for the atmosphere in Gale Crater: CO2 = 0.951 (±0.003), N2 = 0.0259 (±0.0006), 40Ar = 0.0194 (±0.0004), O2 = 1.61 (±0.09) x 10‐3, and CO = 5.8 (±0.8) x 10‐4.
Acceso Abierto
Surface Energy Budget, Albedo, and Thermal Inertia at Jezero Crater, Mars, as Observed From the Mars 2020 MEDA Instrument
(AGU Advancing Earth and Space Science, 2023-02) Martínez, Germán M.; Sebastián, E.; Vicente Retortillo, Álvaro; Smith, Michael D.; Johnson, J. R.; Fischer, E.; Savijärvi, H.; Toledo, D.; Hueso, R.; Mora Sotomayor, L.; Gillespie, H.; Munguira, A.; Sánchez Lavega, Agustín; Lemmon, M. T.; Gómez, Felipe; Polkko, J.; Mandon, Lucía; Apéstigue, Víctor; Arruego, Ignacio; Ramos, Miguel; Conrad, Pamela G.; Newman, C. E.; De la Torre Juárez, M.; Jordan, Francisco; Tamppari, L. K.; McConnochie, Timothy; Harri, Ari-Matti; Genzer, María; Hieta, M.; Zorzano, María-Paz; Siegler, M.; Prieto-Ballesteros, Olga; Molina, A.; Rodríguez Manfredi, J. A.; Comunidad de Madrid; Universities Space Research Association (USRA); Agencia Estatal de Investigación (AEI); Gobierno Vasco; Instituto Nacional de Técnica Aeroespacial (INTA); Centre National D'Etudes Spatiales (CNES); National Aeronautics and Space Administration (NASA); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Mars Environmental Dynamics Analyzer (MEDA) on board Perseverance includes first-of-its-kind sensors measuring the incident and reflected solar flux, the downwelling atmospheric IR flux, and the upwelling IR flux emitted by the surface. We use these measurements for the first 350 sols of the Mars 2020 mission (Ls ∼ 6°–174° in Martian Year 36) to determine the surface radiative budget on Mars and to calculate the broadband albedo (0.3–3 μm) as a function of the illumination and viewing geometry. Together with MEDA measurements of ground temperature, we calculate the thermal inertia for homogeneous terrains without the need for numerical thermal models. We found that (a) the observed downwelling atmospheric IR flux is significantly lower than the model predictions. This is likely caused by the strong diurnal variation in aerosol opacity measured by MEDA, which is not accounted for by numerical models. (b) The albedo presents a marked non-Lambertian behavior, with lowest values near noon and highest values corresponding to low phase angles (i.e., Sun behind the observer). (c) Thermal inertia values ranged between 180 (sand dune) and 605 (bedrock-dominated material) SI units. (d) Averages of albedo and thermal inertia (spatial resolution of ∼3–4 m2) along Perseverance's traverse are in very good agreement with collocated retrievals of thermal inertia from Thermal Emission Imaging System (spatial resolution of 100 m per pixel) and of bolometric albedo in the 0.25–2.9 μm range from (spatial resolution of ∼300 km2). The results presented here are important to validate model predictions and provide ground-truth to orbital measurements.
Acceso Abierto
The dynamic atmospheric and aeolian environment of Jezero crater, Mars
(Science Publishin Group, 2022-05-25) Newman, C. E.; Hueso, R.; Lemmon, M. T.; Munguira, A.; Vicente Retortillo, Álvaro; Apéstigue, Víctor; Martínez, Germán M.; Toledo, D.; Sullivan, Robert; Herkenhoff, K. E.; De la Torre Juárez, M.; Richardson, M. I.; Stott, A.; Murdoch, N.; Sánchez Lavega, Agustín; Wolff, Michael; Arruego, Ignacio; Sebastián, E.; Navarro López, Sara; Gómez Elvira, J.; Tamppari, L. K.; Smith, Michael D.; Lepinette Malvitte, A.; Viúdez Moreiras, Daniel; Harri, Ari-Matti; Genzer, María; Hieta, M.; Lorenz, R. D.; Conrad, Pamela G.; Gómez, Felipe; McConnochie, Timothy; Mimoun, D.; Tate, C.; Bertrand, T.; Belli, J. F.; Maki, Justin N.; Rodríguez Manfredi, J. A.; Wiens, Roger; Chide, B.; Maurice, Sylvestre; Zorzano, María-Paz; Mora Sotomayor, L.; Baker, M. M.; Banfield, D.; Pla García, J.; Beyssac, O.; Brown, Adrian Jon; Clark, B.; Montmessin, F.; Fischer, E.; Patel, P.; Del Río Gaztelurrutia, T.; Fouchet, T.; Francis, Raymond; Guzewich, Scott; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Ciencia e Innovación (MICINN); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Gobierno Vasco; National Aeronautics and Space Administration (NASA); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Despite the importance of sand and dust to Mars geomorphology, weather, and exploration, the processes that move sand and that raise dust to maintain Mars’ ubiquitous dust haze and to produce dust storms have not been well quantified in situ, with missions lacking either the necessary sensors or a sufficiently active aeolian environment. Perseverance rover’s novel environmental sensors and Jezero crater’s dusty environment remedy this. In Perseverance’s first 216 sols, four convective vortices raised dust locally, while, on average, four passed the rover daily, over 25% of which were significantly dusty (“dust devils”). More rarely, dust lifting by nonvortex wind gusts was produced by daytime convection cells advected over the crater by strong regional daytime upslope winds, which also control aeolian surface features. One such event covered 10 times more area than the largest dust devil, suggesting that dust devils and wind gusts could raise equal amounts of dust under nonstorm conditions.