Browsing by Author "Mazarico, Erwan"
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Item Constraining the Venus Interior Structure with Future VERITAS Measurements of the Gravitational Atmospheric Loading(IOP, 2023-04-12) Cascioli, Gael; Renaud, Joe P.; Mazarico, Erwan; Durante, Daniele; Iess, Luciano; Goossens, Sander; Smrekar, SuzanneThe complex dynamics of the Venus atmosphere produces a periodic mass redistribution pattern that creates a time-variable modulation of the gravity field of Venus. This gravity signal depends on the net transport of mass across the globe and on the response of the solid body to the normal loading of its crust imparted by the atmosphere. In this work, we explore the possibility of measuring this phenomenon with VERITAS, a NASA Discovery-class mission. By simulating the gravity science experiment, we explore the possibility of measuring the response of Venus to the atmospheric loading, parametrized by the loading Love numbers (𝘬ₗ'), and assess the dependence of these parameters on fundamental interior structure properties. Using the most recent models of Venus' interior, we compute the Venus Love numbers in a compressible viscoelastic setting and compare them with the predicted uncertainty of the VERITAS measurements. We show that VERITAS will measure 𝘬₂' at the 4% level and that this measurement could possibly help to distinguish between different equally plausible interior structure models, especially allowing us to distinguish different rheological laws. We also show that a measurement campaign such as the VERITAS gravity science investigation has the potential of measuring 𝘬₂' not only at the loading forcing frequency, but also at the tidal frequency, ultimately providing a way to probe the response of the planet at different forcing periods.Item The Contribution of Small Impact Craters to Lunar Polar Wander(IOP, 2022-09-19) Smith, David E.; Viswanathan, Vishnu; Mazarico, Erwan; Goossens, Sander; Head, James W.; Neumann, Gregory A.; Zuber, Maria T.Changes in mass distribution affect the gravitational figure and reorient a planetary body’s surface with respect to its rotational axis. The mass anomalies in the present-day lunar gravity field can reveal how the figure and pole position have evolved over the Moon’s history. By examining sequentially each individual crater and basin, working backward in time order through the catalog of nearly 5200 craters and basins between 1200 and 20 km in diameter, we investigate their contribution to the lunar gravitational figure and reconstruct the evolution of the pole position by extracting their gravitational signatures from the present-day Moon. We find that craters and basins in this diameter range, which excludes South Pole–Aitken, have contributed to nearly 25% of the present-day power from the Moon’s degree-2 gravitational figure and resulted in a total displacement of the Moon’s pole by ∼10° along the Earth–Moon tidal axis over the past ∼4.25 billion years. This also implies that the geographical location of the Moon’s rotational pole has not moved since ∼3.8 Ga by more than ∼2° in latitude owing to impacts, and this has implications for the long-term stability of volatiles in the polar regionsItem Exploring the Venus Crust and Lithosphere with the VERITAS Gravity Science Investigation(2023) Mazarico, Erwan; Iess, Luciano; Cascioli, Gael; Durante, Daniele; De Marchi, Fabrizio; Hensley, Scott; Smrekar, SuzanneItem Extending Science from Lunar Laser Ranging(2020-08-21) Viswanathan, Vishnu; Mazarico, Erwan; Merkowitz, Stephen; Williams, James G.; Turyshev, Slava G.; Currie, Douglas G.; Ermakov, Anton I.; Rambaux, Nicolas; Fienga, Agnès; Courde, Clément; Chabé, Julien; Torre, Jean-Marie; Bourgoin, Adrien; Schreiber, Ulrich; Eubanks, Thomas M.; Wu, Chensheng; Dequal, Daniele; Agnello, Simone Dell; Biskupek, Liliane; Müller, Jürgen; Kopeikin, SergeiThe Lunar Laser Ranging (LLR) experiment has accumulated 50 years of range data of improving accuracy from ground stations to the laser retroreflector arrays (LRAs) on the lunar surface. The upcoming decade offers several opportunities to break new ground in data precision through the deployment of the next generation of single corner-cube lunar retroreflectors and active laser transponders. This is likely to expand the LLR station network. Lunar dynamical models and analysis tools have the potential to improve and fully exploit the long temporal baseline and precision allowed by millimetric LLR data. Some of the model limitations are outlined for future efforts. Differential observation techniques will help mitigate some of the primary limiting factors and reach unprecedented accuracy. Such observations and techniques may enable the detection of several subtle signatures required to understand the dynamics of the Earth-Moon system and the deep lunar interior. LLR model improvements would impact multi-disciplinary fields that include lunar and planetary science, Earth science, fundamental physics, celestial mechanics and ephemerides.Item First two-way laser ranging to a lunar orbiter: infrared observations from the Grasse station to LRO’s retro-reflector array(Springer Nature, 2020-08-06) Mazarico, Erwan; Sun, Xiaoli; Torre, Jean-Marie; Courde, Clément; Chabé, Julien; Aimar, Mourad; Mariey, Hervé; Maurice, Nicolas; Barker, Michael K.; Mao, Dandan; Cremons, Daniel R.; Bouquillon, Sébastien; Carlucci, Teddy; Viswanathan, Vishnu; Lemoine, Frank G.; Bourgoin, Adrien; Exertier, Pierre; Neumann, Gregory A.; Zube, Maria T.; Smith, David E.We present the results of the first series of successful two-way laser ranging experiments from a ground station, the Lunar Laser Ranging (LLR) station in Grasse, France, to a spacecraft at lunar distance, the Lunar Reconnaissance Orbiter (LRO). A 15 × 18 × 5 cm, 650-g array of twelve 32-mm diameter solid corner cubes is mounted on its anti-nadir deck. Ranging to this small retro-reflector array onboard a lunar orbiter from a ground station was a challenge compared to ranging to larger lunar surface retro-reflectors. Grasse measured 67 returns in two 6-min sessions on September 4, 2018. Clear returns were also recorded during two additional sessions on August 23–24, 2019 for which active slewing by LRO was performed to bring the array in view of the station. The measured echos yielded range residuals less than 3 cm (two-way time-of-flight RMS < 180 ps) relative to the reconstructed LRO trajectory. This experiment provides a new method of verifying theories of dust accumulation over decades on the lunar surface. It also showed that the use of similar arrays onboard future lunar landers and orbiters can support LLR lunar science goals, particularly with landing sites near the lunar limbs and poles, which would have better sensitivity to lunar orientation.Item Highly Resolved Topography and Illumination at Mercury's South Pole from MESSENGER MDIS NAC(IOP, 2023-02-02) Bertone, Stefano; Mazarico, Erwan; Barker, Michael K.; Siegler, Matthew A.; Martinez-Camacho, Jose M.; Hamill, Colin D.; Glantzberg, Allison K.; Chabot, Nancy L.Mercury’s south polar region is of particular interest since Arecibo radar measurements show many highreflectance regions consistent with ice deposits. However, current elevation information in Mercury’s southern hemisphere is not sufficient to perform detailed modeling of the illumination and thermal conditions at these radarbright locations and to constrain properties of the volatiles potentially residing there. In this work, we leverage previously existing elevation maps of Mercury’s surface from stereo-photogrammetry at 665 m pix⁻¹ , Mercury Dual Imaging System Narrow Angle Camera images, and Shape-from-Shading tools from the Ames Stereo Pipeline, to provide the first high-resolution topographic maps of the south pole with a resolution of 250 m pix⁻¹ poleward of 75°S. We show that the increased resolution and level of detail provided by our new elevation model allow for a more realistic recovery of illumination conditions in Mercury’s south polar region, thus opening the way to future thermal analyses and for the characterization of potential ice and volatile deposits. We compare both the old and new topographic models to the Mercury Dual Imaging System Narrow Angle Camera images to show the higher level of fidelity with our products, and we assess the improved consistency of derived permanently shadowed regions with reflectance measurements by Arecibo’s antennas.Item Improving the VERITAS Orbit Reconstruction Using Radar Tie Points(American Institute of Aeronautics and Astronautics, 2022-11-27) Cascioli, Gael; Durante, Daniele; Mazarico, Erwan; Wallace, Mark; Hensley, Scott; Smrekar, SuzanneItem Mass and Shape Determination of (101955) Bennu Using Differenced Data from Multiple OSIRIS-REx Mission Phases(IOP Publishing, 2021-11-01) Goossens, Sander; Rowlands, David D.; Mazarico, Erwan; Liounis, Andrew J.; Small, Jeffrey L.; Highsmith, Dolan E.; Swenson, Jason C.; Lyzhoft, Joshua R.; Ashman, Benjamin W.; Getzandanner, Kenneth M.; Leonard, Jason M.; Geeraert, Jeroen L.; Adam, Coralie D.; Antreasian, Peter G.; Barnouin, Olivier S.; Daly, Michael G.; Seabrook, Jeffrey A.; Lauretta, Dante S.The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission collected a sample from the rubble-pile asteroid (101955) Bennu for return to Earth. For the successful Touch And Go sample acquisition maneuver, the shape and mass of the asteroid needed to be known precisely. Here we use a combination of radiometric, image landmark, and laser altimetry data to determine Bennu's mass, shape, and orientation simultaneously and to verify existing models thereof. Our shape determination consists of estimating a scale factor and three frame rotation angles that apply to both the global digital terrain model (GDTM) and the landmark coordinates. We use a data type called image constraints, where we take the difference of the observation of the same landmark in images taken at two different times. We analyze data from two phases of the OSIRIS-REx mission, Orbital B and Recon B, and show that interphase image constraints greatly reduce interdependencies between estimated parameters for mass, GDTM scale, and biases on the altimetry data. This results in an improved solution for the mass and shape relative to considering a single mission phase. We find Bennu's gravitational parameter GM to be 4.89256 ± 0.00035 m³ s⁻², and we find a scale factor of 1.000896 ± 0.00036 for the altimetry-based GDTM. Using the scaled volume, this results in a bulk density of 1191.57 ± 1.74 kg m⁻³ , which is within the uncertainties of previous analyses but more precise.Item Next-Generation Geodesy at the Lunar South Pole: An Opportunity Enabled by the Artemis III Crew(2020-09-08) Viswanathan, Vishnu; Mazarico, Erwan; Merkowitz, Stephen; Sun, Xiaoli; Eubanks, Thomas Marshall; Smith, David EdmundLunar retro-reflector arrays (LRAs) consisting of corner-cube reflectors (CCRs) placed on the nearside of the Moon during the Apollo era have demonstrated their longevity, cost-effectiveness, ease of deployment, and most importantly their interdisciplinary scientific impact through the ongoing lunar laser ranging (LLR) experiment. The human exploration of the lunar south polar region provides a unique opportunity to build on this legacy and contribute to the scientific return of the Artemis, for many decades to come. Here we outline the extended science objectives realizable with the deployment of geodetic tracking devices by the Artemis III crew.Item Testing the gravitational redshift during VERITAS cruise phase(2022-11-16) Marchi, Fabrizio De; Cascioli, Gael; Ely, Todd; Iess, Luciano; Burt, Eric A.; Hensley, Scott; Mazarico, ErwanThe NASA Discovery-class mission VERITAS, selected in June 2021, will be launched towards Venus in 2027. In addition to the science instrumentation that will build global foundational geophysical datasets, VERITAS proposed to conduct a technology demonstration for the Deep Space Atomic Clock (DSAC-2). A first DSAC successfully operated in low-Earth orbit for more than two years, demonstrated the trapped ion atomic clock technology, and established a new level of performance for clocks in space. DSAC-2 would have further improvements in size, power, and performance. It would host a 1×10-¹³ grade USO to produce a frequency output with short-term stability of less than 2×10-¹³/√T (where τ is the averaging time). In this work, we investigate the possibility of leveraging DSAC-2's frequency stability to measure possible discrepancies in the redshift predicted by General Relativity. With its capability of establishing a one-way downlink Doppler link with Earth stations, DSAC-2 would enable precise tests of the dependency of the redshift on the location and velocity of the spacecraft and the Earth, thus providing improved tests of the Local Lorentz Invariance and Local Position Invariance. We perform accurate simulations of the experiment that would take place during the VERITAS cruise phase. We consider different parametrizations of the possible violations of the General Relativity, different operational conditions, and a wide spectrum of expected measurement performance assumptions. We show that DSAC-2 onboard VERITAS would provide new and improved constraints with respect to the current knowledge.Item Testing the gravitational redshift with an inner Solar System probe: The VERITAS case(APS, 2023-03-13) Marchi, Fabrizio De; Cascioli, Gael; Ely, Todd; Iess, Luciano; Burt, Eric A.; Hensley, Scott; Mazarico, ErwanThe NASA Discovery-class mission VERITAS, selected in June 2021, will be launched toward Venus after 2027. In addition to the science instrumentation that will build global foundational geophysical datasets, VERITAS proposed to conduct a technology demonstration for the Deep Space Atomic Clock (DSAC-2). A first DSAC successfully operated in low-Earth orbit for more than two years, demonstrated the trapped ion atomic clock technology, and established a new level of performance for clocks in space. DSAC-2 would have further improvements in size, power, and performance. It would host a 1 × 10⁻¹³ grade USO to produce a frequency output with short-term stability of less than 2 × 10⁻¹³/ √τ (where τ is the averaging time). However, due to funding shortfalls, DSAC-2, had to be canceled. The initially foreseen presence of an atomic clock on board the probe, however, raised the question whether this kind of instrumentation could be useful not only for navigation and time transfer but also for fundamental physics tests. In this work, we consider the DSAC-2 atomic clock and VERITAS mission as a specific example to measure possible discrepancies in the redshift predicted by general relativity by using an atomic clock onboard an interplanetary spacecraft. In particular we investigate the possibility of measuring possible violations of the local Lorentz invariance and local position invariance principles. We perform accurate simulations of the experiment during the VERITAS cruise phase. We consider different parametrizations of the possible violations of the general relativity, different operational conditions, and several different assumptions on the expected measurement performance. We show that DSAC-2 onboard VERITAS would provide new and improved constraints with respect to the current knowledge. Our analysis shows the scientific value of atomic clocks like DSAC-2 hosted onboard interplanetary spacecraft.Item VERITAS gravity investigations: measuring Venus’ rotational state, moment of inertia, Love numbers, and atmospheric tides(EGU, 2023-04-23) Iess, Luciano; de Marchi, Fabrizio; Cascioli, Gael; Mazarico, Erwan; Renaud, Joseph; Durante, Daniele; Goossens, Sander; Smrekar, Suzanne