Geology topics

Patricio Becerra

Publications and source records attributed to Patricio Becerra.

7 recordsLinked to original sources

USGS2024

Polar science results from Mars Reconnaissance Orbiter: Multiwavelength, multiyear insights

Mars Reconnaissance Orbiter (MRO), with its arrival in 2006 and nearly continuous operation since, has provided data for the study of martian polar processes spanning nine Mars years. Mars' polar deposits have long been thought to preserve records of past climates, potentially readable like terrestrial ice cores. However, unraveling millions of years of history in the ice depends on understanding Mars' current and recent-past climate, including the interactions of atmospheric and surface processes . MRO has allowed for revolutionary discoveries, long-term monitoring of ongoing processes, and multiple complementary datasets to address the question of how the polar ice deposits reflect climatological changes. In part, MRO has been able to do this from its variety of instrumentation simultaneously observing interannual changes in geomorphology of the surface in up to ∼25 cm/pixel detail, repeatable processes and changes in the atmosphere, and surface composition, as well as investigating signs of past changes recorded in the icy polar layered deposits. In this paper, we summarize the contribution of MRO to our current understanding of Mars polar science, and in particular how MRO's long-duration mission has improved our understanding of the fundamental volatile cycles on Mars.

Icarus↗

USGS2021

Past, present, and future of Mars Polar Science: Outcomes and outlook from the 7th International Conference on Mars Polar Science and Exploration

Mars Polar Science is a subfield of Mars science that encompasses all studies of the cryosphere of Mars and its interaction with the Martian environment. Every 4 yr, the community of scientists dedicated to this subfield meets to discuss new findings and debate open issues in the International Conference on Mars Polar Science and Exploration (ICMPSE). This paper summarizes the proceedings of the seventh ICMPSE and the progress made since the sixth edition. We highlight the most important advances and present the most salient open questions in the field today, as discussed and agreed upon by the participants of the conference. We also feature agreed-upon suggestions for future methods, measurements, instruments, and missions that would be essential to answering the main open questions presented. This work is thus an overview of the current status of Mars Polar Science and is intended to serve as a road map for the direction of the field during the next 4 yr and beyond, helping to shape its contribution within the larger context of planetary science and exploration.

The Planetary Science Journal↗

USGS2021

Active Mars: A dynamic world

Mars exhibits diverse surface changes at all latitudes and all seasons. Active processes include impact cratering, aeolian sand and dust transport, a variety of slope processes, changes in polar ices, and diverse effects of seasonal CO 2 frost. The extent of surface change has been surprising and indicates that the present climate is capable of reshaping the surface. Activity has important implications for the Amazonian history of Mars: understanding processes is a necessary step before we can understand their implications and variations over time.

Journal of Geophysical Research: Planets↗

USGS2021

Mid-latitude ice on Mars: A science target for planetary climate histories and an exploration target for in situ resources

In the last decade, aided by the high-resolution data and long-term monitoring by NASA’s Mars Reconnaissance Orbiter (MRO) and other spacecraft, extensive evidence has emerged supporting the presence of abundant H2O ground ice throughout much of the mid-latitudes of Mars. Growing evidence indicates that much of this ice is relatively pure, exists within a few meters of the surface, and reaches lower latitudes than previously thought, potentially providing an accessible record of the recent climate and a large in situ resource for future human exploration of Mars. We are reaching the limits of currently available datasets, however, just as we are starting to unlock the climate record and determine the water resources contained within the Martian mid-latitudes. A comprehensive understanding of the nature of this ice would significantly enhance our understanding of Mars’ climate history and total water budget, as well as the effects of orbital/axial forcing on volatiles. In this regard, Mars is a testbed for comparative planetary climate studies, including for exoplanets; these studies are particularly valuable because Mars has many similarities to Earth but lacks the complicating effects of oceans and a biosphere, such that orbital/axial forcing dominates climate variability. Quantifying the volumes, distribution, and properties of the water ice are crucial for addressing two overarching questions in the next decade: 1. What climate record is preserved in mid-latitude ice deposits on Mars? 2. How accessible is the ice as a resource for future exploration? New missions will enable us to capitalize on the major discoveries of the last decade and take the next giant leap in the upcoming decade to address these questions.

Bulletin of the AAS↗

USGS2018

6th international conference on Mars polar science and exploration: Conference summary and five top questions

We provide a historical context of the International Conference on Mars Polar Science and Exploration and summarize the proceedings from the 6th iteration of this meeting. In particular, we identify five key Mars polar science questions based primarily on presentations and discussions at the conference and discuss the overlap between some of those questions. We briefly describe the seven scientific field trips that were offered at the conference, which greatly supplemented conference discussion of Mars polar processes and landforms. We end with suggestions for measurements, modeling, and laboratory and field work that were highlighted during conference discussion as necessary steps to address key knowledge gaps.

Icarus↗

USGS2017

Image simulation and assessment of the colour and spatial capabilities of the Colour and Stereo Surface Imaging System (CaSSIS) on the ExoMars Trace Gas Orbiter

This study aims to assess the spatial and visible/near-infrared (VNIR) colour/spectral capabilities of the 4-band Colour and Stereo Surface Imaging System (CaSSIS) aboard the ExoMars 2016 Trace Grace Orbiter (TGO). The instrument response functions for the CaSSIS imager was used to resample spectral libraries, modelled spectra and to construct spectrally ( i.e. , in I/F space) and spatially consistent simulated CaSSIS image cubes of various key sites of interest and for ongoing scientific investigations on Mars. Coordinated datasets from Mars Reconnaissance Orbiter (MRO) are ideal, and specifically used for simulating CaSSIS. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) provides colour information, while the Context Imager (CTX), and in a few cases the High-Resolution Imaging Science Experiment (HiRISE), provides the complementary spatial information at the resampled CaSSIS unbinned/unsummed pixel resolution (4.6 m/pixel from a 400-km altitude). The methodology used herein employs a Gram-Schmidt spectral sharpening algorithm to combine the ∼18–36 m/pixel CRISM-derived CaSSIS colours with I/F images primarily derived from oversampled CTX images. One hundred and eighty-one simulated CaSSIS 4-colour image cubes (at 18–36 m/pixel) were generated (including one of Phobos) based on CRISM data. From these, thirty-three “fully”-simulated image cubes of thirty unique locations on Mars ( i.e. , with 4 colour bands at 4.6 m/pixel) were made. All simulated image cubes were used to test both the colour capabilities of CaSSIS by producing standard colour RGB images, colour band ratio composites (CBRCs) and spectral parameters. Simulated CaSSIS CBRCs demonstrated that CaSSIS will be able to readily isolate signatures related to ferrous (Fe 2+ ) iron- and ferric (Fe 3+ ) iron-bearing deposits on the surface of Mars, ices and atmospheric phenomena. Despite the lower spatial resolution of CaSSIS when compared to HiRISE, the results of this work demonstrate that CaSSIS will not only compliment HiRISE-scale studies of various geological and seasonal phenomena, it will also enhance them by providing additional colour and geologic context through its wider and longer full-colour coverage ( ∼ 9.4 × 50 "> ∼ 9.4 × 50 ∼9.4×50 km), and its increased sensitivity to iron-bearing materials from its two IR bands (RED and NIR). In a few examples, subtle surface changes that were not easily detected by HiRISE were identified in the simulated CaSSIS images. This study also demonstrates the utility of the Gram-Schmidt spectral pan-sharpening technique to extend VNIR colour/spectral capabilities from a lower spatial resolution colour/spectral dataset to a single-band or panchromatic image greyscale image with higher resolution. These higher resolution colour products (simulated CaSSIS or otherwise) are useful as means to extend both geologic context and mapping of datasets with coarser spatial resolutions. The results of this study indicate that the TGO mission objectives, as well as the instrument-specific mission objectives, will be achievable with CaSSIS.

Space Science Reviews↗

USGS2016

Stratigraphy of the north polar layered deposits of Mars from high-resolution topography

The stratigraphy of the layered deposits of the polar regions of Mars is theorized to contain a record of recent climate change linked to insolation changes driven by variations in the planet's orbital and rotational parameters. In order to confidently link stratigraphic signals to insolation periodicities, a description of the stratigraphy is required based on quantities that directly relate to intrinsic properties of the layers. We use stereo Digital Terrain Models (DTMs) from the High Resolution Imaging Science Experiment (HiRISE) to derive a characteristic of North Polar Layered Deposits (NPLD) strata that can be correlated over large distances: the topographic protrusion of layers exposed in troughs, which is a proxy for the layers’ resistance to erosion. Using a combination of image analysis and a signal-matching algorithm to correlate continuous depth-protrusion signals taken from DTMs at different locations, we construct a stratigraphic column that describes the upper ~500 m of at least 7% of the area of the NPLD, and find accumulation rates that vary by factors of up to two. We find that, when coupled with observations of exposed layers in orbital images, the topographic expression of the strata is consistently continuous through large distances in the top 300 – 500 m of the NPLD, suggesting it is better related to intrinsic layer properties than brightness alone.

Journal of Geophysical Research E: Planets↗