As we describe below, every pixel can be traced to its host orbit through vectorized seam-maps that are provided with every tile. The planet was divided into 3,960 4°x4° tiles and blended independently, then blended together to complete the mosaic. All data are resampled to 5.0 m/px in an equirectangular projection. Orbits not included were either (1) low signal/noise (increased atmospheric opacity), or (2) redundant coverage (stereo targets, change detection, etc.). The mosaic is comprised of 86,571 separate CTX images out of 104,647 available. Sporadic images subsequent to release 49 (up to mission phase N08, July 2020) were used to fill unusually large gaps in the mosaic. The Global CTX Mosaic was constructed using all CTX data through MRO release 49, CTX mission phase K11 (December 1, 2018). Gaps in coverage (0.5% of the planet) are shown as white strips. For scientific and technical overviews of the CTX instrument, please see Malin et al. When using these data in a publication, presentation or poster, please acknowledge the hard work of the scientists and engineers at Malin Space Science Systems and the Jet Propulsion Laboratory. This version of the mosaic is the successor to the Beta01 version, which is still available here. This connects the mosaic directly with its original data, ensures that blending artifacts are not mistaken for landforms and geologic contacts, and provides instant access to the raw data that comprise the mosaic. We have developed a Python-based pipeline that incorporates non-destructive image processing techniques that preserve all information about the original data that comprise the mosaic and map all seams. We emphasize transparency both in how the mosaic was generated and for users to understand where data in the mosaic come from. Until then, the most recent description of this product is from the 2023 Lunar and Planetary Science Conference. We are currently preparing a manuscript for peer-review. We provide details of the full data processing pipeline below. Overlapping images were registered to each other (semi-controlled) before blending. "Assessment of antipodal-impact terrains on Mars." Icarus 110.2 (1994): 196-202.The V01 release of the Global CTX Mosaic is comprised of 86,571 separate images acquired between 20. "Antipodal effects of major basin-forming impacts on Mars." Lunar and Planetary Science Conference. "Alba Patera, Mars: Topography, structure, and evolution of a unique late Hesperian–early Amazonian shield volcano." Journal of Geophysical Research: Planets 111.E9 (2006). "Geologic history of Mars." Earth and Planetary Science Letters 294.3-4 (2010): 185-203. It formed at least 200 million years after the Hellas Basin impact and perhaps as much as a billion years after (Ivanov 2006).īottom line: If the huge impact that formed the Hellas Basin did have any antipodal effects, those effects are buried under the magma that formed Alba Mons several hundred million years later.Ĭarr, Michael H., and James W. Alba Mons, while also quite old, isn't that old. Based on crater density, the Hellas Basin appears to be very old, at least 3.8 billion years old (Carr 2010). Improved remote observations of Mars has provided a tool for estimating ages of Mars features: crater density. There's an issue with this hypothesis, which is that the apparent ages do not align. Both Peterson and Williams suggested that the Hellas Basin impact might well have triggered the vulcanism that resulted in Alba Mons. This shield volcano is a bit to the north of the Tharsis Rise proper, and well to the north of the Tharsis Montes. The shield volcano Alba Mons however is almost exactly antipodal to the Hellas Basin. ![]() The Tharsis Montes themselves are far too close to the equator to be considered antipodal to the Hellas Basin. You were not the first to have seen that the Hellas Basin and parts of the Tharsis Rise are roughly antipodal (Peterson 1978, Williams and Greeley 1994). Are Tharsis Montes and Hellas Basin a result of the same event?
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