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Cake day: June 24th, 2023

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  • The current location is Serpentine Rapids in the upper right of the map (North is up)

    The route (shown in blue) that the agency’s Perseverance Mars rover is expected to take as it climbs up the western rim of Jezero Crater is superimposed on this image taken by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter.

    At upper right is “Serpentine Rapids,” the final geologic location of interest for the Perseverance science team before the rover begins its ascent. “Dox Castle” is a region the science team would like to explore during the rover’s ascent. Two of the first regions the science team wants study at the top of the crater are “Pico Turquino” and “Witch Hazel Hill.”

    Imagery from NASA’s Mars orbiters indicates that Pico Turquino contains ancient fractures that may have been caused by hydrothermal activity in the distant past. Orbital views of Witch Hazel show layered materials that likely date from a time when Mars had a very different climate than today. Those views have revealed light-toned bedrock similar to what was found at “Bright Angel,” the area where Perseverance recently discovered and sampled the “Cheyava Falls” rock, which exhibits chemical signatures and structures that could possibly have been formed by life billions of years ago when the area contained running water.

    The distance the rover will drive to get from Serpentine Rapids to the Aurora Park/Pico Turquino area is about 1.1 miles (1.8 kilometers); the change in elevation between the two locations is about 980 feet (300 meters). The distance covered to go from Aurora Park/Pico Turquino to Witch Hazel Hill is about 1.2 miles (2,000 meters) and the change in elevation is about 820 feet (250 meters).










  • OK - I hope I’m with you now? You’re looking for the total traverse distance to compare it with the point-to-point distance? Rather that the last drive distance which I gave you in my last reply?

    It’s also reported on the same table as “Distance: Total traverse” The current total traverse distance reported by JPL is 27.57 kilometers (17.13 mile). That value is the distance of the path followed by the rover, and is updated after every drive by JPL. The point to distance (from the rover’s current location to its landing spot is only: 8802.14 meters (8.802 kilometers or 28878.42 ft)

    There is a an anomaly in the data provided by JPL, but it is relatively small (percentage wise). When we add up all the individual drives reported by JPL the current total is about 130 meters more than the reported total traverse. I suspect that difference was from when they were performing ‘multi-sol drives’ on the approach to the delta, and a part of one drive got double reported.

    AFAIK - Individual drives and the total traverse distance account for the uphill and downhill drives (elevation changes) during each drive as they use data from the wheel revolutions etc, and the inertial measurement instruments that tracks every turn and change in elevation during each drive (That data is also provided on a separate JSON feed that shows the change in elevation at a bunch of points during every drive). I choose to only report the elevation at the beginning and the end of each the drive as well as the elevation change since landing to keep the data on one table.


  • They are both shown in the table. The drive distance is shown is the first line of the table, the point-to-point distance is shown in the last line of the table.

    This particular drive was almost a straight line, so there is very little difference between the actual drive path and the point-to-point distance.

    Often there is a much larger difference, e.g. when the rover has to traverse around difficult terrain, or when it’s Autonav gets confused by terrain.

    The actual distance of the drive path is reported by the rover at the end of each drive. I calculate the point-to-point distance (straight line) using the Easting (X) and Northing) (Y) co-ordinates reported by the rover at the end of the previous drive for beginning of the new drive, and the end of the new drive.

    Hope that helps :)