After our exploration of a boulder field last week, Perseverance is continuing the Upper Fan campaign. We have driven to Echo Creek, from which we also have a view of Belva Crater.
Along our journey, we have seen many interesting rocks. These include a lumpy rock that the team named “Blueberry Island”, seen in the above Mastcam-Z image (Sol 765). This rock may be a conglomerate (sedimentary) rock, ejecta that was blasted out in the impact that formed the nearby Belva Crater, a volcanic rock, or something else entirely. The team will analyze the data we collected to help understand the diversity of rocks on the upper fan.
At Echo Creek, we’re conducting both long distance and close-up measurements. Visible in the distance, Belva Crater has an interesting depth to diameter ratio compared to other Martian craters, as it is shallower than expected. The crater walls also appear to have been breached. Is the crater infilled, or were the rims eroded down? Were the crater walls breached by water, or ice? Our science team hopes to answer these questions by taking a closer look at the crater walls from our vantage point.
As for Echo Creek itself, we see in orbital imagery that the rocks are a brighter color than those surrounding them, and also that they exhibit an interesting polygonal fracturing pattern. These rocks may be similar to those that form the ‘marginal fractured unit’, which has a number of hypothesized origins ranging from sedimentary to volcanic. However, they could instead be the same kind of rock that we found at Tenby, known as the curvilinear unit. Our closer inspection of Echo Creek will help us to distinguish between these different hypotheses.
Whether the rocks at Echo Creek prove to be the same as those we’ve already seen, or something new, we are approaching the end of our Upper Fan campaign and will soon begin our exploration of the marginal units. As we climb up the fan, our horizons continue to expand. Having recently celebrated its first Martian birthday, Perseverance shows no signs of slowing down!