26 April 2019

Sols 2390-2393: Confirmation of another taste of the "Clay-Bearing Unit", as good as the first?

Posted by Ryan Anderson

Navcam Right image showing the newest ‘Kilmarie’ drill hole on the right, less than 1 meter away from the ‘Aberlady’ drill hole on the left.

We started planning in eager anticipation of the preliminary results from our downlink and whether the CheMin X-ray diffraction spectrometer received enough sample of the ‘Kilmarie’ drill sample to successfully complete a first night of analysis. Less than 40 minutes after downlink, we got confirmation from the CheMin team that they did indeed receive enough material. This meant that we could proceed with the two highest priority activities in the plan; the second night of CheMin analysis of the Kilmarie drill sample, and a SAM preconditioning activity in preparation for delivery of sample for a SAM Evolved Gas Analysis (EGA) experiment in the coming week’s plan. The CheMin instrument informs us of the mineralogy of the sample, which can give us clues about the source of the rock sample, the conditions under which it formed and any subsequent alteration events. It will be interesting to compare the mineralogy of Kilmarie with the nearby ‘Aberlady’ drill hole. The SAM EGA experiment will measure the composition of the different gases evolved at different temperatures as the sample is heated in the SAM oven. This complements the CheMin data and can help refine the mineralogy and tell us about the amount and nature of S, N, H, Cl, O and C associated with the various minerals. We are particularly interested in whether this sample from the ‘Clay-Bearing Unit,’ Glen Torridon area, does in fact contain clay (as have the majority of drilled samples), and if it does, how much is present and what type of clay mineral is it?

The science team also planned ChemCam LIBS on four rock targets (‘Mile End,’ ‘Tillyfourie,’ ‘Tillybrachty’ and ‘Tillymorgan’) in the vicinity of the drill hole to continue to monitor compositional variation between relatively coherent and more rubbly bedrock that we have been observing within Glen Torridon. We will also acquire Mastcam support imaging for the ChemCam targets as well as a large multispectral mosaic in the direction of the ‘Greenheugh Pediment’ and ‘Sulfate-Bearing Unit’ that we will eventually drive to. The multispectral mosaic will help to highlight possible spectral and mineralogical differences between the different coloured strata we observe in this area.

Today was also a busy planning day for environmental observations with three science blocks devoted to these activities. A ChemCam passive sky measurement was included to look at water vapour and aerosols in the atmosphere above Curiosity, as well as Mastcam tau observations to measure the atmospheric opacity and a large Navcam dust devil survey. Navcam zenith observations were also planned as part of the ongoing campaign to monitor martian clouds. Standard background REMS activities monitor the daily martian weather and we continue to monitor the radiation environment with RAD and the abundance and distribution of H- and OH-bearing materials within the subsurface with DAN passive activities.

As the APXS strategic planner tosol, I have been able to focus on monitoring all of the other science activities taking place to write this blog, as there was no APXS. We have to wait to use the arm, and MAHLI and APXS on the end of the arm, until after we have dumped the Kilmarie drill fines from the drill bit assembly. This does not occur until the SAM and CheMin instrument teams confirm that they do not require any more sample.Both the MAHLI and APXS teams eagerly await the chance to analyze the drill fines from this latest hole on Mars.

Written by Lucy Thompson, Planetary Geologist at University of New Brunswick