The purpose of this exercise was to monitor on-board vibrations felt by the rover during material processing operations when the entire 30 kilogram (66-pound) arm / turret combination is vibrated at high speed by a powerful motor system for several hours at a time. Images were taken of the sample by both the Navcam and Mastcam systems on delivery of the sample to the tray and after the arm / turret had been subjected to further vibration operations. These will allow mission team members to better understand how such vibrations may be affecting the systems and instruments on the rover.
Also on Sol 78, SAM took a further sniff of the Martian air, analysing its component gases with its Quadrupole Mass Spectrometer, while the REMS system continued to monitor local climatic conditions.
Surveys of the Rocknest area have also revealed an interesting rock formation, dubbed “Zephyr”. This appears to be composed of two different materials: a hard, slow-wearing outer material, and a less durable inner material which, when exposed, erodes to form a swirling pattern. As the softer material erodes faster than the harder material when exposed to the Martian wind, it also gives rise to odd surface features, one of which scientists have taken to calling “Stonehenge”.
Zephyr also become a target for ChemCam, which delivered a range of shots around the “Stonehenge” feature without actually hitting it, allowing scientists to obtain data on both the harder, outer material of the rock and the inner, softer material, confirming that each has a very distinct chemical signature from the other.
This rock area was also the site for ChemCam’s first “tunneling” operation, whereby the laser was locked-on to s single point on a rock and fired 600 times to effectively “drill” a hole into it. While the resultant hole was only one millimetre deep, the changing chemical composition of the plasma generated by the repeated laser hits, as measured by ChemCam’s telescope / spectrometer, revealed how the chemical composition of the rock changed with depth far more accurately than could otherwise be achieved. This work helps determine which targets within the Rocknest area may be worth closer examination with other instruments prior to Curiosity resuming its journey to Glenelg.
Glenelg, the region Curiosity is heading towards, is so-named primarily for two reasons: it is a palindrome, which reflects the fact that the rover is liable to pass through it twice, “coming and going”, and – more directly – it refers to a range of rock formations in the Canadian Northwest Territories to which the region on Mars bears a strong resemblance.
However, as I’ve covered previously in these reports, Glenelg is also a small village in Scotland (which just this week participated in a Google+ hangout with NASA personnel and Curiosity project team members).
I’ve also recently covered news that the rock dubbed “Jake Matijevic”, which was examined by Curiosity prior to it reaching Rocknest turned out to have an interesting lithology which also occurs here on Earth. The name of this lithology is “mugearite”, which is taken from the name of the place where it was first identified: Mugeary on the Isle of Skye.
Coincidentally, Mugeary just happens to be just 40 kilometres (25 miles) from the village of Glenelg!
All images courtesy of NASA/JPL
Congratulations, also, to NASA and SpaceX on the successful return to earth on October 28th of the Dragon resupply vehicle at the conclusion of its first official “operational” mission.