Yellowknife Bay, Mars
NASA's Mars Science Laboratory rover, named Curiosity, arrived at the low lying depression on December 17, 2012, 125 sols, or Martian days, into its 668-sol planned mission on the planet.
Primary mission goals of the Mars Science Laboratory were to assess the potential habitability of the planet and whether or not the Martian environment is, or has ever been, capable of supporting life.
[5] Previous observations of Gale Crater show that the strata exposed at Yellowknife Bay are most likely fan or down slope equivalents, such as lacustrine deposits.
Yellowknife Bay was chosen by the Mars Science Laboratory team as the first major site for exploration because the exposed strata was inferred to be a shallow fluvial-lacustrine deposit.
These aqueous environments are believed to preserve evidence of paleo-habitability and potentially, Earth-like microorganisms capable of breaking down rocks and minerals for energy, known as chemolithoautotrophs.
[9] Still, a more ideal location to search for evidence of life on Mars would have been a member exposed more recently, as few as a million years or less, so it could have been better preserved from the harsh surface radiation.
[14] Active erosion, attributed to both aeolian and fluvial events, has caused the Gillespie Lake Member to weather away, revealing the underlying Sheepbed layer and creating a topographic step observable in HiRISE images from the Mars Reconnaissance Orbiter.
The Gillespie Lake bed appears massive and is composed of poorly sorted, angular to well-rounded grains, which make up sheetlike sandstone basalt.
The CheMin XRD, Mastcam, Chemcam, alpha particle x-ray spectrometer (APXS), and the Mars Hand Lens Imager (MAHLI) were all used to obtain the most complete picture possible of the chemistry and mineralogy of the two samples, which were used to describe the region as a whole.
[16] Clay minerals are hydrous aluminum phyllosillicates and form only in the presence of water, further supporting the claim that an ancient crater lake once existed in this region.
