Degraded Crater in Bedrock (ESP_049938_1550) - Request submitted: November 11, 2016; Request scheduled: March 17, 2017; Request fulfilled: March 22, 2017. Unusual high-standing, hummocky bedrock type in contact with a ghost crater. The bedrock unit is at least superficially similar to other outcrops within Terra Sabaea. These outcrops appear to be embayed by surrounding flat-lying bedrock. However, in this location, it appears to stratigraphically overly the ghost crater. This observation would help constrain the stratigraphic relationship between this "embayed" unit and the surrounding bedrock.
Inverted Channels at Boundary of Highlands and Intercrater Plains (ESP_051257_1570) - Request submitted: March 23, 2017; Request scheduled: June 26, 2017; Request fulfilled: July 3, 2017. This image targets inverted channels located at the boundary between Noachian highlands and Noachian intercrater plains bedrock. These channels are 200-500m wide, implying substantial fluvial activity. High-resolution imagery of these channels will aid in characterizing the amount of fluvial activity responsible for their formation. This location is also one of the few places where evidence of sedimentary processes operating to form intercrater plains has been clearly preserved. Thus, a HiRISE observation here will help clarify the relationship between materials eroded off the highlands and intercrater plains bedrock.
Well-Exposed Stratigraphy in Crater Wall (Stereo images ESP_051757_1580; ESP_051902_1580) - Request submitted: June 22, 2017; Request scheduled: August 18, 2017; Request fulfilled: August 11, 2017. This observation primarily targets the rim of a 12km diameter crater located within a plain in the northern Hellas Basin. The eroded rim and floor of this crater appear to expose several stratigraphic units. The goal of this observation is to allow the construction of a high-resolution stratigraphic column for this plain. A stratigraphic column will aid in understanding the formation of this plain and others like it in the northern Hellas region by enabling first-order estimates of lithology and unit thickness. The southern third of this image footprint attempts to extend the stratigraphic column upsection by imaging a region of high-thermal inertia that appears to overlie the section exposed in the crater wall. High resolution morphology will also help understand why this region of high thermal inertia is only present within the center of the plain.
Stereo justification: Stereo imaging will assist with increasing the accuracy of the measured thickness of stratigraphic units in this region. This increased accuracy is most important on the low-relief plains, where assumptions about slope used to estimate unit thicknesses with single-image analysis may not be valid at small scales.
Inverted Channel and Potential Sedimentary Deposit in Hellas Region (ESP_052390_1580) - Request submitted: June 2, 2017; Request scheduled: September 18, 2017; Request fulfilled: September 29, 2017. This observation targets a channel system connecting two areas of high thermal inertia which may represent sedimentary deposits. The channel system has a braided appearance in multiple locations, implying a relatively high sediment flux. Additionally, the southern end of the channel appears to be filled with material from a large area of high thermal inertia. The color imaging capacities of HiRise should help determine whether the inverted channel deposits match those of the high thermal inertia unit. If so, the morphology of these inverted channel units will provide valuable information on the sediment flux into the high thermal inertia unit. In turn, volumetric estimates of the high thermal inertia units in comparison to this channel system will provide an estimate into the duration of fluvial activity in this region.
Small Channel with Potential Overbank Deposits (ESP_052747_1560) - Request submitted: September 12, 2017; Request scheduled: October 18, 2017; Request fulfilled: October 27, 2017. This observation targets a small channel located within high thermal inertia material located on the floor of a heavily degraded crater. The observation will be used to determine if the channel is causally linked to the high thermal inertia material. In addition, this observation will capture a complex range of bedrock surface morphologies located near this channel, which will aid in understanding the stratigraphic relationship to the low thermal inertia material that surrounds this channel.
Sinuous Ridges at Thermophysical Boundary (ESP_053670_1550) - Request submitted: September 12, 2017; Request scheduled: January 1, 2018; Request fulfilled: January 8, 2018. This observation targets a trio of sinuous ridges located at the contact between high and low thermal inertia material on the floor of a heavily degraded crater. These sinuous ridges may be inverted terrain features relating to a small drainage network that appears to have formed on the southern rim of the degraded crater. A key goal of this observation is to understand the relationship of the sinuous ridges to both low and high thermal inertia materials (i.e. do the ridges represent low thermal inertia material being transported onto the floor of the crater, remnants of fluvial features carrying what became high thermal inertia material onto the floor, or entirely unrelated features?).
Diverse Bedrock in Northern Hellas Planitia (ESP_054671_1600) - Request submitted: June 15, 2017; Request scheduled: March 21, 2018; Request fulfilled: March 26, 2018. This observation targets a region variable surface morphologies near the northern rim of the Hellas Basin. Importantly, this observation would capture the contact between a unit with apparent transverse aeolian ridges (TARs) and an underlying bright unit. This bright unit seems to be related to the TAR unit. All instances of the unit appear in craters sampling through the TAR unit, or at contacts between the TAR unit and a dark-toned unit. The key goal is to constrain the thickness of the bright-toned unit and study its morphology to constrain potential composition and formation modes.
Sinuous Light Tone Surface on Ridged Plain (ESP_054748_1735) - April 3, 2019 HiRise Picture of the Day! - Request submitted: September 15, 2017; Request scheduled: March 27, 2018; Request fulfilled: April 1, 2018. This observation targets a light toned surface with a sinuous trace visible in CTX image D22_035654_1737_XN_06S242W. Broken segments of this trace can be followed back to highlands valley networks to the SE. This suggests a potential relationship between this feature and drainage from the highlands valley network. High resolution imagery of the light toned surface's morphology will aid in understanding its formation and relationship to the surrounding bedrock.