Tuesday, March 15, 2011

LROC PDS Release Number 5

LROC Wide Angle Camera (WAC) mosaic centered on Orientale basin. From the center of the mosaic to a corner is about 2000 km. View the full LROC 1600 x 1600 Featured Image HERE [NASA/GSFC/Arizona State University].

Mark Robinson
Principal Investigator
Lunar Reconnaissance Orbiter Camera (LROC)
Arizona State University

The 5th LROC Planetary Data System (PDS) release includes images acquired between September 16, 2010 and December 15, 2010, during the Science mission phase. This release includes 69,505 Experiment Data Record (EDR) images totaling 8,498 Gbytes and 69,528 Calibrated Data Record (CDR) images totaling 17,651 Gbytes worth of data.

The LROC Team is also making it's first Reduced Data Record (RDR) release this week, which represents a culmination of many months of work calibrating, map projecting, and creating mosaics and topographic maps from NAC and WAC images. The RDR release includes a global WAC monochrome mosaic, NAC mosaics for 40 regions of interest (ROI), numerous NAC DTM products, NAC North and South Polar mosaics, several example WAC UV and VIS regional mosaics, and over 8,000 WAC North and South Pole observations used to create movies of each poles lighting conditions over time. The RDR release totals over 8,400 images totaling over 2 Tbytes of data.

At full-resolution, zooming in on the Orientale pyroclastic vent perched at the center of a dark "smoke ring," of darker material draped upon the mountainous southwestern edge of the Orientale basin. The vent interior has already been imaged in great detail by the LROC Narrow Angle Camera, but the WAC mosaics deliver unprecedented context and depth of field [NASA/GSFC/Arizona State University].

Today's Featured Image is an orthographic re-projection of the WAC global mosaic centered on the youngest large basin on the Moon, Orientale. This basin is barely visible on the western limb of the Moon as seen from the Earth. Its existence was not confirmed until spacecraft sent back images of the farside 50 years ago. Unlike other large basins, Orientale has very little volcanic materials filling its interior, so the basin structure is easily seen. The inner and outer basin rings are particularly obvious - imagine if the Moon were rotated 90° and the Orientale basin faced the Earth. What sort of mythology would have grown up around the great eyeball in the sky?

Backing away, the vent is harder to discern, though the ring of darker material surrounding it makes the feature easier to pick out. Compare this with the high-sun incidence view further below taken from Galileo on its way toward Jupiter in 1990 [NASA/GSFC/Arizona State University].

The new WAC Orientale mosaic also reveals striking detail in the far-flung ejecta blanket. Note the radial chains of secondary craters formed as large chunks of the Moon were thrown hundreds of kilometers! These same type of large impacts occurred on the Earth also - fortunately the era of heavy bombardment ended about 3.9 billion years ago!

Explore the Orientale basin at 100 m/pixel.

Revisit the early version of the WAC Orientale mosaic.

Early in the Galileo mission to Jupiter, the probe used Earth's Moon to test and baseline it's remote sensing capabilities. During a second gravity-assist fly-by of the Earth-Moon system in 1990, JPL turned the probe's cameras on the Moon's western hemisphere and swept up this late morning overhead view of Mare Orientale [NASA/JPL].

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