urn:nasa:pds:izenberg_pdart14_meap:data_tnmap:thermal_neutron_map 1.0 1.7.0.0 Product_Observational 2017-02-09 1.0 Peer reviewed version of the Izenberg PDART 2014 MEAP Thermal Neutron Map Product 2004-08-13Z 2015-04-30Z Science Derived MESSENGER Gamma-Ray Spectrometer (GRS) Anti-Coincidence Shield (ACS) data have been used to map variations in thermal neutron absorbing elements across Mercury's surface. MESSENGER Mission urn:nasa:pds:context:investigation:mission.messenger data_to_investigation MESSENGER GRS MESSENGER Spacecraft urn:nasa:pds:context:instrument_host:spacecraft.mess is_instrument_host GRS Instrument urn:nasa:pds:context:instrument:grs.mess is_instrument Mercury Planet urn:nasa:pds:context:target:planet.mercury collection_to_target Image_Object display_settings_to_array Sample Left to Right Line Top to Bottom -180.0 180.0 90.0 -90.0 Equirectangular 0.0 0.0 Coordinate Pair 21 21 2 2 -7560 -3780 planetocentric Mercury 2440. 2440. 2440. Positive East 10.1016/j.icarus.2015.02.002 Peplowski et al., 2015, Geochemical terranes of Mercury's northern hemisphere as revealed by MESSENGER neutron measurements, Icarus, 253, 346-363. thermal_neutron_map.img 2016-03-18T17:32Z 259200 Image file in standard PDS4 IMG format Mercury Thermal Neutron Map Image_Object 0 2 Last Index Fastest The file has 259200 elements, which correspond to a 720 x 360 degree map (0.5 degree wide pixels in east longitude, latitude). The elements are arranged from the top (90 lat, -180 lon) across, then down (last entry is -90, 180). Each element is a byte. Pixel values range from 0 to 255; converting them to physical units (10^-4 cm2/g) requires multiplying the pixel value by 0.222860. Pixel values of zero are unmapped, and this corresponds to all latitudes less than (south of) 20 deg N. UnsignedByte 10**-4 cm**2/g 0.222860 0 Line 360 1 Sample 720 2 thermal_neutron_map.jp2 Image file in JPEG2000 format 0 J2C