JunoCam: Maps Archive

In this section are collections of global maps made from JunoCam’s color images at each perijove.  Juno is in a highly elliptical, near-polar orbit, so on each orbit JunoCam takes well-resolved images within just a few hours around closest approach, which is called perijove (PJ).  As Juno is moving very rapidly at that time, the camera scans a 58-degree-wide field of view in narrow red, green and blue strips, and a single image is assembled from a long sequence of these strips taken during one rotation of the spacecraft at 2 rpm.  The movement between successive strips makes it essential to reproject them to produce a single image; then, to compensate for distortions caused by movement and perspective, and to combine multiple images and put them in context, it is essential to reproject the images into maps. The intention of the JunoCam project was for this to be done by citizen scientists, so that is the origin of the maps in this archive.  

Three sets of maps are provided here in three projections: cylindrical (global), south polar, and north polar.  Each set is a provided as a ZIP file covering 8 or more perijoves, with maximum file size 48 MB.

The maps were all made by Gerald Eichstädt and John Rogers, with a few exceptions as noted individually.  For most perijoves, the maps have also been posted in the individual perijove reports by J.R. (available on this site under ‘Reports’ and ‘Predict Maps’), often with annotations.  Here, all maps are given without annotations, although annotated copies of some are included.  Scales of latitude (planetocentric) and longitude (System 3, L3) have been added to most maps. There is some variation in format, especially for the early perijoves.

The raw images were processed and map-projected by G.E., then the single-image maps were composited by J.R., except for the later perijoves when G.E. used a semi-automatic assembly technique. There are small uncertainties in navigation so positions may be uncertain by a few pixels. Intensities and color balance are arbitrary, and have been adjusted to reduce visible seams between images and to enhance regional contrast. Therefore, any broad diffuse features should not be relied on without consulting the original single-image maps.  Adjustment of color balance was especially necessary in the later years as the raw images became progressively redder due to effects of radiation on the camera.  For JunoCam’s methane-band images, G.E. also made map projections, which have been assembled and included here for some but not all perijoves.

The cylindrical (global) maps are in equirectangular projection at 10 pixels/degree and with L3=0 at the centre.  The polar maps are in polar azimuthal equidistant projections at various scales, with L3=0 to the left for the south, L3=0 to the right for the north.  In addition to the regular south polar maps, we include compilations of such maps from JunoCam and from ground-based observers which are Supplementary Figures for a published paper.  In addition to the regional north polar maps, from PJ41 onwards we include higher-resolution sets of latitudes above 70 or 75°N, showing the circumpolar cyclones. 

For further details of the separate map sets, please see the ‘ReadMe’ files posted with each group.  

Most of the maps are in JPEG format, to keep file sizes manageable, but TIF or PNG files are available from J.R. if needed. He can be contacted through the web site of the BAA Jupiter Section at https://britastro.org/sections/jupiter   via 'Contact the Director ’

The global coverage has varied during six years of the mission due to the evolution of Juno’s orbit and the constraints of spacecraft orientation. JunoCam mainly views the northern hemisphere when inbound and the southern hemisphere when outbound.  In the first year, JunoCam usually covered both hemispheres extensively.  In subsequent years, coverage was often less complete, but with resolution higher over parts of the northern hemisphere, lower over the southern hemisphere. There were no images at PJ2 and PJ71, none of the northern hemisphere at PJ19 and PJ48, and none of the southern hemisphere at PJ56. 

The maps are provided under a CC-BY license: “The CC BY license allows anyone to: copy, distribute and transmit work; adapt work; make commercial use of the work under the condition that the user must attribute the work in the manner specified by the author or licensor (but not in any way that suggests they endorse the user or their use of the work).”  I.e. these maps are in the public domain but should always be credited as indicated (NASA / JPL / SwRI / MSSS / Gerald Eichstädt / John Rogers); and we ask that anyone wishing to use them for research or commercial purposes would contact us . 
These sets of maps, and all individual perijove reports, can also be found on the BAA Jupiter Section web site at:  https://britastro.org/sections/jupiter  (under ‘JunoCam Global Maps  ’ and ‘Results from Juno: Jupiter's polar regions  ’).