io_low_simp.raw latest IO images
io_low_sinu.raw latest IO images
io_med_simp_grid.raw latest IO images
io_med_simp_nogrid.raw latest IO images
io_hires_simp.raw latest IO images
io_hires_sinu.raw latest IO images
o1.vic Voyager 2 mosaic reprojected to io.mos1 geometry
g1.vic Voyager 2 mosaic reprojected to io.mos1 geometry
b1.vic Voyager 2 mosaic reprojected to io.mos1 geometry
c1.vic Voyager 2 mosaic reprojected to io.mos1 geometry
v1.vic Voyager 2 mosaic reprojected to io.mos1 geometry
u1.vic Voyager 2 mosaic reprojected to io.mos1 geometry
3full.red, 3full.grn, 3full.blu New Galileo color images of Io.
gllvoy.red, gllvoy.grn, gllvoy.blu Resurfacing of the Jupiter-facing hemisphere of Io.
ra.red, ra.grn, ra.blu Massive resurfacing of the Ionian volcano Ra Patera.
loki.red, loki.grn, loki.blu Changes near Loki Patera on Io.
euboea.red, euboea.grn, euboea.blu Unusual volcanic pyroclastic deposits on Io.
garcia.red, garcia.grn, garcia.blu Surface changes on Io, unnamed volcanic center (latitude +11, longitude 337)
3change.red, 3change.grn, 3change.blu Three surface changes on Io
eclipse.red, eclipse,grn, eclipse.blu too_hot_for_europa Io eclipse image cleaned up and color-coded. For your eyes only. Vicar format
G1DLR_IO_MEDIA.RED, .GRN, and .BLU Io color comparison w. Voyager and names
G1DLR_IO_PELE.RED, .GRN, and .BLU Io color comparison w. Voyager and names
G1DLR_IO_LOKI.RED, .GRN, and .BLU Io color comparison w. Voyager and names
io_1.dat1 first frame of possible Io movie
io_15.dat1 15th frame of posssible Io movie
io_30.dat1 30th frame of possible Io movie
io_1.dat2 first frame of possible Io movie, different scale
io_15.dat2 15th frame of possible Io movie, different scale
io_30.dat2 30th frame of possible Io movie, different scale
IO_MOVIE.AVI Io rotation movie from DLR
IOMOVIE.CUB Io movie, isis format, from Alfred
g2dlr_io_col_1.red false color composite of Io's anti-Jovian hemisphere
g2dlr_io_col_1.grn and "natural" color
g2dlr_io_col_1.blu
io_g2_color.red false color image of Io against Jupiter's atmosphere
io_g2_color.grn used for press release
io_g2_color.blu
g2dlr_io_col_1.red improved false color composite of Io's anti-Jovian hemisphere
g2dlr_io_col_1.grn and "natural" color
g2dlr_io_col_1.blu
iotop1n.clean IO Noise cleanup only, integer (16-bit)
iotop1n.filt IO Noise cleanup and filtering, byte
iotop1s (.clean and .filt)
iotop2 (.clean and .filt)
iotop3n (.clean and .filt)
iotop3s (.clean and .filt)
iotop4 (.clean and .filt)
iotop5 (.clean and .filt)
stereo1.lft, stereo1.rgt stereo pair from East of Volund
stereo2.lft, stereo2.rgt stereo pair around Marduk
s0368981445.byt Io
s0368981500.byt Io
C3_Io_topo.vic Io C3 Topographic Mapping Mosaic
C3_Io_topo.gif with lat-lon grid
E4DLR_Culann_G2_E4.* Io color composite of Culann area
E4DLR_Io_GloCol_1.* Io -processed from E4 to E6 color data
C3_Io_topo.vic Io C3 topographic mapping mosaic
G2C3_Io.blu Io G2-C3 color topographic fusion
G2C3_Io.grn same
G2C3_Io.red same
io_global_color.vic global color composite from G1 and G2
io_eclipse_grl.tiff color coded eclipse images from G1, E4, E6
G1ISGLOMON03_grn.red .grn .blu false color of the green G1 global monitor
G1ISGLOMON03_red.red .grn .blu false color of the red G1 global monitor
G1ISIOECLI02.red .grn .blu false color of the clear G1 eclipse
E4ISIOECLI01_clr.red .grn .blu false color of the clear E4 eclipse
E4ISIOECLI01_756.red .grn .blu false color of the 7560 E4 eclipse
E6ISECLIPS01.red .grn .blu false color of the clear E6 eclipse
G7ISECLIPS01_clr.red .grn .blu false color of the clear G7 eclipse
G7ISECLIPS01_grn.red .grn .blu false color of the green G7 eclipse
G7ISECLIPS01_red.red .grn .blu false color of the red G7 eclipse
G7ISECLIPS01_vlt.red .grn .blu false color of the violet G7 eclipse
G7ISECLIPS02.red .grn .blu false color of the clear G7 eclipse #2
G8ISECLIPS01.red .grn .blu false color of the clear G8 eclipse
C9_Io_topo.vic black and white C9 image of Io
C9_Io_topocolor.red red of color image based on C9 orbit
C9_Io_topocolor.grn green of the same
C9_Io_topocolor.blu blue of the same
G7_Io_topo.vic two views of Io from orbit G7
G7_Io_topocolor.red red of color image from orbit G7
G7_Io_topocolor.grn green of the same
G7_Io_topocolor.blu blue of the same
E6_Io_full.*, *=red, grn, blu E6 full-disk color image (756, grn, vlt)
C9_Io_full.*, *=red, grn, blu C9 full-disk color image (756, grn, vlt)
Io_GRL_Fig1.*, *=red, grn, blu Three color coded images of Io in eclipse
CLR.MSK Various Io elcipse products, see explanations below
GRN.MSK
RED.MSK
VLT.MSK
CLR.ZM
GRN.ZM
VLT.ZM
RED.ZM
RED_CLR_WDG.*
RED_CLR_WDG_MSK.*
VLT_CLR_WDG.*
VLT_CLR_WDG_MSK.*
C10_Io_Pillan.vic Eruption on Io blackens an area the size of Arizona
IO_GLOBAL_LAMA_GRID.PS Io Global Mosaics
IO_GLOBAL_SIMP_GRID.PS
IO_GLOBAL_TOPO_LAMA_GRID.PS
IO_GLOBAL_TOPO_SIMP_GRID.PS
Io_Pillan_G7-C10.*, * = red, grn, blu New version of Pillan Arizona-size eruption G7 to C10 comparison
C9_Io_Pillan_topo.*, * = red, grn, blu Color Mosaic and Active Volcanic Plumes on Io
C9_IO_PILLAN_TOPO.TIF Tif version of above merged in Photoshop
C10_Io_a-axis-gas.*, * = red, grn, blu Io degassing from sub- and anti-Jupiter regions.
889_slide.readme Io 889 absorptions...
889_slide.tif
889_slide.vic
E11DLR_2nd_family_portrait.tiff 4 Galilean satellites+Amalthea+Thebe+Metis+Adrastea
(in Callisto.products directory)
G2_Io_TD_enhTD.tiff G2 Io global, enhanced
IO_E14.TIFF preliminary 889-GRN-VIO composite from the Io E14 data
E14_Io_I24context.tif E14 Io image black/white showing context for I24
frames (with features labeled) from McEwen
E14.vic Geissler's Io color submission to Science for cover
(high resolution disk w/ e/w sides out of frame)
io_science.tif Final version of E14.vic for Science magazine cover
##########################################################################
Search on the following email messages by file name for more information.
##########################################################################
##########################################################################
>From trosanov@flagmail.wr.usgs.gov Tue Jul 2 09:35:49 1996
To: all_hiips@noao.edu, sue_lavoi@iplmail.jpl.nasa.gov,
helen_mortensen@iplmail.jpl.nasa.gov, agd@kookaburra.jpl.nasa.gov,
spencer@lowell.edu
Subject: Re: latest IO images
Cc: trosanov@flagmail.wr.usgs.gov
X-Sun-Charset: US-ASCII
PLEASE DISREGUARD ALL PREVIOUS MESSAGES CONCERNING IO MOSAICS AS THERE WAS
AN ERROR IN THE RESOLUTION OF THE IO_LOW_SIMP AND SINU MOSAICS. THEY ARE
ACCURATE (HOPEFULLY) AT THIS TIME.
The voyager control base mosaic for IO is complete.
The images processed are Voyager I and II clear and blue filters.
This is the lastest mosaic of IO without the smoothing filter.
The products are available on our ftp site:
ftp -i ftpflag.wr.usgs.gov
username: ftp
password: (your e-mail address)
ftp>cd pub/outgoing
ftp>binary
ftp>get (filename)
The files in the pub/outgoing directory are compressed files. If you notice
each one has the ending '.cub.gz.' However, if you use the "get" command in
ftp and only designate the filename without the '.gz' and end only with the
".cub" our ftp device will uncompress the files prior to transfer for you.
The files can be transfered as compressed files and using the "gunzip" command on unix to uncompress the files at your convience.
EXAMPLE::: on unix ----- gunzip io_med_simp.cub.gz
this will uncompres the file and maintain the name/
EXAMPLE::: ftp>get io_med_simp.cub
If there are any problems please e-mail trosanov@flagmail.wr.usgs.gov
THE LOW RESOLUTION FILES ARE NOT COMPRESSED
Description/filenames of products available (two formats) -
1) Global mosaic - lowres
Filenames: io_low_simp.cub (isis format)
io_low_simp.raw (raw file - no labels)
Description:
Projection: Simple Cylindrical
kilometers/pixel scale: 3.94
latitude range: -90.0, 90.0
longitude range: 0.0, 360.0
center latitude: 0.0
center longitude: 180
bit type: 8 (byte)
number of lines: 1440
number of samples: 2880
size: 4 megabytes (uncompressed)
2) Global mosaic - lowres
Filenames: io_low_sinu.cub (isis format)
io_low_sinu.raw (raw file - no labels)
Description:
Projection: Sinusoidal
kilometers/pixel scale: 3.94
latitude range: -90.0, 90.0
longitude range: 0.0, 360.0
center latitude: 0.0
center longitude: 180.0
bit type: 8 (byte)
number of lines: 1440
number of samples: 2880
size: 4 megabytes (uncompressed)
3.) Global mosaic - merge of lowres,wideangle,mediumres and hires with a grid.
Filenames: io_med_simp_grid.cub (isis format)
io_med_simp_grid.raw (raw file - no labels)
Description:
Projection: Simple Cylindrical
kilometers/pixel scale: 0.9912380
latitude range: -90.0, 90.0
longitude range: 0.0, 360.0
center latitude: 0.0
center longitude: 180.0
bit type: 8 (byte)
number of lines: 5760
number of samples: 11520
grid latitude inc: 10 degrees
grid longitude inc: 10 degrees
size: 66 megabytes (uncompressed)
4.) Global mosaic - merge of lowres,wideangle,mediumres and hires.
Filenames: io_med_simp_nogrid.cub (isis format)
io_med_simp_nogrid.raw (raw file - no labels)
Description:
Projection: Simple Cylindrical
kilometers/pixel scale: 0.9912380
latitude range: -90.0, 90.0
longitude range: 0.0, 360.0
center latitude: 0.0
center longitude: 180.0
bit type: 8 (byte)
number of lines: 5760
number of samples: 11520
size: 66 megabytes (uncompressed)
5.) Partial global mosaic - merge of lowres,wideangle,mediumres and hires,
covering the area of the highest resolution on Io.
Filenames: io_hires_simp.cub (isis format)
io_hires_simp.raw (raw file - no labels)
Description:
Projection: Simple Cylindrical
kilometers/pixel scale: 0.4956
latitude range: -90.0, 90.0
longitude range: -131, 61
center latitude: 0.0
center longitude: -35.0
bit type: 8 (byte)
number of lines: 11520
number of samples: 12288
size: 141 megabytes (uncompressed)
6.) Partial global mosaic - merge of lowres,wideangle,mediumres and hires,
covering the area of the highest resolution on Io.
Filenames: io_hires_sinu.cub (isis format)
io_hires_sinu.raw (raw file - no labels)
Description:
Projection: Sinusoidal
kilometers/pixel scale: .4956
latitude range: -90.0, 90.0
longitude range: -131, 61
center latitude: 0.0
center longitude: -35.0
bit type: 8 (byte)
number of lines: 11520
number of samples: 12288
size: 141 megabytes (uncompressed)
#######################################################################
#######################################################################
>From all_hiips-request@noao.edu Thu Jul 11 16:51:37 1996
>From mcewen
Subject: Io analysis
Dear Iologists,
Voyager 2 mosaic reprojected to io.mos1 geometry
is available from ftpflag.wr.usgs.gov /pub/outgoing,
iovoy2o.cub
iovoy2g.cub
iovoy2b.cub
iovoy2c.cub
iovoy2v.cub
iovoy2u.cub
(or, gr, bl, clear, vio, uv filters)
Also available in vicar format: o1.vic, g1.vic, b1.vic, c1.vic, v1.vic, u1.vic
Somebody needs to make slides comparing these (v and g)
to SSI vlt and grn filters, rotated ~180 deg., for Torrence to show at COSPAR.
Description of Io file:
The filters appear to be arranged as follows:
756 vio
red grn
The exposures are excellent except a bit dark for vio.
Compression artifacts are minor on Io's disk, but beware of features near
the limb that might be misinterpreted. A single bright noise hit will cause
low-level high-frequency structure throughout the 8x8 block.
We do expect to get the remainder of the frame (bottom of red and grn disks).
############################################################################
From: Alfred McEwen (GD.Flagstaff) (520)556-7194
Received: by masursky.wr.usgs.gov (8.7.5) id RAA15029; Fri, 26 Jul 1996 17:09:41 -0700 (MST)
Date: Fri, 26 Jul 1996 17:09:41 -0700 (MST)
Message-Id: <199607270009.RAA15029@masursky.wr.usgs.gov>
To: all_hiips@noao.edu
Subject: Processed Io images
X-Sun-Charset: US-ASCII
Status: RO
Galileo Io images for potential category A releases:
I have ftped seven color image sets to Rushmore
in vicar format. Below are extended captions and
discussions of each.
The images on Rushmore are either in the directory
/home/ssi/review (which is full) or in /home/axm.
KEN, HELEN ET AL. AT JPL and ELIZ: PLEASE DO NOT DELETE
THESE FILES WITHOUT FIRST MAKING COPIES OR RUNNING THRU
PHOTOGRAPHIC PROCESSING.
I recommend everyone take a look at the first color
set below, which is stunning.
3full.red, 3full.grn, 3full.blu
New Galileo color images of Io. Three full-disk color
views are shown, in natural color (top) and enhanced
color (bottom, near-IR, green, and violet images). The
natural color images reveal that some areas on Io are
truly red, whereas much of the surface is yellow or
light greenish. Accurate natural color renditions were
not possible from Voyager images because there was no
coverage in the red. The major red areas shown here
appear to be closely associated with very recent
fragmental volcanic deposits (pyroclastics) erupted in
the form of volcanic plumes. The most prominent red
oval surrounds Pele (right-hand image), as previously
discovered from HST images. An intense red spot lies
near the active plume Marduk east of Pele. Other
reddish areas are associated with known hot spots or
regions that have changed substantially since the
Voyager flybys. The red material appears to be
unstable, so the color fades over time. This fading
appears to occur most rapidly in the equatorial region
and more slowly over the polar regions, so surface
temperature controls the rate of transformation. Note
that the polar regions seen in the right-hand view are
not reddish, perhaps because reddish pyroclastics have
not been recently deposited here. The absence of
uniform polar coverage by reddish materials indicates
that the red materials probably do not result from
atmospheric condensation or bombardment by energetic
particles. These characteristics and the spectra of
the red materials are consistent with the unstable
short-chain sulfur allotropes (S3 and S4). S3/S4 may
form from the rapid freezing of fine sulfur droplets or
from dissociation of SO2 in high-temperature eruptions
to form S2O (which is bright white) followed by further
partial dissociation into S3/S4 and SO2. The reddish
deposits may therefore be the products of high-
temperature explosive volcanism.
Many changes are apparent compared to Voyager
images, as shown in accompanying images. The new
deposits appear to correspond to one or more of four
spectral end-members: reddish materials discussed
above, dark materials in flows and on caldera floors,
bright white materials (SO2 frost), and bright yellow
materials such as the new flows surrounding Ra Patera.
There are some curious differences in the overlap
region between the left-hand and middle images. There
are several especially bright areas in the left-hand
image, which appear much darker in the middle image.
These may represent transient eruptions or surface
materials with unusual scattering properties. Several
differences can also be seen near the persistent hot
spot Kanehekili (latitude -15, longitude 38).
Several volcanic plumes active during the Voyager
flybys in 1979 occurred near the bright limbs or
terminator regions of these images, where airborne
materials should be detectable. Loki and Amirani
appear to be inactive, Volund is active, and Pele may
be active but is extremely faint. The plume Marduk
also seems to be active, and dark jets of erupting
materials can be seen against the disk.
Several previously unknown mountains can be seen
near the terminators. They appear to occur
preferentially within bright white (SO2-rich) regions.
All images in orthographic projection. For scale,
the Io's diameter is 3632 km. Central longitudes are
69 degrees (left), 338 degrees (middle), and 264
degrees (right). Together these three views cover
about 75% of Io's surface.
gllvoy.red, gllvoy.grn, gllvoy.blu
Resurfacing of the Jupiter-facing hemisphere of Io.
Shown here are views of Io from Voyager 1 high-
resolution images (upper left), Voyager 1 color (upper
right), Voyager 2 color (lower left), and Galileo color
(lower right). Color is constructed from the Voyager
orange and violet bandpasses or from the Galileo green
and violet bandpasses, adjusted to provide comparable
color balances. Many changes between Voyager 1,
Voyager 2, and Galileo orbit G1 images are evident,
some of which are illustrated and discussed in detail
in accompanying illustrations. The most dramatic
changes between Voyagers 1 and 2, just 4 months apart,
were the effects of the eruptions of Surt and Aten
Patera. Each eruption darkened the caldera floor and
left diffuse pyroclastic deposits covering areas ~1400
km in diameter (about the size of Alaska). The caldera
of Surt occurs at latitude +45 degrees, and the caldera
of Aten occurs at latitude -48 degrees. The Galileo
image is surprising because the Surt and Aten regions
appear much more similar to the Voyager 1 pre-eruption
images than to the Voyager 2 images. Closer inspection
reveals traces of the Surt and Aten plume deposits,
especially where surrounding features appear muted and
in the presence of faded bright red materials in the
Galileo red and infrared colors, but the plume deposits
have largely "faded away" and the calderas have
brightened. The Surt and Aten plume deposits had
spectral properties (determined from Voyager colors)
similar to the plume deposits of Pele. Pele's deposits
have not faded away, suggesting that Pele had remained
intermittently active whereas Surt and Aten are only
rarely active.
ra.red, ra.grn, ra.blu
Massive resurfacing of the Ionian volcano Ra Patera.
Shown here are four views of Ra Patera (latitude -8,
longitude 325): Voyager 1 high resolution (upper left),
Voyager 1 color (upper right), Voyager 2 color (lower
left), and Galileo color (lower right). Although there
may have been some subtle changes between Voyagers 1
and 2, a very major change occurred sometime between
March 1994 and July 1995, as revealed by HST (Spencer
et al., paper submitted to Icarus). A spot centered
more-or-less on Ra Patera brightened dramatically and
revealed color properties consistent with a mixture of
elemental sulfur and SO2. The Galileo images reveal
the morphology of the new deposits in much greater
detail. Dark materials, previously confined to a
summit caldera, appear to have overflowed the caldera
walls to produce a small flow to the south and a larger
flow to the southeast. New bright deposits covering an
area of about 40,000 square kilometers (the size of New
Jersey) surround the dark materials. The bright
materials have sharp lobate margins in places, and
appears to have embayed a plateau (upper left),
suggesting emplacement as lava flows rather than
pyroclastics. Note that the Voyager 1 images also
revealed relatively bright lava flows emanating from Ra
Patera, especially to the northeast. No intense
thermal emissions have been detected in the vicinity of
Ra Patera. Although hot-spot monitoring has been
sporadic and a significant brightening could have
occurred, it is extremely unlikely that such extensive
flows could consist of high-temperature silicate lava
and pass largely undetected in the hot-spot monitoring.
Most likely the changes over Ra Patera resulted from
the emplacement of a low-temperature fluid such as
sulfur. The colors of the flows match those of sulfur
plus SO2 frost. The bright, fresh sulfur would create
a cold trap for atmospheric SO2. The Ra Patera region
in anomalously bright on the nightside of Io in the red
bandpass, perhaps due to fluorescence of SO2
dissociation products. Images are 953 km wide.
loki.red, loki.grn, loki.blu
Changes near Loki Patera on Io. Shown here are four
views of Loki Patera: Voyager 1 high resolution (upper
left), Voyager 1 color (upper right), Voyager 2 color
(lower left), and Galileo color (lower right). During
the Voyager flybys large dense volcanic plumes were
erupting from each end of the "fissure" or dark linear
feature to the northeast of the dark caldera, and the
plumes and plume deposits obscured or mantled much of
the surrounding surface. The Loki plumes may be
inactive or have reduced activity at the time of the
Galileo G1 encounter (lower right). Dark jets
emanating from the fissure ends are not visible in the
Galileo image. Earth-based monitoring showed that Loki
was unusually quiescent during the G1 encounter, so the
reduced plume activity suggests that plume activity is
correlated with thermal emission. There have been
several subtle surface changes. The fissure appears
extended and elongated to the east and to the
southwest, perhaps also resulting in a migration of the
plume vents. There is an enlarged dark spot to the
west of Loki. The color of materials just south and
northeast of the caldera have changed to a more reddish
color. Earth-based monitoring showed that Loki was
unusually quiescent during the G1 encounter, so the
reduced plume activity suggests that plume activity is
correlated with thermal emission.
Loki has been by far the most energetic and active
hot spot on Io over the past two decades, so the
subtlety of the surface changes is surprising.
However, the thermal signature of Loki is consistent
with silicate volcanism with new flows covering areas
of a few tens of square kilometers per year. This rate
of silicate resurfacing is tremendous by terrestrial
standards, but the new flows could easily be "hidden"
within the large dark caldera floor of Loki. Hence,
the style of effusive volcanism at Loki is in stark
contrast to that at Ra Patera. Ra Patera has
resurfaced an enormous area but with accompanying
thermal radiation several orders of magnitude below
that of Loki, whereas Loki may have resurfaced a
relatively small area by lava flows, but accompanied by
enormous thermal radiation.
Images 894 km wide.
euboea.red, euboea.grn, euboea.blu
Unusual volcanic pyroclastic deposits on Io. Shown
here are four views of Euboea Fluctus (latitude -45,
longitude 351): Voyager 1 high resolution (upper left),
Galileo enhanced color (upper right; near-IR, green,
and violet colors), Voyager 2 color (lower left), and
Galileo color (lower right). New diffuse deposits are
seen in the Galileo images, but with an unusual
morphology for plume deposits. A diffuse yellowish
deposit with a radius of 285 km extends to the
northwest, whereas an intense reddish deposit marks a
curving fallout margin to the southeast. This
morphology may have resulted from the presence of a
topographic obstruction to southeast of the vent. A
hot spot was detected near Euboea Fluctus on June 2,
1996. Images are 772 km wide.
garcia.red, garcia.grn, garcia.blu
Surface changes on Io. This unnamed volcanic center
(latitude +11, longitude 337) has experienced may
changes in appearance since Voyager images were
acquired, including new dark and bright deposits. This
region was a hot spot during Voyager 1. Images are 762
km wide.
3change.red, 3change.grn, 3change.blu
Three surface changes on Io are illustrated here,
comparing subscenes of Voyager 2 images (left) with
subscenes of Galileo images (right). At top (latitude
+33, longitude 20) is a new volcanic feature consisting
of a dark spot (perhaps a caldera floor) surrounded by
a diffuse circular ring of reddish material, perhaps a
plume deposit. In the middle are new dark linear
features within a field of lava flows (latitude +13,
longitude 359), which corresponds to a hotspot observed
by Dumas, Spencer and Stansberry on June 2, 1996. At
bottom is shown the region near Sengen Patera (lower
dark feature in Voyager image; latitude -32, longitude
305); the dark materials have brightened or have been
buried by new bright deposits by the time of Galileo.
The Sengen Patera region was also observed to include a
hot spot June 2, 1996. Images are all 500 km wide.
Dozens of other obvious large-scale (100 km or larger)
changes are apparent on new Galileo images of Io.
#################################################################
>From ssi_science-request@noao.edu Thu Aug 1 13:25:17 1996
To: ssi_science@noao.edu
Subject: Io and Europa products
X-Sun-Charset: US-ASCII
On Rushmore /home/ssi/review are the following:
eclipse.red, eclipse,grn, eclipse.blu
too_hot_for_europa Io eclipse image cleaned up and
color-coded. For your eyes only. Vicar format
eurfilt.vic (vicar) and eurfilt.cub (ISIS)
Europa 4-image controlled mosaic with filters
to enhance detail. Processing by Cynthia Phillips
and myself.
Alfred
// //==\
// // //
// \==//
===============================================================================
From: Tilmann Denk, Peter Schuster, Gerhard Neukum (DLR Berlin)
Subj: Io color frames: Surface feature naming and Voyager/Galileo G1 comparison
===============================================================================
Files content:
In each file, the left image is a Galileo G1 NIR-GRN-VLT image (colors
enhanced),
the mid-frame shows the same image, but labelled with names of surface
features,
and the right frame shows a Voyager ORG-BLU-VIO image of similar viewing angle.
File Galileo Voyager
G1DLR_IO_MEDIA.* G1 VGR-2
Center longitude 69 W 67 W
Resolution 23 km/pxl 18 km/pxl
G1DLR_IO_PELE.* G1 VGR-2
Center longitude 264 W 216 W
Resolution 14 km/pxl 13 km/pxl
G1DLR_IO_LOKI.* G1 VGR-2
Center longitude 338 W 330 W
Resolution 15 km/pxl 13 km/pxl
I have placed 6 images of Io /home/ssi/review on rushmore. These images have
been run through unmosaic, catlabel, galsos, ictfix, and sized up by at least
a factor of 2. They have been stretched and converted to byte.
io_1.dat1, io_15.dat1, and io_30.dat1 are the first, 15th and 30th frames and
have been sized up by 2.
io_1.dat2, io_15.dat2, and io_30.dat2 are the first, 15th and 30th frames and
are scaled to the same size as io_30.dat2 (io_30.dat1 and io_30.dat2 are the
same).
Let me know what you think of these images. Thanks.
--jan yoshimizu
Dear friends of Io:
Rushmore directory
/home/ssi/review/ contains three vicar files,
g2dlr_io_col_1.red
g2dlr_io_col_1.grn and
g2dlr_io_col_1.blu
which show a false color composite of the newest Io images of the
anti-Jovian hemisphere. The three filters NIR, GRN, and VLT have been used
for the red, green, and blue channel, respectively. Each channel has been
histogram-stretched and high-pass filtered separately.
Note the bluish areas in both polar hemispheres and the "silver bluish"
features at mid-latitudes (especially in the western part of Colchis Regio).
In a "true" color frame, they appear rather greyish. Could these be different
materials in addition the ones we have thought of so far (cf. tomorrow's
Science article)?
Best regards,
Tilmann Denk, Peter Schuster, Gerhard Neukum
Dear Iophiles:
The new data which have been made available by JPL a few hours ago have been
added to the G2DLR_Io_Col_1.* vicar files on Rushmore. Additionally, a rather
"natural" color version of this Io image has also been included. The files
g2dlr_io_col_1.blu
g2dlr_io_col_1.grn
g2dlr_io_col_1.red
on Rushmore's home/ssi/review directory therefore now contain two
versions of the Io anti-Jovian side G2 image: a "natural" color image on top
and a false color image at the bottom (the "Christmas tree ball" version).
Viele Gruesse from Berlin,
Tilmann
Helen,
/home/ssi/review/io_g2_color.cub is ready for photolab
vicar format: io_g2_color.red, .grn, .blu
caption material:
False-color image of Io seen against Jupiter's atmosphere,
acquired during the second Ganymede orbit (G2) orbit.
This is the best and highest resolution image acquired of
Io thus far by Galileo, centered on the side of Io that always
faces away from Jupiter. Color is composed of the near-infrared,
green, and violet images, enhanced to emphasize color and
brightness variations on Io. The active plume Prometheus is
near the right-center area of the disk. There have been many
surface changes since the Voyager flybys 17 years ago, and even
a few changes since Galileo's G1 orbit 2 months earlier. The
black and bright red materials correspond to the most
recent volcanic deposits, probably no more than a few years old.
4.93 km/pixel resolution, which exceeds the best Voyager coverage over the
right (eastern) half of this hemisphere.
##########################################################################
>From ssi_science-request@noao.edu Fri Sep 27 07:14:30 1996
To: ssi_science@noao.edu
Cc: "TERRA::NEUKUM"@psi.pe.ba.dlr.de, "TERRA::ROATSCH"@psi.pe.ba.dlr.de
Subject: G2 Io rotation movie
*******************************************************************************6
Dear team members and associates,
We used the images of Io taken during G2 to produce a movie. It shows Io
rotating under the approaching spacecraft. We did some image processing
to improve the contrast, to sharpen and to brighten the images.
The movie runs for about 3 seconds. It looks good when run in endless mode,
if one doesn't mind the jump every three seconds.
We transferred two copies on the Rushmore, one of them is in quicktime format,
the other in avi format.
LOCATION (MOVIE): /home/tyr/movie
File names are IO_MOVIE.AVI and IO_MOVIE.QTM
With best regards -Peter Schuster, Roland Wagner
##########################################################################
>From ssi_science-request@noao.edu Sun Oct 6 12:14:17 1996
To: ssi_science@noao.edu
Subject: Io G2 rotation movie and plume analysis
Cc: jry@potato.jpl.nasa.gov, helen_mortensen@quickmail382.jpl.nasa.gov,
rlopes@jpluvs.jpl.nasa.gov, spencer@lowell.edu
SSI/Iophiles,
In /home/ssi/review on Rushmore is a 36-step movie of Io rotation.
iomovie.cub -- ISIS format. Either run isis2vicar to convert to
Vicar, run readisis and movie in idl, or use cv (idl/isis).
ICTFIX greatly improved the appearance of these images.
I repeated frames to fill 10-deg limb coverage
gaps; the movie could be improved by reprojecting
images to fill the gaps. Also, the movie would be
improved by rotating all frames to exact same north angle.
I think Helen and Jan at MIPS will make these improvements
for the final movie to be released at DPS.
Analysis:
Active Plumes:
Prometheus is quite obvious, both near bright limb, terminator
and from stereo views as it crosses the sunlit disk. It appears
to be about 75 km high, and especially uv-bright.
Culann Patera (lat -19, long 160--just SW of Prometheus) appears to
another, smaller active plume. The central bright spot shows clear
paralax displacements as the viewing angle changes, similar to
Prometheus, and we can see a bright plume-like feature here in the G1
eclipse image. It is now clear that the eastern limb of the eclipse
image is especially bright primarily due to a concentration of active
plumes--Volund, Prometheus, and Culann.
Pele -- truth window was returned over limb region with Pele very near
bright limb; no plume can be seen. However, given the short exposures,
the SNR may be no better than the G1 grn image with Q=3 ICT compression,
so we haven't really made any progress here in determining if Pele
has an active but very faint plume.
Further plumes might be detected from reprojections for stereo viewing.
Several other plumes seen or suspected to be active in G1 (Ra, Marduk, Volund)
are not apparent near bright limb against black sky. It's unlikely that
all are inactive in G2; we probably can't see them due to the combination
of faintness and lossy compression.
G1-G2 surface changes:
The only G1-G2 difference that seems likely to be due to a real surface
change (or airborne material) is a brightening of the SW portion of
Loki caldera.
Photometry:
The 3 bright patches near lat 0 long 20, which appeared especially bright
in one G1 image set (48 deg phase) but not another (25 deg phase), appears
especially bright again at relatively high phase (~60 deg) but not at
lower phase (15 deg). Viewing and illumination angle changes (alone) do
not appear to be important. Therefore, these patches must be
especially forward-scattering. This is also the approx. location of a
high-temperature event observed by Spencer et al. just days before the G2
encounter, but the images do not seem to reveal evidence for surface changes.
Ra Patera appears different than in G1 as brightest regions are no longer
unusually bright. However, phase angle is ~60 deg rather than 25 (G1).
Ra Patera is still brighter in HST images (~5 deg phase). These bright
materials must be especially backscattering.
Gibil Patera is nearly indistinguishable in the G2 images (60 deg phase;
included in Pele truth window). It was dark in G1, 25 deg phase and one
othe brightest features seen at 122 deg G1, so the 60 deg observation is
intermediate. This is an unusually forward-scattering dark material.
Sequence Planning post-mortem:
I think this was a near-miss for the plume inventory objective. If the
exposures had been longer (to increase plume-space contrast) and compression
less (such as 20:1 after windowing as originally planned, rather than 30:1
used to due expected D/L shortage), I think we would have succeeded in detecting
most plumes larger than ~50 km and at least as bright as Voyager-detected
plumes. Nevertheless, we have detected Prometheus and Culann, obtained
useful phase-function information, and produced an interesting Io rotation
movie, all for 0.5 Mbits (~0.1 frame equivalent). I think we should try
this type of observation set again, with longer exposures and less compression,
during the Europa phase of GEM---it fits nicely as it requires significant tape
but little D/L, the opposite of Europa high-res observations.
Alfred
##########################################################################
From: MX%"DENK@terra.pe.ba.dlr.de" 25-OCT-1996 08:37:04.52
To: MX%"ssi_science@noao.edu"
CC: MX%"DENK@terra.pe.ba.dlr.de"
Subj: G2 Io color image on Rushmore
Dear friends of Io:
The vicar files
G2DLR_Io_Col_1.red, grn, blu on Rushmore's
/home/ssi/review
directory have now been completed. Major differences to the previously
released image (P-47971) are:
Left image: - Less enhanced, more "natural" colors.
Right image: - Much more enhanced than P-47971;
- Co-registration of atmospheric features 350,000 kilometers
behind Io included
Viele Gruesse from Berlin,
Tilmann
##########################################################################
>From ssi_science-request@noao.edu Fri Oct 25 08:37:30 1996
To: ssi_science@noao.edu
Cc: DENK@terra.pe.ba.dlr.de
Subject: G2 Io color image on Rushmore
Dear friends of Io:
The vicar files
G2DLR_Io_Col_1.red, grn, blu on Rushmore's
/home/ssi/review
directory have now been completed. Major differences to the previously
released image (P-47971) are:
Left image: - Less enhanced, more "natural" colors.
Right image: - Much more enhanced than P-47971;
- Co-registration of atmospheric features 350,000 kilometers
behind Io included
Viele Gruesse from Berlin,
Tilmann
###########################################################################
Date: Wed, 4 Dec 1996 16:02:27 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
Message-Id: <199612042302.QAA13044@io.PIRL>
To: all_hiips@noao.edu
Subject: Io C3 images: clean/filtered versions
X-Sun-Charset: US-ASCII
Content-Length: 333
X-Lines: 15
Status: RO
On Rushmore /home/axm are the following files
in Vicar format:
iotop*.filt Noise cleanup and filtering, byte
iotop*.clean Noise cleanup only, integer (16-bit)
* = 1n, 1s, 2, 3n, 3s, 4, 5
*.clean are especially for DLR stereo modelers.
*.filt are spectacular images to any geologist
Stereo pairs will follow.
Alfred
From: MX%"mcewen@pirl.lpl.arizona.edu" 12-DEC-1996 11:13:50.74
To: MX%"all_hiips@noao.edu"
Subj: Re: Io C3 images: clean/filtered versions
New versions of iotop5.filt and iotop5.clean are now
available on Rushmore, with gaps filled. Remaining gaps in
iotop1n, 1s, 2, 3n, and 4 are not expected to be filled.
>
> On Rushmore /home/axm are the following files
> in Vicar format:
>
> iotop*.filt Noise cleanup and filtering, byte
> iotop*.clean Noise cleanup only, integer (16-bit)
>
> * = 1n, 1s, 2, 3n, 3s, 4, 5
>
> *.clean are especially for DLR stereo modelers.
>
> *.filt are spectacular images to any geologist
>
> Stereo pairs will follow.
>
> Alfred
>
From: MX%"mcewen@pirl.lpl.arizona.edu" 12-DEC-1996 12:01:40.95
To: MX%"ssi_science@noao.edu"
Subj: Io releases for Press conference at the AGU
Mike,
Here are the 2 Io images, with captions, that I suggest
we release at AGU.
Alfred
#1. on Rushmore /home/axm/iotop3s.filt
> Geologic Landforms on Io
>
> Shown here is one of the highest-resolution image of Io acquired by the Galileo
> spacecraft, revealing a great variety of landforms. There are rugged
> mountains several miles high, layered materials forming plateaus, and
> many irregular depressions called volcanic calderas. Similar landforms
> were seen near Io's south pole by the Voyager spacecraft, but Galileo has
> revealed that such landforms are ubiquitous. Several of the dark, flow-like
> features correspond to hot spots, and may be active lava flows. There
> are no landforms resembling impact craters, as the volcanism covers the
> surface with new deposits much more rapidly than the flux of comets and
> asteroids can create large impact craters.
>
>
> Frame number 368599813, acquired at range of 245,719 km on Nov. 6, 1996,
> with a spatial resolution of 2.5 km/pixel. The image covers an area
> 2000 km wide.
#2. on Rushmore /home/axm/iotop3n.filt samples 3-495 and lines 185-679
Volcanically Active Regions on Io
Shown here is a portion of one of the highest-resolution images of Io acquired
by the Galileo spacecraft, revealing immense lava flows and other
volcanic landforms. Several high-temperature volcanic hot spots
have been detected in this region by both the Near Infrared Mapping
Spectrometer and the imaging system of Galileo. The temperatures
are consistent with active silicate volcanism in lava flows or
lava lakes (which reside inside irregular depressions called calderas).
The large
dark lava flow in the upper left region of the image is more than 400
km long, similar to ancient flood basalts on Earth and mare lavas on
the Moon.
Frame number 368599800, acquired at range of 245,719 km on Nov. 6, 1996,
with a spatial resolution of 2.5 km/pixel. The image covers an area
21230 km wide.
###########################################################################
From: MX%"oberst@beta.pe.ba.dlr.de" 5-DEC-1996 10:32:12.77
To: MX%"ssi_science@noao.edu"
CC:
Subj: Io stereo views
Dear Colleagues,
we have computed two stereo views from the recent C3 Io
image sequence and have copied them to rushmore /home/pjo.
File names are: stereo1.lft, stereo1.rgt, stereo2.lft,
stereo2.rgt
In detail: the first pair combines images #58239 and
#78900 from sequences topo1 and topo2 showing an area east of
Volund. These are converted to a sinusoidal map
projection with identical map scale 3.5 km, center lat=20 deg,
and center long=150 deg West.
The second pair combines topo 3 and topo4 #99813 and #20000
images showing an area centered around Marduk. Theses are
reprojected to map scale 3.0 km, center lat=-20 deg, and
center long=210 deg West.
Stereo effects in the images are quite small (compared to
Ganymede) due to the low resolution of the images. But we do
see topographic highs and lows. Digital stereo analysis is
currently under way - we hope to have preliminary results by the
end of the week.
Cheers,
DLR stereo team
>From amy_culver@quickmail384.jpl.nasa.gov Tue Dec 17 16:58:16 1996
Subject: C3 products ready for your
To: "Mike Belton"
Hi Mike,
The following files are available on Rushmore in /home/adc:
Io:
The Io files are called s0368981445.byt and s0368981500.byt. s0368981500.byt
was the top image and s0368981445.byt was the bottom image (more saturated).
The bottom image has been registered to the top, so you can use jblink to
compare them, or just display them in the red and green planes of your
display. (The display seems to look best with s0368981445.byt in the red plane
and s0368981500.byt in the green plane.)
There are a couple of bright stars which line up nicely in both images.
Amy
From: MX%"mcewen@pirl.lpl.arizona.edu" 3-MAR-1997 13:05:31.57
To: MX%"all_hiips@noao.edu"
Subj: Io C3 mosaic
Io C3 Topographic Mapping Mosaic
VICAR format: on Rushmore.jpl.nasa.gov /home/ssi/review/C3_Io_topo.vic
(warning: files may be deleted from Rushmore after 2 weeks due to
restricted disk space.)
ISIS format: on pirl.lpl.arizona.edu /galileo3/mosaics/C3_Io_topo.cub,
(contact joep@pirl.lpl.arizona.edu if you need an account on pirl)
On both Rushmore and pirl:
C3_Io_topo.gif (GIF format, with 10 degree lat-lon grid)
C3_Io_topo.README (this file)
Description: Mosaic of SSI C3 clear-filter images of Io.
Projection: Simple Cylindrical
kilometers/pixel scale: 2.0
latitude range: -72, 90
longitude range: 92, 326
center latitude of projection: 0.0
bit type: 8 (byte)
number of lines: 2569
number of samples: 3704
size: 9.5 megabytes (uncompressed)
Frame numbers: s0368558239, s0368558252, s0368578900, s0368599800,
s0368599813, s0368620000, s0368641300
Eliz: Feel free to use this (GIF version with grid) as a class B release.
In fact I would prefer
early release so non-SSI members of the Io Working Group can access this mosaic
for the effort to update Io's nomenclature.
Alfred
-------------------------------------------------------------------------------
>From ssi_science-request@noao.edu Fri Mar 7 08:12:43 1997
Date: Fri, 7 Mar 1997 16:10:49 +0100 (CET)
From: Tilmann Denk
To: ssi_science@noao.edu
Cc: DENK@kappa.pe.ba.dlr.de
Subject: Io E4 SSI 6-color observation
Content-Length: 5666
***************************************************************************
From: Tilmann Denk, Gerhard Neukum
To: Iophiles of SSI_Science list
Subj: Io E4 SSI 6-color observation
Date: 07-Mar-1997
***************************************************************************
Dear Iophiles:
There are new Io color composites on Rushmore's /home/ssi/review directory:
(1) E4DLR_Culann_G2_E4.*
(2) E4DLR_Io_GloCol_1.*
The "*" stands for red, grn, or blu; all files have Vicar format.
Enjoy them!
Here is a description of the images, combined with some preliminary
statements:
(1) E4DLR_Culann_G2_E4.* is a comparison of the Culann area on Io between
Sep-1996 and Dec-1996. I seems that the red deposit started to fade. For
example, the "connection" between the red and the dark material on the left
side of Culann Patera disappeared. Additionally, the red deposit left to a
smaller dark spot in the left part of the image is virtually absent in the
E4 frame. The images also suggest that the distance between the dark and
the red parts of Culann increased between September and December.
(2) E4DLR_Io_GloCol_1.* is processed from the E4 Io 6-color data (in the
real world, 4_1/3 colors are available) and shows Io in three different
ways: (a) Enhanced-color image, (b) near-infrared colors, and (c) a false
color ratio image. The "enhanced-color image" is composed by the NIR, GRN,
and VLT filters. On the left side, there is a small, wedge-shaped gap in
the overlap between the two green-HMA frames, which has cosmetically been
removed. The "infrared image" is composed by the 1MC, NIR, and GRN filters.
E4 has been the first time that Galileo returned Io images in the 1MC
filter. The "ratio image" is a composite of three color ratios: Red channel
is 1MC/NIR, green channel is GRN/VLT, and blue channel is VLT/NIR.
. In the ratio image, reddish and orange hues indicate a reddish slope in
the spectrum between 0.76 and 1 um. This is seen in some polar regions and
for the various dark spots on the surface. The latter are clearly visible
as "red dots" in the ratio image. When looking at the red channel only,
this is still more obvious. (The bright dots that survived the CR removal
filter correspond to the dark spots on Io.)
. The greenish colors appear in the ratio image when the spectral slope is
very steep between 0.41 and 0.56 um. At longer wavelengths, the greenish
hues suggest a flat spectrum. These are properties of sulfur spectra. In
the enhanced-color image, these areas appear yellow.
. Bluish or violet hues can be seen in the ratio image for "flatter"
(although not totally flat) spectra between 0.41 and 0.76 um. In the
enhanced-color image, these areas appear white or slightly blue. They might
be correlated with a higher amount of SO2, which has it's spectral red edge
at shorter wavelengths and should not be detectable by SSI.
- The reddish polar areas are clearly different to the red deposits like
the one near Culann. While the Culann deposits are not striking in the
1MC/NIR color ratio, the polar areas show an increasing slope towards 1 um.
- The dark spots have steeper spectra in the near-IR than all other areas
on Io. Additionally, the MT2-filter 1/3-image (0.89 um, not shown here)
shows slight "absorptions" for the dark spots, compared to a continuum
defined by the NIR and the 1MC filter. No such 0.89-"absorptions" are seen
for the bright plains. This might be suggestive of a higher amount of
silicates there. Another explanation might be that hot spot emission
radiation slightly increases the DNs of the dark spots in the 1 um image
(although this is hard to imagine, considering the short exposure times).
- New plume deposit (since G2) at the north pole: The ratio image indicates
that this is more similar to the green equatorial areas in the ratio image.
When correlating this green color to sulfur, the "new volcano" seems to be
sulfur driven rather than silicatic, not surprising when looking at the
areal extent of the deposit. The center of the deposits appears bluish (but
is located at the very edge of the frame, so statements are difficult).
- The bright equatorial band virtually disappears in the 1MC/NIR ratio (as
already stated by Damon in his e-mail from 18-Feb-1997), indicating that
all materials responsible for the yellow/white/reddish appearance in
"natural" color images have a similar spectral behavior (here: flat) at
near-IR wavelengths. This might be consistent with SO2 and sulfur as
surface materials.
- Near the poles, some areas show increasing slopes in their spectra,
indicated by orange hues in the ratio image. This suggests the presence of
additional material(s) in this area.
- At the limb, the visual impression in all three images given here is that
no "color shift" is present, like for example in the G2 Europa image, where
bluish hues increase towards the limb / terminator / increasing
incident/emission angles. (Both images have very low phase angles.)
The strength of the 6-color images are especially observations of the dark
spots and the reddish polar terrain. This finding might be used for
planning of subsequent observations and possible high-resolution
observations at the end of the GEM.
So far a first description of the E4-Io-6-color image and some preliminary
statements of what might be seen there. We want to say thank-you again to
all people who made these "long"-wavelength observations possible,
especially Damon, Alfred, and Dave. Damon: The drink you requested in your
e-mail from 14-Dec-1996 is not forgotten.
Viele Gruesse from Berlin,
Gerhard Neukum and Tilmann Denk
#######################################################################
>From all_hiips-request@noao.edu Sun Mar 9 15:23:22 1997
Date: Sun, 9 Mar 1997 15:22:00 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
To: all_hiips@noao.edu, eliz@noao.edu
Subject: Io G2-C3 color-topo merge
X-Sun-Charset: US-ASCII
Content-Length: 1940
Liz: please proceed with the B release on the B&W mosaic (C3_Io_topo.tiff).
We could also release the color merge as either A or B.
Alfred
Io C3 Topographic Mapping Mosaic
VICAR format: on Rushmore.jpl.nasa.gov /home/ssi/review/C3_Io_topo.vic
(warning: files may be deleted from Rushmore after 2 weeks due to
restricted disk space.)
ISIS format: on pirl.lpl.arizona.edu /galileo3/mosaics/C3_Io_topo.cub,
(contact joep@pirl.lpl.arizona.edu if you need an account on pirl)
On both Rushmore and pirl:
C3_Io_topo.tiff (TIFF format, with 10 degree lat-lon grid)
C3_Io_topo.README (this file)
Description: Mosaic of SSI C3 clear-filter images of Io.
Projection: Simple Cylindrical
kilometers/pixel scale: 2.0
latitude range: -72, 90
longitude range: 92, 326
center latitude of projection: 0.0
bit type: 8 (byte)
number of lines: 2569
number of samples: 3704
size: 9.5 megabytes (uncompressed)
Frame numbers: s0368558239, s0368558252, s0368578900, s0368599800,
s0368599813, s0368620000, s0368641300
G2-C3 Color-Topographic Fusion
VICAR format: on Rushmore.jpl.nasa.gov /home/ssi/review/G2C3_Io.*,
* = red, grn, blu
(warning: files may be deleted from Rushmore after 2 weeks due to
restricted disk space.)
ISIS format: on pirl.lpl.arizona.edu /galileo3/mosaics/G2C3_Io.cub,
(contact joep@pirl.lpl.arizona.edu if you need an account on pirl)
Description: Merge of G2 color with C3 topographic mapping.
Projection: Orthographic
kilometers/pixel scale: 2.0
latitude range: -90, 90
longitude range: 84.56, 264.56
center latitude of projection: 0.63
center longitude of projection: 174.56
bit type: 8 (byte)
number of lines: 1817
number of samples: 1817
size: 9.9 megabytes (uncompressed)
Frame numbers: G2: s0359986578, s0359986604, s0359986607
C3: s0368558239, s0368558252, s0368578900, s0368599800,
s0368599813, s0368620000, s0368641300
From: MX%"geissler@amalthea.lpl.arizona.edu" 24-MAR-1997 16:44:31.61
To: MX%"ssi_science@noao.edu"
Subj: Io global color
Hello,
A global color mosaic of Io produced from G1 and G2 data has been placed
in ssi_review for consideration as a Category B release.
io_global_color.vic is a VICAR composite with R, G, B = band 1, 2, 3
io_global_color.jpg is a losslessly compressed version, also available at
http://pirl.lpl.arizona.edu/hiips/Io_Color/
The original 16-bit, 4-band cube is available on pirl as
/galileo3/mosaics/io_global_color_16.cub
Appended is a draft Category B caption.
Cheers, Paul Geissler
geissler@pirl.lpl.arizona.edu
__________________________________________________________________________
(For the web pages: Link the release clause below to the
release policy paragraph previously provided.)
*******************************************************
This JPEG image is made available in order to share with the public the
excitement of new discoveries being made via the NASA/JPL Galileo spacecraft.
Galileo scientists are in the process of calibrating and validating this data.
The full digital image necessary for scientific analysis will be released
within one year of receipt of this orbit's last data.
*******************************************************
TITLE: Global Mosaic of Io.
This false-color infrared composite of Jupiter's moon Io was produced from
images acquired during Galileo's first two orbits, at resolutions ranging
from 10 to 23 km/pixel and phase angles from 4 to 55 degrees. SSI 756 nm,
Green and Violet filter data are shown as red, green, and blue, respectively.
The area shown is 11,420 km in width. Grid lines are superimposed at latitude
and longitude intervals of 30 degrees. Deposits of sulfur dioxide frost appear
in white and grey hues, while bright red materials (such as the prominent ring
surrounding the currently erupting plume Pele) mark areas of recent volcanic
activity and are usually associated with high temperature, low albedo edifices
which show significant change between the Voyager and Galileo eras.
The Jet Propulsion Laboratory, Pasadena, CA manages the
mission for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted
on the World Wide Web, on the Galileo mission home page at URL
http://www.jpl.nasa.gov/galileo. Background information
and educational context for the images can be found at URL
http://www.jpl.nasa.gov/galileo/sepo
--------------------------------------------------------------------------------
>From ssi_team-request@noao.edu Mon Mar 31 12:36:38 1997
To: ssi_team@noao.edu
Subject: Io eclipse figure
On Rushmore, /home/ssi/review/io_eclipse_grl.tiff
is an illustration showing E4, E6, and G1 color-coded
eclipse images and, below each, the G1G2 color mosaic
produced by Paul Geissler reprojected to the geometry
of each eclipse image. This will be Figure 1 of
McEwen et al., High-Temperature Hot Spots on Io Imaged
by the Galileo Solid State Imaging (SSI) Experiment.
Hot-spot co-authors and those interested in the diffuse
plume/atmospheric glows should look at this figure.
It can be released when the GRL paper is published.
Image also avail. on pirl /galileo3/review
--------------------------------------------------------------------------------
>From jry@potato.JPL.NASA.GOV Tue Jul 8 13:31:30 1997
To: eliz@noao.edu
Subject: Eclipse images
I've put the images on rushmore in /home/jry/ema. I have a file called
readme.txt which has info about the images. All the images except 2 are north
down. There is one Europa eclipse with the others. There are also
G1ISGLOMON03 images with the eclipse images. Let me know if you have any
questions.
--jan
7/8/97
All are north down except G1ISIOECLI02 and E6ISECLIPS01 have north up.
IO
G1ISGLOMON03 S0349673952.LBL (grn) CONV=1.0 (0,1350) -> (0,255)
G1ISGLOMON03 S0349673965.LBL (red) CONV=1.0 (0,1350) -> (0,255)
G1ISIOECLI02 S0350029700.LBL (clr) CONV=0.00001 (400,2600) -> (0,255)
E4ISIOECLI01 S0374478046.UM0 (clr) CONV=0.0001 (250,390) -> (0,255)
E4ISIOECLI01 S0374478268.UM0 (7560) CONV=0.001 (400,490) -> (0,255)
E6ISECLIPS01 S0383809200.M6 (clr) CONV=0.00001 (200,1750) -> (0,255)
G7ISECLIPS01 S0389608268.UM0 (clr) CONV=0.00001 (1450,3250) -> (0,255)
G7ISECLIPS01 S0389608300.UM0 (grn) CONV=0.0001 (600,740) -> (0,255)
G7ISECLIPS01 S0389608322.UM0 (red) CONV=0.0001 (500,620) -> (0,255)
G7ISECLIPS01 S0389608345.UM0 (vlt) CONV=0.0001 (2500,3150) -> (0,255)
G7ISECLIPS02 S0389608845.UM0 (clr) CONV=0.0001 (190,380) -> (0,255)
G8ISECLIPS01 S0394394200.UM0 (clr) CONV=0.0001 (35,200) -> (0,255)
CONV=r
where r specifies the output DN scale in number of nanowatts per cm**2 per
steradian per nanometer wavelength per DN.
S2 K
r = e * -------- * ---
A2(t-to) Ko
where
A2 = number of nanowatts per cm**2 per steradian per nanometer
wavelength per DN.
e = z(d - dc)
where z is retrieved from the Radiometric File and dc is retrieved
from the Dark-Current File.
S2 is the filter-dependent conversion factor from ft-Lamberts
to units of nanowatts/cm**2/steradian/nanometer.
t = commanded exposure time of the input image (msec).
to = line-dependent shutter offset.
K = system gain constant for the gain-state of the image.
Ko = system gain constant for the calibration file gain-state.
--------------------------------------------------------------------------------
>From ssi_science-request@noao.edu Thu Sep 11 13:23:40 1997
Date: Thu, 11 Sep 1997 13:12:07 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
To: ssi_science@noao.edu
Subject: Io C9 release
X-Sun-Charset: US-ASCII
Content-Length: 1024
Status: RO
X-Lines: 34
Eliz:
Two processed images are available for release:
on Rushmore in vicar format:
/home/ssi/review
C9_Io_topo.vic
C9_Io_topocolor.*, * = red, grn, blu
also available as ISIS cubes on pirl /galileo3/review/Io
Caption materials:
1. (black&white)
This image of Io was acquired by Galileo on _____, orbit C9,
as part of a sequence of images designed to cover Io at low
illumination angles to map the landforms. Several mountains up to
a few miles high can be seen in this view, especially near the upper
right. Some of these mountains appear to be tilted crustal blocks.
frame # 401785378, picno C9I0010, 8.3 km/pixel
2. (color)
This picture was produced from images of Io was acquired by
Galileo on _____, orbit C9, as part of a sequences of images designed
to map landforms and monitor changes in the surface color due to
volcanic activity. Most of the dark spots correspond to active
volcanic centers.
frame # 401785378, 400, 403, 407, picno C9I0010-13, 8.3 km/pixel
red, green, violet filters
--------------------------------------------------------------------
>From ssi_science-request@noao.edu Mon Sep 15 10:44:25 1997
Date: Mon, 15 Sep 1997 10:41:30 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
To: eliz@noao.edu
Subject: Io release
Cc: ssi_science@noao.edu
X-Sun-Charset: US-ASCII
Content-Length: 633
Status: RO
X-Lines: 19
G7 Io topography images
Rushmore /home/ssi/review/G7_Io_topo.vic
PIRL: /galileo3/review/Io/G7_Io_topo.cub
Frames G7I0030, 40, s0389752400 s0389771978
clear filter, 5.7 and 6.2 km/pixel
Caption material.
Two views of Io from orbit G7. These images were acquired to
image large landforms on Io at low sunangles. Sunangles are low near
the terminator (day-night boundary near left side of images). These
images reveal that the topography is very flat near the active volcanic
centers such as Loki Patera (large dark horseshoe-shaped feature in
left-hand image), and that a variety of mountains and plateaus exist
elsewhere.
------------------------------------------------------------------
>From ssi_science-request@noao.edu Mon Sep 15 18:08:09 1997
Date: Mon, 15 Sep 1997 18:06:28 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
To: eliz@noao.edu
Subject: Io release
Cc: ssi_science@noao.edu
X-Sun-Charset: US-ASCII
Content-Length: 366
Status: RO
X-Lines: 15
Eliz,
Another Io release:
Rushmore: G7_Io_topocolor.*, * = red, grn, blu
PIRL: G7_Io_topocolor.cub
frames G7I0040,50-52, color merged with full-res clear
(389752400, 389771978, 2000, 2004)
6.1 km/pixel (12.2 km/pixel color, vlt, grn, red)
Color image of Io acquired in orbit G7. The big red ring
marks the fallout deposit of the Pele eruption.
Alfred
---------------------------------------------------------------
Date: Thu, 2 Oct 1997 17:17:44 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
Message-Id: <199710030017.RAA08957@io.PIRL>
To: eliz@noao.edu
Subject: 3 more Io releases
Cc: ssi_science@noao.edu
X-Sun-Charset: US-ASCII
Status: R
1. Full-disk color of Loki-Pele hemisphere
Rushmore: /home/ssi/review/E6_Io_full.*, * = red, grn, blu, VICAR
Pirl: /galileo3/review/Io/E6_Io_full.cub, ISIS
E6 full-disk color image (756, grn, vlt) showing Pele (big red ring)
and Loki (dark horseshoe). The new deposits at Ra Patera (below Loki)
have faded in appearance since G1 images were acquired (compare to
image XXX). Amaterasu Patera (dark spot north of Loki) has darkened
since G1.
Frame #s 383758500, 507, 511
2. Full-disk color of Kanehekili hemisphere
Rushmore: /home/ssi/review/C9_Io_full.*, * = red, grn, blu, VICAR
Pirl: /galileo3/review/Io/C9_Io_full.cub, ISIS
C9 full-disk color image (756, grn, vlt) showing the hemisphere of Io
centered at longitude 52 degrees. The dark feature just to the lower
right of the center of the disk is Kanehekili, location of a persistent
hot spot and an active volcanic plume.
Frame #s 401740700, 707, 711
3. Eclipse images of Io (Note: release on October 15 when GRL Io section
is published)
Rushmore: /home/ssi/review/Io_GRL_Fig1.*, *=red, grn, blu VICAR
PIRL: /galileo3/review/Io/Io_GRL_Fig1.cub ISIS
Three color coded images of Io in eclipse (top), showing volcanic hot
spots and airglow associated with volcanic plumes and Io's atmosphere.
At bottom are the corresponding views of Io in reflected light,
reprojected from a global mosaic (see release XXX). This image is
Figure 1 of "High-Temperature Hot Spots on Io as seen by Galileo's Solid
State Imaging (SSI) Experiment", published in Geophysical Research
Letters, October, 1997.
Frame #s (from left to right): 374478045, 383809200, 350029700
---------------------------------------------------------------
>From ip@linax1.mpae.gwdg.de Thu Jul 31 01:13:12 1997
To: MBELTON@noao.edu
Subject: Product from Amy Culver
Date: 22 Jul 1997 15:20:11 -0800
From: "Amy Culver"
Subject: Io Eclipse images
To: "Wing Ip"
CC: "Helen Mortensen" , "Jan
Yoshimizu"
Hi Wing,
I have put the files you requested on a computer where you should be able to
access them via anonymous FTP. The machine is rushmore.jpl.nasa.gov, and the
files are located in /pub/io. I have also generated prints which I will put
into the mail for you. The products are:
1) Radiometrically corrected, hot pixel streaks removed, general noise
subtracted (via the method we used with Mike), despiked, converted to byte
values and sized up by a factor of 5. All files are 850 lines by 745 samples:
Filename: Radiance (CONV=0.0001) to byte conversion:
clr.zm 0 (radiance) -> 0 (byte), 801 (radiance) -> 255 (byte)
red.zm 0 -> 0, 108 -> 255
vlt.zm 0 -> 0, 419 -> 255
grn.zm 0 -> 0, 115 -> 255
2) Same products as in step 1), but these images have a mask which indicates
line/sample locations around edges. All files are 1269 lines by 948 samples.
clr.msk
red.msk
vlt.msk
grn.msk
3) Use the clr.zm and red.zm (still in units of radiance, prior to conversion
to byte) to generate ratio: (CLR/RED)*10000. Convert from halfword units (of
radiance/radiance) to byte values: 0 -> 0 , 32767 -> 255. Display in
pseudocolor with wedge. Files are red_clr_wdg.red, red_clr_wdg.grn,
red_clr_wdg.blu. Did the same using violet instead of red, files are
vlt_clr_wdg.red, vlt_clr_wdg.grn, vlt_clr_wdg.blu. All files are 680 lines by
710 samples.
4) Same products as in step 3), but these images have a mask. All files are
811 lines by 810 samples.
red_clr_msk_wdg.red
red_clr_msk_wdg.grn
red_clr_msk_wdg.blu
vlt_clr_msk_wdg.red
vlt_clr_msk_wdg.grn
vlt_clr_msk_wdg.blu
I hope these are the products you were interested in seeing. If you have
further questions or processing needs, please let me know. If there is any
confusion or the results aren't what you were expecting, maybe the next step
would be to talk to Ken Klaasen about this problem. He seems to understand
the workings of our calibration software plus the on-chip mosaicking process
and may be able to help.
Amy
---------------------------------------------------------------
Date: Wed, 8 Oct 1997 16:13:39 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
Message-Id: <199710082313.QAA14154@io.PIRL>
To: Gerhard.Neukum@dlr.de, carr@astmnl.wr.usgs.gov, denk@terra.pe.ba.dlr.de,
ealvarez@noao.edu, kenneth.p.klaasen@Jpl.Nasa.Gov,
mcewen@pirl.lpl.arizona.edu, tjohnson@jpltvj.jpl.nasa.gov,
belton@jupiter.tuc.noao.edu
Subject: C10 Io release
Cc: ssi_science@noao.edu
X-Sun-Charset: US-ASCII
Status: RO
Rushmore /home/ssi/review/C10_Io_Pillan.vic
Pirl /galileo3/review/Io/C10_Io_Pillan.cub
Eruption on Io blackens an area the size of Arizona
Shown here is comparison of Io images acquired in
orbit G7 (left) and C10 (right). A new dark
spot 400 km in diameter surrounds a volcanic
center named Pillan patera. Galileo imaged a 120
km high plume erupting from this location in orbit
C9. Pele, the larger plume deposit southwest of Pillan,
also appears different than it did in G7, perhaps
due to interaction between the two large plumes.
(Some of the apparent differences here are due to
different spectral bandpasses and different phase
angles.) The color of Pillan's plume deposits
(dark at all wavelengths) differs from that of Pele
(very red), but is similar to the deposits of
Babbar Patera (dark feature southwest of Pele).
G7: 389752400, clear filter, 5.7 km/pixel
C10: 413744178, green filter, 5.1 km/pixel
Color will be even better...but not yet on the ground.
---------------------------------------------------------------
Date: Thu, 9 Oct 1997 16:39:09 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
Message-Id: <199710092339.QAA15866@io.PIRL>
To: all_hiips@noao.edu
Subject: Io global mosaics
X-Sun-Charset: US-ASCII
Status: RO
Io Global Mosaics
Four versions of Io global mosaics (all Galileo) are available
on Rushmore /home/ssi/review (*.vic, VICAR format) and
Pirl /galileo3/mosaics/Io (*.cub, ISIS format)
Best resolution versions:
Io_global_simp_grid Simple Cylindrical projection
Io_global_lama_grid Lambertian equal-area projections
Versions including near-terminator imaging for topography:
Io_global_topo_simp_grid Simple Cylindrical projection
Io_global_topo_lama_grid Lambertian equal-area projections
For all of the above:
Scale km/pix: 2.0
Latitude range: -90,90
Longitude range: 0, 360
Clon: 180 (simp); 270 and 90 (lama)
Clat: 0
Bit type: 8
Number of lines: 2570
Number of samples: 5140
Size: 13.2 megabytes
SSI IMAGE NUMBERS:
G1: 349746300 (green filter)
G2: 359986578 (green filter)
(all others clear filter)
C3: s0368558239, s0368558252, s0368578900, s0368599800,
s0368599813, s0368620000, s0368641300
E6: 383694100
G7: 389752400, 389771978
C9: 401785378
C10: 413627200
---------------------------------------------------------------
Date: Tue, 28 Oct 1997 15:19:13 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
Message-Id: <199710282219.PAA00752@io.PIRL>
To: Jane.Platt@Jpl.Nasa.Gov
Subject: Io press release
Cc: ssi_science@noao.edu, helen_mortensen@quickmail384.jpl.nasa.gov
X-Sun-Charset: US-ASCII
Status: R
New version of Pillan Arizona-size eruption G7 to C10
comparison, in color. Caption material will follow.
Rushmore: /home/ssi/review/Io_Pillan_G7-C10.*, * = red, grn, blu VICAR
Pirl: /galileo3/review/Io/Io_Pillan_G7-C10.cub ISIS
Helen: this needs to go to photolab
---------------------------------------------------------------
Date: Thu, 23 Oct 1997 16:07:59 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
Message-Id: <199710232307.QAA22870@io.PIRL>
To: eliz@noao.edu
Subject: Io release
Cc: ssi_science@noao.edu
X-Sun-Charset: US-ASCII
Status: R
Eliz,
Image for release (and framed for Doug Nash retirement):
On Rushmore /home/ssi/review
C9_Io_Pillan_topo.*, * = red, grn, blu
On Pirl /galileo3/review/Io
C9_Io_Pillan_topo.cub
(For the web pages: Link the release clause below
to the release policy paragraph previously provided.)
*******************************************************
This JPEG image is made available in order to share with
the public the excitement of new discoveries being made via
the NASA/JPL Galileo spacecraft. Galileo scientists are
in the process of calibrating and validating this data.
The full digital image necessary for scientific analysis will be
released within one year of receipt of this orbit's last data.
*******************************************************
TITLE: Color Mosaic and Active Volcanic Plumes on Io
This color image, acquired during Galileo's ninth orbit around Jupiter,
shows two volcanic plumes on Io. One plume was captured on the bright limb
or edge of the moon (See inset at upper right.), erupting over a caldera
(volcanic depression) named Pillan Patera. The plume seen by Galileo
is 140 kilometers (86 miles) high, and was also detected
by the Hubble Space Telescope. The Galileo spacecraft will pass
almost directly over Pillan Patera in 1999 at a range of only 600 (373 miles).
The second plume, seen near the terminator (boundary between day and night),
is called Prometheus after the Greek fire god. (See inset at lower right.)
The shadow of the airborne plume can be seen extending to the right
of the eruption vent. (The vent is near the center of the bright and dark
rings). Plumes on Io have a blue color, so the plume shadow is reddish.
The Prometheus plume can be seen in every Galileo image with the appropriate
geometry, as well as every such Voyager image acquired in 1979.
It is possible that this plume has been continuously active for more than
18 years. In contrast, a plume has never been seen at Pillan Patera
prior to the recent Galileo and HST images.
Color images from orbit C9 have been merged with a high-resolution mosaic
of images acquired in various orbits to enhance the surface detail.
North is to the top of the picture. The resolution is about 2 kilometers
(1.2 miles) per picture element. This composite uses images taken
with the green, violet, and near-infrared filters of the solid state imaging
(CCD) system on NASA's Galileo spacecraft. The C9 images were obtained
on June 28, 1997 at a range of more than 600,000 kilometers (372,000 miles).
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission
for NASA's Office of Space Science, Washington, DC. JPL is an operating
division of California Institute of Technology (Caltech).
This image and other images and data received from Galileo are posted
on the World Wide Web, on the Galileo mission home page at URL
http://www.jpl.nasa.gov/galileo. Background information and
educational context for the images can be found at URL
http://www.jpl.nasa.gov/galileo/sepo
---------------------------------------------------------------
>From ssi_science-request@noao.edu Wed Nov 26 12:50:21 1997
Date: Wed, 26 Nov 1997 12:42:45 -0700
From: mcewen@pirl.lpl.arizona.edu (Alfred McEwen)
To: eliz@noao.edu
Subject: AGU release
Cc: ssi_science@noao.edu, jane.platt@Jpl.Nasa.Gov
X-Sun-Charset: US-ASCII
Content-Length: 1126
X-Lines: 27
Status: RO
rushmore /home/ssi/review/C10_Io_a-axis-gas.*, * = red, grn, blu
pirl /galileo3/review/Io/C10_Io_a-axis-gas.cub
Io degassing from sub- and anti-Jupiter regions.
Shown here are color-coded eclipse images acquired
in orbit C10 (top) and the corresponding views in
reflected light (bottom). The white lines delimit
Io's equator and longitudes 0 (left) and 180 (right).
Io always keeps the same hemisphere (longitude 0)
facing Jupiter, just as the near side of the Moon
always faces Earth. Furthermore, Io is not a perfect
sphere--it is elongated along the "a" axis radial to
Jupiter. The solid-body tides on Io have the greatest
amplitude (~50 m) where the a axis intersects the surface,
at the sub-Jupiter point (lat. 0, long. 0) and at the
anti-Jupiter point (lat. 0, long 180). From these
eclipse images we see evidence for enhanced concentrations
of volcanic gases (dominantly SO2) at the sub- and anti-
Jupiter regions. This enhanced degassing may be due
directly to the tides or may be due to enhanced heat
flow at depth below these regions.
left: C10I0001 (13.2 km/pixel)
right: C10I0100 (63 km/pixel)
--------------------------------------------------------------------------
>From ssi_science-request@noao.edu Fri Jan 30 11:44:52 1998
>From Alfred
To: ssi_science@noao.edu
Subject: Re: Io 889 absorptions....
Mike, Paul, Ken, Damon, Clark,
Thanks for all the feedback. Some responses and additional comments follow.
First, I've put a band depth map into Rushmore /home/ssi/review
and PIRL /galileo3/review/Io:
889_slide.*, * = .cub (ISIS), .vic (VICAR) .tif (TIFF)
It shows a portion of the 756-nm image on the left and the
ratio of (756 + 1MC)/889 on the right. Dark spots include
Hi'iaka, Shamash, Kanehekili, and several dark areas in the
vicinity of Masubi. The apparent band depth reaches a
maximum of 30%, although when noise is considered
perhaps we can only be sure of 20%. However, this must be
the minimum band depth because (1) we don't know if the 889-nm
band really falls on the minimum, and (2) we don't know if
the 756 or 1MC bands are completely outside of an absorption.
I'm convinced that this is an impressive absorption band.
Only the ~5% of Io covered by dark materials shows this absorption.
The surrounding regions all have a band depth of 0 (+/- a few
percent, average over 3x3-pixel areas). To eliminate the 889-band
via global calibration coefficients would create an 889-nm peak over
95% of Io's surface, which is clearly inconsistent with telescopic
spectra. To explain the band as a calibration error requires
something that preferentially affects dark regions, i.e., an
additive error due to poor bias or scattered light corrections.
The bias corrections seem fine given that space goes to zero
(away from detectable scattered light halo). The scattered light
is greater at 889 and 1MC than at 756 according to the attenuation
models in the SSI Calibration Report, Part 2. Applying the
correction deepened the bands a little, as expected. Nevertheless,
I certainly welcome "independent" (to the degree possible) analysis
from Paul and Damon at Cornell.
Bob Carlson says they have a new calibration for the NIMS data from
0.7-1 micron, and we plan to pursue coanalysis. We have exceeded
NIMS capability only because we have the spatial resolution...but
NIMS will have better than 1 km/pixel resolution in I24/I25.
Meanwhile, NIMS can resolve the very largest dark areas such as the
Pillan fallout deposit (which may or may not have the same composition
as the dark flows). Also, the NIMS resolution in C21 will be about
like that of SSI in C10 (10 km/pixel), so we should certainly be able
to verify the band, and determine its actual shape(s) and wavelength minimum(s).
The most important result at present is the realization that there is
compositional information of the dark materials in the 1-micron region,
which is very encouraging for future observations. I'm certainly not going
to worry about what any hypothetical critics might think at this point in time.
Kari has shown that addition of 889 and 1MC images to the Io sequence in
E15, in IM8 mode (needed to minimize radiation noise without RBI and to
maximize spatial resolution) works out nicely with the current plan,
with little increase in tape, and that plenty of extra tape is available on
that track. Extra BTG would, of course, still be needed to play back the
extra data. We could consider cutout windows, but that greatly complicates
attempts to remove scattered light. We could also drop visible-wavelength
filters, but we want those for change detection, photometry, and to model
the full spectrum including sulfurous "contamination". We'll have to see
how much D/L is available, use the pass-1 preview, and make the usual
difficult tradeoffs.
Clark gave a pessimistic assessment about the ambiguity of mineral
identifications, and referred to R. Clark's mineral library. Paul has convolvey
few minerals that produce an 889-nm band relative to 756 and 1MC. An
absorption closer to 1 micron like Gaspra and Ida would have many more candidat
With NIMS coanalysis I'm hopeful that we can define the precise shape of
the band for more definitive identification.
Unbridled speculation, because its what makes planetary science fun:
It is certainly interesting that the best candidate thus far (orthopyroxene)
is a common mineral in ultramafic assemblages, consistent with the high
temperatures. Lunar mare "basalts" (which are actually more ultramafic than
terrestrial basalts) are also rich in orthopyroxene. Is Io's current-day
volcanism similar to ancient mare volcanism? The similarities in size and
bulk density of Io and the Moon make this idea plausible with respect to degrees
of partial melting needed to sparate and raise the magma, but Io
must be much more differentiated and of course has a large Fe-FeS core lacking
(or very small) in the Moon. On the other hand, the Moon probably originated
from Earth's mantle. If Io's eruptive products are somehow efficiently
mixed back into the mantle as Carr envisions, then maybe Io's mantle composition
at some level is similar to that of the Moon at some level. I do think that
Io's magma's are fairly volatile-poor, given the evidence that the plumes are
driven by near-surface interaction between silicate magma or lava and the
SO2-rich regolith or upper crustal ground fluid, and that much lava erupts
without producing detected plumes. I have joked that I like the Moon because
to me Io is normal so the Moon is bizarre and exotic. Maybe Io and the Moon have
much more in commmon than I could have imagined.
--------------------------------------------------------------------------
>From ssi_science-request@noao.edu Wed Apr 1 17:55:58 1998
Return-Path:
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Date: Thu, 2 Apr 1998 2:54:54 +0200 (CET-DST)
From: Tilmann Denk
Reply-To: Tilmann.Denk@dlr.de
To: ssi_science@noao.edu
CC: Tilmann.Denk@dlr.de
Message-Id: <980402025454.39a00075@terra.pe.ba.dlr.de>
Subject: Galilean satellites 'family portrait'
Content-Length: 538
X-Lines: 11
Status: RO
Aloha,
people who like 'family portraits' of the Jovian satellites might have a look
on file "E11DLR_2nd_family_portrait.tiff" in Rushmore's /home/ssi/review
directory. It contains very low phase observations (0-4 degrees) of the four
Galilean satellites, with an Io image from G2, Europa from C9, Ganymede from
C10, and Callisto from E11. Parts of the processing of the Europa and Callisto
images were done by Paul Geissler and Moses Milazzo, respectively. For scale
comparison, Amalthea and Thebe are also included.
-- Tilmann
>From ssi_science-request@noao.edu Thu Apr 9 15:44:26 1998
Reply-To: Tilmann.Denk@dlr.de
To: ssi_science@noao.edu
Subject: Galilean satellites 'family portrait', note
The 'family portrait' file "E11DLR_2nd_family_portrait.tiff" in
Rushmore's /home/ssi/review directory has been replaced by an improved
version. The filename did not have changed. If you already downloaded
the old file, please delete it and replace it by the new one.
-- Tilmann
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>From Tilmann.Denk@dlr.de Wed Apr 1 15:58:48 1998
To: eliz@noao.edu
Subject: 2nd famili portrait on Rushmore
the new 'Familienfoto' is now on Rushmore's /home/ssi/review, its name is
E11DLR_2nd_family_portrait.tiff
Just for fun, I also added Amalthea and Thebe images; you might keep them in
the release if you want (my preference).
For the caption, the following information (but better formulated) should
still be added:
- There is a scale bar in the image, its length is 1000 km
- Callisto SSI color data were not complete; the right edge and the polar
areas have been more or less simulated with Voyager and Galileo data. This is
probably the reason why thye dark patches that are common at equatorial
latitudes do not appear in the south-polar hemisphere.
-(if Amalthebe remain) Amalthea is number 5, Thebe no. 7 in size of Jupiter's
16 known satellites. They are shown to scale here, too. Note the huge size
difference between them and the Galilean satellites (which are no. 1-4 in size
of the JupSats).
I also put the single images of the Galilean Satellites in "maximum
resolution" on Rushmore's /home/ssi/review. Their names:
G2_Io_TD_enhTD.tiff
C9_Europa_PG_enhTD.tiff
E11_Callisto_MM_enhTD.tiff
(Ganymede is at "max-res" in the family portrait.)
For Europa and Callisto, I included the original version provided by Paul
Geissler ('PG') or Moses Milazzo ('MM') on the left, and my "enhanced"
('enhTD') version to the right. For Io, only my enhanced version is included.
You might even select both Europa images for press-release, the left one as
the "true color" version, and the right-one as the "enhanced color" version.
The same might be done for Callisto, but I guess you will use Alfred's images.
In the unlikely event that you indeed want to use the E11_Callisto_MM_enhTD
image, please tell me.
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>From ssi_science-request@noao.edu Mon Apr 13 03:32:23 1998
To: H Herbert Breneman
Cc: ssi_science@noao.edu
Subject: Re: E14 Io
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Herb and other Iophiles:
A preliminary 889-GRN-VIO composite from the Io E14 data is available
at url: http://pirlwww.lpl.arizona.edu/hiips/io_e14
Many small red deposits are seen in the 3 km/pixel data which were not
readily apparent in earlier images at lower resolution. The bright red
deposit west of Culann appears to have enlarged at its north end relative
to its appearance in G2 and E4. Although not apparent in this picture, 889
nm absorptions are seen at Culann, Prometheus and the dark spot near 23 N,
146 W, but not at others.
Cheers, Paul
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>From ssi_science-request@noao.edu Fri May 1 13:00:12 1998
>From Alfred McEwen
To: ssi_science@noao.edu, eliz@noao.edu
Subject: Re: Europa E14 products
Io product for release:
On Rushmore /home/ssi/review and Pirl /galileo3/review/Io:
E14_Io_I24context.tif
Frame 44088700.1, 2.6 km/pixel (256948 km range), clear filter
Caption:
An image of Io was acquired in orbit E14 that has the same lighting
geometry as will be present during Io's close flyby of Io in orbit
I24 on October 11, 1999. The spacecraft groundtrack on Io is shown,
with "X"s marking 2-minute time intervals. The large "X" marks the
location of closest approach, when Galileo will be just 500 km above
Io's surface. The curved boundary (left) marks the 'terminator" or
day-night boundary. The Pele volcano will be on the nightside
during the flyby, but the hot lavas can be seen glowing in the dark.
Other targets of interest that will be visible near closest approach
are Pillan Patera (the site of dramatic surface changes, see <>),
Reiden Patera, Marduk, The bright plains of Colchis regio, and the
rugged Dorian Montes (mountains). Active volcanic plumes and
high-temperature hot spots have been seen at Pele, Pillan, and Marduk.
======================================================================
>From ssi_science-request@noao.edu Fri May 15 04:03:04 1998
To: ssi_science@noao.edu
Subject: E14 Io Pass2
Dear Iophiles:
An updated 968-GRN-VIO composite from the Io E14 Pass 2 data is
available at url: http://pirlwww.lpl.arizona.edu/hiips/io_e14
As Alfred mentioned, this picture is being considered for Science.
Cheers, Paul, geissler@pirl.lpl.arizona.edu
>From mcewen@pirl.lpl.arizona.edu Thu May 21 13:27:23 1998
To: lrowan@aaas.org
Subject: Draft Science cover
Cc: geissler@pirl.lpl.arizona.edu, mcewen@pirl.lpl.arizona.edu, eliz@noao.edu
Hi Linda,
The final version and caption is now at
http://pirlwww.lpl.arizona.edu/hiips/science/ io_science.tif (named by Eliz.)
I'll print it out on the dye-sub to send to Linda.
Cheers, Paul
Caption:
At 3 km/pixel, this is the highest resolution color picture of Io yet
taken by Galileo. The satellite is seen against a backdrop of Jupiter's
cloud tops, which appear blue in this false-color composite constructed
from 1-micron, green and violet filter images. Among the surprises that
can be seen on the surface of Io are several small, distinctly greenish
patches, and subtle violet hues at the cores and margins of bright
SO2-rich regions like the one in the lower right. Dark spots, many flagged
by bright red pyroclastic deposits, mark the sites of current volcanic
activity. Most of Io's riotous color can be explained by sulfur compounds,
but the dark materials that make up the flows and calderas are probably
silicates. (Image processed by Paul Geissler, University of Arizona)
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