Pillan plume, Io, seen with HST: 0.26 - 0.41 microns, July 1997.
HST Press Release of
this image, and other images of Io transiting JupiterRaw Galileo images and NIMS spectral cubes through orbit E26 are now available here. Note: Select option "GO-J/JSA-SSI-2-REDR-V1.0" for SSI images of the Galilean satellites.
Galileo Photopolarimeter Radiometer (PPR) data are available here. This is an archive maintained by John Spencer at Lowell Observatory.
All the raw Voyager images of the Jovian satellites (and all other Voyager images) are available in GIF and other formats at the PDS Rings Node. The "advanced" catalog allows searching by resolution, which is useful if you don't know the range of FDS counts that you need. It's geared to ring images, but just reply "no" to "Ring Data Only?" and treat "Radial Resolution" as plain "resolution". Selecting "Detailed Listing" provides links to full-resolution, unstretched, GIF versions of the images.
Io leading hemisphere, scaled to geometric albedo, central longitude 60 W.
Io trailing hemisphere, scaled to geometric albedo, central longitude 263 W.
Europa leading hemisphere, arbitrary reflectance scale, central longitude 81 W.
Ganymede trailing hemisphere, arbitrary reflectance scale, central longitude 252 W.
Callisto leading hemisphere, arbitrary reflectance scale, central longitude 70 W.
Pillan plume, Io, seen with HST: 0.26 - 0.41 microns, July 1997.
HST Press Release of
this image, and other images of Io transiting Jupiter
Adaptive
optics images from ESO by Frank Marchis.
1998 Keck speckle images, 0.02"/pixel (0.04" resolution) at 2.2 microns, showing a transient event near Loki. These are the same pictures Imke de Pater and Seran Gibbard had with them at the DPS. All images are displayed on the same (logarithmic) intensity stretch. The overlaid Io disk is only a rough alignment intended as a guideline; precise image registration is not yet complete. (B. Macintosh, C. Max, D. Gavel, S. Gibbard (LLNL), I. de Pater (UCB).)
<- 98/07/11
<- 98/07/28
<- 98/08/04
Groundbased Adaptive-Optics Image of Io in Eclipse, 2.3 microns
1998/06/03, Christophe Dumas, JPL, Canada-France-Hawaii Telescope (CFHT), Mauna Kea, "Pueo" adaptive optics system. The images were recorded through cirrus and the extinction was very high, about 2 magnitudes. Not too bad considering the conditions! We also have few 1.7 mic images. The adaptive optics system was Pueo, the CFHT system in service since summer 97. The camera was KIR, a 1024x1024 nicmos. Click here for a different stretch of the same image.
Note the remarkable correspondence with the NICMOS image taken six weeks later (below), at a shorter wavelength (but note that the image orientation is different).
HST NICMOS Image of Io in Eclipse, 1.45 microns
J. Goguen, JPL ("First look" comments, 7/30/98), A. Lubenow, A. Storrs, Space Telescope Science Institute
The image on the left is an HST NICMOS image acquired while Io was in Jupiter's shadow on 7/19/98 at 14:44 UT. This 224 second exposure (NIC1, F145M filter, 0.043 arcseconds/pixel, Io diameter is 1.144 arcseconds) of Io's Jupiter-facing hemisphere shows thermal emission from numerous hot spots. The image on the right is a Voyager-based map of Io projected at the same scale and orientation. The dotted circle shows the outline of Io's disk when the brightest source is matched with the known eruption at Loki Patera. The bright and double source at the upper left of the image is in the vicinity of Kanehekili. A faint "diffraction ring" (?) can be seen around the bright sources accounting for the ring which extends beyond the limb near Kanehekili. Note the 2 strong sources at about 10 and 12 o'clock relative to Loki. The source near 10 o'clock appears to correspond to no obvious feature on the Voyager map. The full data set includes 2 micron polarimetry to look for compositional heterogeneity between the hot spots (HST Program #7319).
Voyager-era topographic map of Io.
Global Io topography from Gaskell et al. 1988 (GRL 15, 581), superimposed on
a blue-wavelength Voyager 2 mosaic of Io prepared by Alfred McEwen.
Contour interval 0.5 km, illumination from the upper right.
This was an illustration in the review article by Spencer and
Schneider 1996 (Ann. Rev. Earth. Planet. Sci. 24, 125) but
was mostly destroyed by poor image reproduction.
Io (in eclipse): Keck speckle.
This is a K' speckle image obtained during the September 6, 1996 eclipse
using the 10-m W.M. Keck telescope. The image scale is 0.02 arcseconds per
pixel; resolution is 0.05 arcseconds FWHM. The image is a speckle
reconstruction of 300 exposures, each 0.15 seconds long. Four real sources
are visible - the bright transient 9608A in the center, Kanehekili to the left
and slightly down, a (presumably transient) source above Kanehekili, and a
dim (K'=14.1) source near the east limb. The latitude/longitude grid is
a preliminary registration and only intended as a rough guide. The streaks
extending from the volcanoes are artifacts of the speckle process; the image
has been displayed on a logarithmic scale to show the faintest source.
The image was taken and processed by the LLNL speckle imaging group,
Bruce Macintosh, Don Gavel, Seran Gibbard, and Claire Max, together with
Imke de Pater (UC Berkeley) and Andrea Ghez (UCLA).
Io (in eclipse) passing Europa (in
sunlight): CFHT Adaptive Optics.
97/07/16, 2.26 microns, University of Hawaii
adaptive optics system, Canada-France-Hawaii telescope, Mauna Kea.
Very preliminary reduction: Io has been brightened relative to Europa.
Observers: Christophe Dumas, Francois Roddier, Olivier Hainaut,
Laird Close, Buzz Graves, Malcolm Northcott.
The two bright hot spots on Io are Loki (right) and Kanehekili (left).
Io (in eclipse)
passing Europa (in sunlight): IRTF Direct Imaging.
16:35 UT, 96/04/24, 3.8, 3.5,
and 2.3 microns (R, G, and B respectively), NSFCAM, IRTF (image taken
half an hour after sunrise). Observers: John Stansberry, Christophe
Dumas, and John Spencer.
Io (bottom) is in darkness but shines due to thermal emission from at
least three volcanoes. The brightest is Loki (on the right), the
leftmost, faintest, one is probably Kanehekili, and the lowermost one
is unnamed. Europa (top) is in full sunlight but is extremely dark at
these wavelengths due to absorption of the sunlight by water ice,
especially beyond 3 microns, so it is much bluer than Io, and no
brighter. Europa's disk is clearly resolved and shows a hint of
albedo features (?).
Io (in eclipse)
approaching occultation by Jupiter.
Multiple hot spots are
visible, with overall appearance quite similar to 96/04/24
(above). 15:00 UT, 96/06/02, 3.8 microns, NSFCAM, IRTF. Observers:
Christophe Dumas, John Stansberry, and John Spencer.
Io and its shadow transiting Jupiter, from the
Hubble Space Telescope.
96/07/24, F410M (violet) filter.
Observers: Spencer, McEwen, McGrath, Sartoretti, Nash, Clarke,
Ballester, Trauger. 26K JPEG, 700x600 pixels
The Pele plume seen against Jupiter, from the
Hubble Space Telescope.
96/07/24, F255W and F410M (violet) filter.
Observers: Spencer, McEwen, McGrath, Sartoretti, Nash, Clarke,
Ballester, Trauger. 10K JPEG, 300x300 pixels
