Europa Remastered

The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution.

The view was previously released as a mosaic with lower resolution and strongly enhanced color (see PIA02590). To create this new version, the images were assembled into a realistic color view of the surface that approximates how Europa would appear to the human eye.

The scene shows the stunning diversity of Europa's surface geology. Long, linear cracks and ridges crisscross the surface, interrupted by regions of disrupted terrain where the surface ice crust has been broken up and re-frozen into new patterns.

Color variations across the surface are associated with differences in geologic feature type and location. For example, areas that appear blue or white contain relatively pure water ice, while reddish and brownish areas include non-ice components in higher concentrations. The polar regions, visible at the left and right of this view, are noticeably bluer than the more equatorial latitudes, which look more white. This color variation is thought to be due to differences in ice grain size in the two locations.

Images taken through near-infrared, green and violet filters have been combined to produce this view. The images have been corrected for light scattered outside of the image, to provide a color correction that is calibrated by wavelength. Gaps in the images have been filled with simulated color based on the color of nearby surface areas with similar terrain types.

This global color view consists of images acquired by the Galileo Solid-State Imaging (SSI) experiment on the spacecraft's first and fourteenth orbits through the Jupiter system, in 1995 and 1998, respectively. Image scale is 1 mile (1.6 kilometers) per pixel. North on Europa is at right.

Image credit: NASA/JPL-Caltech/SETI Institute

Note: For more information, see NASA Issues 'Remastered' View of Jupiter's Moon Europa.

Comet Shoemaker-Levy 9 Fragment W Impact With Jupiter

These four images of Jupiter and the luminous night-side impact of fragment W of Comet Shoemaker-Levy 9 were taken by the Galileo spacecraft on July 22, 1994. The spacecraft was 238 million kilometers (148 million miles) from Jupiter at the time, and 621 million kilometers from Earth. The spacecraft was about 40 degrees from Earth's line of sight to Jupiter, permitting this direct view. The images were taken at intervals of 2 1/3 seconds, using the green filter (visible light). The first image, taken at an equivalent time to 8:06:10 Greenwich Mean Time (1:06 a.m. Pacific Daylight Time), shows no impact. In the next three images, a point of light appears, brightens so much as to saturate its picture element, and then fades again, seven seconds after the first picture. The location is approximately 44 degrees south as predicted, dark spots to the right are from previous impacts. Jupiter is approximately 60 picture elements in diameter.

Image credit: NASA/JPL

Note: For more information, see Looking Back at the Jupiter Crash 20 Years Later.

Reddish Bands on Europa

This colorized image of Europa is a product of clear-filter grayscale data from one orbit of NASA's Galileo spacecraft, combined with lower-resolution color data taken on a different orbit. The blue-white terrains indicate relatively pure water ice, whereas the reddish areas contain water ice mixed with hydrated salts, potentially magnesium sulfate or sulfuric acid. The reddish material is associated with the broad band in the center of the image, as well as some of the narrower bands, ridges, and disrupted chaos-type features. It is possible that these surface features may have communicated with a global subsurface ocean layer during or after their formation.

Part of the terrain in this previously unreleased color view is seen in the monochrome image, PIA01125.

The image area measures approximately 101 by 103 miles (163 km by 167 km). The grayscale images were obtained on November 6, 1997, during the Galileo spacecraft's 11th orbit of Jupiter, when the spacecraft was approximately 13,237 miles (21,700 kilometers) from Europa. These images were then combined with lower-resolution color data obtained in 1998, during the spacecraft's 14th orbit of Jupiter, when the spacecraft was 89,000 miles (143,000 km) from Europa.

Image credit: NASA/JPL-Caltech/SETI Institute

Ganymede Geological Map

Animation of a rotating globe of Jupiter's moon Ganymede, with a geologic map superimposed over a global color mosaic. The 37-second animation begins as a global color mosaic image of the moon then quickly fades in the geologic map.

The views incorporate the best available imagery from NASA's Voyager 1 and 2 spacecraft and NASA's Galileo spacecraft.

To present the best information in a single view of Jupiter's moon Ganymede, a global image mosaic was assembled, incorporating the best available imagery from NASA's Voyager 1 and 2 spacecraft and NASA's Galileo spacecraft. This image shows Ganymede centered at 200 west longitude. This mosaic (right) served as the base map for the geologic map of Ganymede (left).

Video credit (top): USGS Astrogeology Science Center/Wheaton/ASU/NASA/JPL-Caltech; image credit (bottom): USGS Astrogeology Science Center/Wheaton/NASA/JPL-Caltech

Note: For more information, see Largest Solar System Moon Detailed in Geologic Map.

Water Vapor from Europa

This graphic shows the location of water vapor detected over Europa's south pole in observations taken by NASA's Hubble Space Telescope in December 2012. This is the first strong evidence of water plumes erupting off Europa's surface.

Hubble didn't photograph plumes, but spectroscopically detected auroral emissions from oxygen and hydrogen. The aurora is powered by Jupiter's magnetic field. This is only the second moon in the solar system found ejecting water vapor from the frigid surface. The image of Europa is derived from a global surface map generated from combined observations taken by NASA's Voyager and Galileo space probes.

Image credit: NASA/ESA/L. Roth/SWRI/University of Cologne

Note: For more information, see Hubble Discovers Water Vapor Venting from Jupiter's Moon Europa, PIA17659: Artist's Concept of Europa Water Vapor Plume, and Hubble Sees Evidence of Water Vapor at Jupiter Moon.

Energy From Above Affecting Surface of Europa

This graphic of Jupiter's moon Europa maps a relationship between the amount of energy deposited onto the moon from charged-particle bombardment and the chemical contents of ice deposits on the surface in five areas of the moon (labeled A through E).

Energetic ions and electrons tied to Jupiter's powerful magnetic field smack into Europa as the field sweeps around Jupiter. The magnetic field travels around Jupiter even faster than Europa orbits the planet. Most of the energetic particles hitting Europa strike the moon's "trailing hemisphere," the half facing away from the direction Europa travels in its orbit. The "leading hemisphere," facing in the direction of travel, receives fewer of the charged particles.

Researchers assessed the amount of sulfate hydrates -- compared with relatively pristine water -- in the surface ice in five widely distributed areas of Europa. They used data from observations made by the near infrared spectrometer (NIMS) instrument on NASA's Galileo spacecraft, which orbited Jupiter from 1995 to 2003. They found that the concentration of frozen sulfuric acid on the surface varies greatly. It ranges from undetectable levels near the center of Europa's leading hemisphere, to more than half of the surface material near the center of the trailing hemisphere. The concentration is closely related to the amount of energy received from electrons and sulfur ions striking the surface, with a distribution controlled by interactions between Jupiter and Europa's magnetic fields.

This pattern could provide direction for the best places to study the surface of Europa for learning about material churned up from the moon's subsurface, which includes a deep saltwater ocean beneath an icy shell. The portions of the surface least affected by the bombardment of charged particles from above are most likely to preserve the original chemical compounds that erupted from the interior. Understanding the chemical ingredients of Europa's subsurface ocean could help scientists determine whether, as many suspect, the ocean could have supported life in the past or even now.

The images of Europa used for the base maps of this figure were taken by the solid state imager on Galileo. The areas labeled A through E are the areas covered by five sets of NIMS observations, and color-coded with darker, bluer portions having more sulfate hydrates and brighter, pinker portions having more water ice. The mapped patterns for energy input are derived from models for the flux of electrons and ions delivered by Jupiter's magnetic field. The color-code key at the right is labeled in units of mega electron volts per square centimeter per second.

Image Credit: NASA/JPL-Caltech/University of Arizona/JHUAPL/University of Colorado

Note: For more information, see Where are the Best Windows Into Europa's Interior?

Europa

This view of Jupiter's moon Europa features several regional-resolution mosaics overlaid on a lower resolution global view for context. The regional views were obtained during several different flybys of the moon by NASA's Galileo mission, and they stretch from high northern to high southern latitudes. Prominent here are the long, arcuate (or arc-shaped) and linear markings called lineae (Latin for strings or threads), which are a signature feature of Europa's surface. Color saturation has been enhanced to bring out the subtle red coloration present along many of the lineae. The color data extends into the infrared, showing bluish ice (indicating larger ice grains) in the polar regions.

The terrain in this view stretches from the side of Europa that always trails in its orbit at left (west), to the side that faces away from Jupiter at right (east). In addition to the lineae, the regional-scale images contain many interesting features, including lenticulae (small spots), chaos terrain, maculae (large spots), and the unusual bright band known as Agenor Linea in the south.

The regional-resolution mosaics enhance the amount of detail visible in a previously released view of the same region on Europa, [see PIA02590]. While the earlier image uses much of the same low-resolution data, its images are projected from a different angle and are processed with greater color saturation.

This view is an orthographic projection centered on 5.53 degrees south latitude, 214.5 degrees west longitude and has a resolution of 1600 feet (500 meters) per pixel. An orthographic view is like the view seen by a distant observer looking through a telescope.

The mosaic was constructed from individual images obtained by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during six flybys of Europa between 1996 and 1999 (flybys designated G1, E11, E14, E15, E17, and E19).

Image credit: NASA/JPL-Caltech/University of Arizona

Note: For more new information on Europa, see A Window into Europa's Ocean Right at the Surface, PIA16826: Taste of the Ocean on Europa's Surface (Artist's Concept) and Long-stressed Europa Likely Off-kilter at One Time.

Io

This is the highest resolution color picture taken so far [as of that date] of Jupiter's volcanic moon Io by NASA's Galileo spacecraft. At 3 kilometers (about 2 miles) per picture element, the fiery satellite is seen against a backdrop of Jupiter's cloud tops, which appear blue in this false-color composite. Among the surprises seen on the moon's surface are several small, distinctly greenish patches and subtle violet hues at the cores and margins of bright sulfur dioxide-rich regions (like the one in the lower right). Dark spots, many flagged by bright red pyroclastic deposits, (deposits from explosive ejecta), mark the sites of current volcanic activity. Most of Io's riotous color is due to the presence of sulfur compounds, but the dark materials that make up the flows and calderas are probably silicate rock.

North is to the top of the picture. The images used to construct this composite were taken in the 1-micron, green and violet filters of the solid state imaging camera system on NASA's Galileo spacecraft. The images were taken on March 29, 1998 at a range of 294,000 kilometers (about 183,000 miles).

Photo credit: NASA/JPL/University of Arizona