Showing posts with label Infrared Astronomy. Show all posts
Showing posts with label Infrared Astronomy. Show all posts

Saturday, November 22, 2014

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.

Thursday, December 12, 2013

Clay Minerals on Europa


This image, using data from NASA's Galileo mission, shows the first detection of clay-like minerals on the surface of Jupiter's moon Europa. The clay-like minerals appear in blue in the false-color patch of data from Galileo's Near-Infrared Mapping Spectrometer. Surfaces richer in water ice appear in red. The background image is a mosaic of images from Galileo's Solid State Imaging system in the colors that human eyes would see.

Scientists think an asteroid or comet impact could have delivered the clay-type minerals to Europa because these minerals are commonly found in these primitive celestial bodies. These kinds of asteroids and comets also typically carry organic compounds.

A version of the image without the infrared area is on the right.

Image credit: NASA/JPL-Caltech

Note: For more information, see PIA17657: Hit Hard: Possible Collision at Europa (Artist's Concept) and Clay-Like Minerals Found on Icy Crust of Europa.

Tuesday, November 26, 2013

Cracks and Ridges on Europa


This enhanced color image shows cracks and ridges on Europa's surface that reveal a detailed geologic history. Some ridges, such as the prominent one at top right, develop into long, arc-shaped "cycloids" that may be related to changing tidal forces as Europa orbits Jupiter. The wall of this ridge stands perhaps a third of a mile (0.5 kilometer) above the surrounding ridged plains, although the edges are likely not as steep as they appear in this view.

The view was captured by NASA's Galileo spacecraft on February 2, 1999, during its E19 orbit, when the spacecraft was about 2500 miles (4000 km) from the surface of Europa. Resolution in the scene is 295 feet (90 meters) per pixel. North is toward bottom left. Images taken through near-infrared, green and violet filters were combined to create the view.

Image credit: NASA/JPL-Caltech

Wednesday, April 24, 2013

Distribution of Water in Jupiter's Stratosphere


This map shows the distribution of water in the stratosphere of Jupiter as measured with ESA's Herschel space observatory. White and cyan indicate highest concentration of water, and blue indicates lesser amounts. The map has been superimposed over an image of Jupiter taken at visible wavelengths with the NASA/ESA Hubble Space Telescope.

The distribution of water clearly shows an asymmetric distribution across the planet's disc: water is more abundant in the southern hemisphere. Based on this and other clues collected with Herschel, astronomers have established that at least 95 per cent of the water currently present in Jupiter's stratosphere has been supplied by comet Shoemaker-Levy 9, which famously impacted the planet at intermediate southern latitudes in 1994.

The map is based on spectrometric data collected with the PACS instrument on board Herschel around 66.4 microns, a wavelength that corresponds to one of water's many spectral signatures.

Image credit: Water map: ESA/Herschel/T. Cavalié et al.; Jupiter image: NASA/ESA/Reta Beebe (New Mexico State University)

Note: For more information, see Herschel Links Water in Stratosphere to 1994 Comet Impact and Herschel Links Water Around Jupiter to Comet Impact.

Saturday, April 13, 2013

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?

Saturday, April 6, 2013

Europa in Natural and Enhanced Colors


This color composite view combines violet, green, and infrared images of Jupiter's intriguing moon, Europa, for a view of the moon in natural color (left) and in enhanced color designed to bring out subtle color differences in the surface (right). The bright white and bluish part of Europa's surface is composed mostly of water ice, with very few non-ice materials. In contrast, the brownish mottled regions on the right side of the image may be covered by hydrated salts and an unknown red component. The yellowish mottled terrain on the left side of the image is caused by some other unknown component. Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long.

North is to the top of the picture and the sun fully illuminates the surface. Europa is about 3,160 kilometers (1,950 miles) in diameter, or about the size of Earth's moon. The finest details that can be discerned are 25 kilometers across. The images in this global view were taken in June 1997 at a range of 1.25 million kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft, during its ninth orbit of Jupiter.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see Mapping the Chemistry Needed for Life at Europa.

Wednesday, March 6, 2013

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.

Thursday, December 30, 2010

Acetylene at Jupiter's North and South Poles



These images and movie show the distribution of the organic molecule acetylene at the north and south poles of Jupiter, based on data obtained by NASA's Cassini spacecraft in early January 2001. It is the highest-resolution map of acetylene to date on Jupiter. The enhanced emission results both from the warmer temperatures in the auroral hot spots, and probably also from an enhanced abundance in these regions. The detection helps scientists understand the chemical interactions between sunlight and molecules in Jupiter's stratosphere.

These maps were made by NASA's composite infrared spectrometer.


Photo and video credit: NASA/JPL/GSFC

Friday, October 8, 2010

Jupiter and Io, by New Horizons



This is a montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the spacecraft’s Jupiter flyby [pdf] in early 2007. The Jupiter image is an infrared color composite taken by the spacecraft’s near-infrared imaging spectrometer, the Linear Etalon Imaging Spectral Array (LEISA) at 1:40 UT on February 28, 2007. The infrared wavelengths used (red: 1.59 µm, green: 1.94 µm, blue: 1.85 µm) highlight variations in the altitude of the Jovian cloud tops, with blue denoting high-altitude clouds and hazes, and red indicating deeper clouds. The prominent bluish-white oval is the Great Red Spot. The observation was made at a solar phase angle of 75 degrees but has been projected onto a crescent to remove distortion caused by Jupiter’s rotation during the scan. The Io image, taken at 00:25 UT on March 1st 2007, is an approximately true-color composite taken by the panchromatic Long-Range Reconnaissance Imager (LORRI), with color information provided by the 0.5 µm (“blue”) and 0.9 µm (“methane”) channels of the Multispectral Visible Imaging Camera (MVIC). The image shows a major eruption in progress on Io’s night side, at the northern volcano Tvashtar. Incandescent lava glows red beneath a 330-kilometer high volcanic plume, whose uppermost portions are illuminated by sunlight. The plume appears blue due to scattering of light by small particles in the plume.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute