Jupiter's moon Io saw three massive volcanic eruptions within a two-week period last August. This August 29, 2013, outburst on Io was among the largest ever observed on the most volcanically active body in the solar system. The infrared was image taken by Gemini North telescope, courtesy of Katherine de Kleer, UC Berkeley.
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).
Jupiter's four largest satellites, including Io, the golden ornament in front of Jupiter in this image from NASA's Cassini spacecraft, have fascinated Earthlings ever since Galileo Galilei discovered them in 1610 in one of his first astronomical uses of the telescope. This true-color composite frame, made from narrow angle images taken on December 12, 2000, captures Io and its shadow in transit against the disk of Jupiter. The distance of the spacecraft from Jupiter was 19.5 million kilometers. The image scale of the high resolution image is 117 kilometers per pixel. The entire body of Io, about the size of Earth's Moon, is periodically flexed as it speeds around Jupiter and feels, as a result of its non-circular orbit, the periodically changing gravitational pull of the planet. The heat arising in Io's interior from this continual flexure makes it the most volcanically active body in the solar system, with more than 100 active volcanoes. The white and reddish colors on its surface are due to the presence of different sulfurous materials. The black areas are silicate rocks.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research InstituteThis 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 Feb. 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.
