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A R C H I V E S

This dramatic image of Io was taken by the Long Range Reconnaissance Imager (LORRI) onboard the NASA - New Horizons Probe at 11:04 Universal Time on February 28, of the AD 2007, just about 5 hours after the Spacecraft's closest approach to Jupiter. The distance from Io, at the time that the picture was taken, was approx. 2,5 Million Kilometers (such as about 1,5 Million Miles) and the image is centered at 85° West Longitude. At this distance, one LORRI pixel subtends approx. 12 Km (such as about 7,4 miles) of the Surface of Io. This processed image provides the best view yet of the enormous - approx. 290-Kilometer (about 180-miles) high - Plume from the Volcano Tvashtar, visible in the 11 o'clock direction near Io's North Pole.

The Plume was first seen by the Hubble Space Telescope and then by the NASA - New Horizons Probe on February 26, 2007; as a matter of fact, this image is way clearer than the February 26 one, because of several factors: first of all, because Io, in this second situation, was closer to the Spacecraft; second, because the Plume was more backlit by the Sun, and, last but not least, because a longer Exposure Time (such as 75 milliseconds versus 20 milliseconds) was used.

Io's Day Side was deliberately overexposed in this picture so to image the fainter Plumes, and the long exposure also provided us with an excellent view of Io's Night Side, as illuminated by Jupiter (actually, and just to be precise, as it was illuminated by the so-called "Jupitershine"). The remarkable Filamentary Structure well visible in the Tvashtar Plume is substantially similar to some details (glimpsed faintly in the AD 1979 by a few NASA - Voyager 1 and 2 Probes' images) of another Volcanic Plume which, in that occasion, had been produced by Io's Volcano, Pele. However, no previous image by any Spacecraft has shown these mysterious structures so clearly. This frame also shows the much smaller symmetrical fountain of the Plume, about 60 Km (or approx. 40 miles) high, emanating from the Prometheus Volcano (visible on Io's Limb, in the 9 o'clock position).

The top of a third Volcanic Plume, this one coming from from the Volcano Masubi, erupts high enough to catch the setting Sun on the Night Side (see near the bottom of the image, at about 6 o'clock, and appearing as an irregular bright patch against Io's Jupiter-lit Surface). Several Everest-sized Mountains are highlighted by the setting Sun along the Terminator (such as the line dividing the day from the night) of Io. This is the last of a handful of LORRI images that the NASA - New Horizons Probe is sending "home" during its busy close encounter with Jupiter - hundreds of images and other data are being taken and stored onboard. The rest of the images will be returned to Earth over the coming weeks and months as the Spacecraft speeds along to Pluto.

This picture has been colorized in (Enhanced) Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - New Horizons Probe and then looked outside, towards the Jovian moon Io), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.