Posts Tagged ‘Io’

Scientists To Io: Your Volcanoes Are In The Wrong Place

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

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

Jupiter’s moon Io is the most volcanically active world in the Solar System, with hundreds of volcanoes, some erupting lava fountains up to 250 miles high. However, concentrations of volcanic activity are significantly displaced from where they are expected to be based on models that predict how the moon’s interior is heated, according to NASA and European Space Agency researchers.

Io is caught in a tug-of-war between Jupiter’s massive gravity and the smaller but precisely timed pulls from two neighboring moons that orbit further from Jupiter – Europa and Ganymede. Io orbits faster than these other moons, completing two orbits every time Europa finishes one, and four orbits for each one Ganymede makes. This regular timing means that Io feels the strongest gravitational pull from its neighboring moons in the same orbital location, which distorts Io’s orbit into an oval shape. This in turn causes Io to flex as it moves around Jupiter.

The question remains regarding exactly how this tidal heating affects the moon’s interior. Some propose it heats up the deep interior, but the prevailing view is that most of the heating occurs within a relatively shallow layer under the crust, called the asthenosphere. The asthenosphere is where rock behaves like putty, slowly deforming under heat and pressure.

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Monitoring Io’s Insane Volcanic Activity From The Comfort Of Earth

October 17, 2012 Leave a comment

Watching active volcanic eruptions should definitely be done from a distance, but a group of California researchers has figured out how to do it from the comfort of home. Using an ingenious combination of Earth-based telescopic surveys and archival data, they have gathered nearly 40 distinct snapshots of effusive volcanic eruptions and high temperature outbursts on Jupiter’s tiny moon, Io, showing details as small as 100 km (60 miles) on the moon’s surface.

Io, the innermost moon of Jupiter, is an insanely active volcanic wonderland. Although the most detailed observations have come from spacecraft, the Galileo Jupiter orbiter mission ended in 2003 and no future mission capable of studying Io is planned until, at the earliest, 2030. However, there will be no large gap in the monitoring of Io’s volcanoes, thanks to the efforts of teams like that led by Franck Marchis, a researcher at the Carl Sagan Center of the SETI Institute. Marchis will present results from ground-based telescopic monitoring of volcanic activity on Io over the past decade at the 2012 DPS Meeting in Reno, Nevada.

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Team Produces 1st Complete Geologic Map of Io

March 19, 2012 1 comment

More than 400 years after Galileo’s discovery of Io, the innermost of Jupiter’s largest moons, a team of scientists led by Arizona State University (ASU) has produced the first complete global geologic map of the Jovian satellite. The map, published by the U. S. Geological Survey, depicts the characteristics and relative ages of some of the most geologically unique and active volcanoes and lava flows ever documented in the Solar System.

Following its discovery by Galileo in January 1610, Io has been the focus of repeated telescopic and satellite scientific observation. These studies have shown that the orbital and gravitational relationships between Io, its sister moons Europa and Ganymede, and Jupiter cause massive, rapid flexing of its rocky crust. These tidal flexures generate tremendous heat within Io’s interior, which is released through the many surface volcanoes observed.

“One of the reasons for making this map was to create a tool for continuing scientific studies of Io, and a tool for target planning of Io observations on future missions to the Jupiter system,” says David Williams, a faculty research associate in the School of Earth and Space Exploration at ASU, who led the six-year research project to produce the geologic map.

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Io’s Volcanism Influences Jupiter’s Magnetosphere

February 1, 2012 Leave a comment

Volcanic emissions from Jupiter’s moon Io supply plasma to the planet’s magnetosphere and lead to its main auroral emissions. New observations show that the main auroral oval expanded and outer emissions brightened in spring 2007. Some studies have suggested that magnetospheric changes such as this could be caused by changes in the incoming solar wind. Bonfond et al. present several lines of evidence—including images from the Hubble Space Telescope and observations of a volcanic plume on Io from the New Horizons probe, along with measurements of increased emissions from Jupiter’s sodium cloud—that indicate that Io’s volcanism controls changes in Jupiter’s magnetosphere.

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