New Geologic Map Reveals Solar System's Most Volcanic World

Geologic map of Jupiter moon, Io
Geologic map of Jupiter moon, Io

U.S astronomers have created the first complete geologic map of Jupiter’s highly volcanic moon, Io.

With 425 volcanoes dotting its surface, Io is more than 25 times more volcanically active than the Earth, yet this innermost of Jupiter's larger satellites is only slightly bigger than our Moon.

Io's varied surface features include mountains, volcanic domes, plains, and lava lakes.  The Arizona State University astronomers say the new full-color map shows the location and concentration of the most active hot spots and lava fields on the surface - information that will help scientists better understand the moon's interior processes.

Astronomers believe Io's extreme volcanic activity is caused by the powerful tidal forces exerted by Jupiter - the solar system's most massive planet - and two of its 62 other confirmed moons, Europa and Ganymede.   Their combined gravitational pull stretches and bends Io’s rocky crust, generating tremendous heat in the interior that is released through hundreds of volcanoes.  The extreme seismic activity continuously changes the moon's surface, which explains why Io is the only rocky object in the solar system without any impact craters.

Six years in the making, the new map is a composite of four separate image mosaics comprised of observations made by NASA's twin Voyager spacecraft and the Jupiter orbiter, Galileo.  

But the astronomers say they are not done yet.  

Later this year, they plan to complete an on-line database that will include the geologic map of Io, plus the original image mosaics, and other Galileo spacecraft observations.   The researchers say the database will allow users to track the history of surface changes on Io caused by volcanic activity.  

The map of Io is published on the U.S. Geological Survey website.

The 17th century Italian astronomer, Galileo, discovered Io and three other moons of Jupiter in 1610.   Now known as the Galilean moons, the four lunar siblings are: Io, Callisto, Ganymede, and Europa.

This forum has been closed.
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Hungary Criticized for Handling of Refugeesi
Henry Ridgwell
October 08, 2015 8:02 PM
Amnesty International has accused Hungary of breaking multiple international and European human rights laws in its handling of the refugee crisis. As Henry Ridgwell reports, thousands of migrants and refugees continue to travel through the Balkans to Hungary every day.

Video Hungary Criticized for Handling of Refugees

Amnesty International has accused Hungary of breaking multiple international and European human rights laws in its handling of the refugee crisis. As Henry Ridgwell reports, thousands of migrants and refugees continue to travel through the Balkans to Hungary every day.

Video Iraqi-Kurdish Teachers Vow to Continue Protest

Sixteen people were injured when police used tear gas and rubber bullets to disperse teachers and other public employees who took to the streets in Iraq’s Kurdish north, demanding their salaries from the Kurdish Regional Government (KRG). VOA’s Dilshad Anwar, in Sulaimaniya, caught up with protesting teachers who say they have not been paid for three months. Parke Brewer narrates his report.

Video Syrian Village Community Faces Double Displacement in Lebanon

Driven by war from their village in southwestern Syria, a group of families found shelter in Lebanon, resettling en masse in a half-built university to form one of the biggest settlements of its kind in Lebanon. Three years later, however, they now face being kicked out and dispersed in a country where finding shelter as a refugee can be especially tough. John Owens has more for VOA from the city of Saida, also known as Sidon.

Video Bat Colony: Unusual Tourist Attraction in Texas

The action hero Batman might be everyone’s favorite but real bats hardly get that kind of adoration. Put more than a million of these creatures of the night together and it only evokes images of horror. Sarah Zaman visited the largest urban bat colony in North America to see just how well bat and human get along with each other.

Video Device Shows Promise of Stopping Motion Sickness

It’s a sickening feeling — the dizziness, nausea and vomiting that comes with motion sickness. But a device now being developed could stop motion sickness by suppressing certain signals in the brain. VOA’s Deborah Block reports.

Video Making a Mint

While apples, corn, and cranberries top the list of fall produce in the US, it’s also the time to harvest gum, candy, and toothpaste—or at least the oil that makes them minty fresh. Erika Celeste reports from South Bend, Indiana on the mint harvest.

Video Activists Decry Lagos Slum Demolition

Acting on a court order, authorities in Nigeria demolished a slum last month in the commercial capital, Lagos. But human rights activists say the order was illegal, and the community was razed to make way for a government housing project. Chris Stein has more from Lagos.

Video TPP Agreed, But Faces Stiff Opposition

President Barack Obama promoted the Trans-Pacific Partnership on Tuesday, one day after 12 Pacific Rim nations reached the free trade deal in Atlanta. The controversial pact that would involve about 40 percent of global trade still needs approval by lawmakers in respective countries. Zlatica Hoke reports Obama is facing strong opposition to the deal, including from members of his own party.

Video Ukranian Artist Portrays Putin in an Unusual Way

As Russian President Vladimir Putin was addressing the United Nations in New York last month, he was also being featured in an art exhibition in Washington. It’s not a flattering exhibit. It’s done by a Ukrainian artist in a unique medium. And its creator says it’s not only a work of art - it’s a political statement. VOA’s Tetiana Kharchenko has more.

Video Nano-tech Filter Cleans Dirty Water

Access to clean water is a problem for hundreds of millions of people around the world. Now, a scientist and chemical engineer in Tanzania (in East Africa) is working to change that by creating an innovative water filter that makes dirty water safe. VOA’s Deborah Block has the story.

Video Demand Rising for Organic Produce in Cambodia

In Cambodia, where rice has long been the main cash crop, farmers are being encouraged to turn to vegetables to satisfy the growing demand for locally produced organic farm products. Daniel de Carteret has more from Phnom Penh.

Video Botanists Grow Furniture, with Pruning Shears

For something a bit out of the ordinary to furnish your home, why not consider wooden chairs, crafted by nature, with a little help from some British botanists with an eye for design. VOA’s Jessica Berman reports.

VOA Blogs