Active Volcanoes of Our Solar System Home » Volcanoes » Active Volcanoes of Our Solar System Active Volcanoes of Our Solar System Activity Occurs on Earth and on the Moons of a Few Planets Volcanoes on Io: Io, a moon of Jupiter, is the most volcanically active body in our solar system. It has over 100 active volcanic centers, many of which have multiple active vents. Eruptions recurrently resurface large parts of the moon. NASA image. Volcanoes Are Not Confined to Earth Evidence of past volcanic activity has been found on most planets in our solar system and on many of their moons. Our own moon has vast areas covered with ancient lava flows. Mars has Olympus Mons and Tharsis Rise, the largest volcanic features in our solar system. The surface of Venus is covered with igneous rocks and hundreds of volcanic features. Most of the volcanic features discovered within our solar system formed millions of years ago - when our solar system was younger and the planets and moons had much higher internal temperatures. Geologically recent volcanic activity is not as widespread. Based upon observations from Earth and from space vehicles, only four bodies in the solar system have confirmed volcanic activity.

These are 1) Earth; 2) Io, a moon of Jupiter; 3) Triton, a moon of Neptune; and, 4) Enceladus, a moon of Saturn. Evidence for possible volcanic activity on Mars , Venus , and Europa has been observed, but no direct eruption observations have been made. What is an Active Volcano? The term "active volcano" is used mainly in reference to Earth's volcanoes. Active volcanoes are ones that are currently erupting or that have erupted at some time in human history. This definition works fairly well for volcanoes on Earth because we can observe some of them easily - but many are located in remote areas where small eruptions could go unnoticed, or below remote parts of the oceans where even large eruptions might not be detected. Beyond Earth, our abilities to detect volcanic eruptions did not begin until the invention of powerful telescopes and made a great leap when space vehicles were able to carry telescopes and other sensing devices close to other planets and their moons. Today a number of telescopes are available to detect these eruptions - if they are large enough and facing in the proper direction.

However, small eruptions might not be noticed because there are not enough telescopes to watch all areas of the solar system where volcanic activity might occur. Although only a few extraterrestrial eruptions have been detected, much has been learned about them. Perhaps the most interesting discovery has been the cryovolcanoes in the outer region of the solar system. Geyser on Enceladus: A color-enhanced view of cryovolcanic activity on Saturn's moon Enceladus. These geysers regularly blast out plumes composed mainly of water vapor with minor amounts of nitrogen, methane, and carbon dioxide. NASA image. What is a Cryovolcano? Most people define the word "volcano" as an opening in Earth's surface through which molten rock material, gases, and ash escape. This definition works well for Earth; however, some bodies in our solar system have a significant amount of gas in their composition. Planets near the sun are rocky and produce silicate rock magmas similar to those seen on Earth. However, planets beyond Mars and their moons contain significant quantities of gas in addition to silicate rocks. The volcanoes in this part of our solar system are usually cryovolcanoes.

Instead of erupting molten rock, they erupt cold or frozen gases such as water, ammonia, or methane. Io Tvashtar volcano: This five-frame animation produced using images captured by the New Horizons spacecraft illustrates a volcanic eruption on Io, a moon of Jupiter. The eruption plume is estimated to be about 180 miles high. NASA image. Jupiter's Moon Io - The Most Active Io is the most volcanically active body in our solar system. This surprises most people because Io's great distance from the sun and its icy surface make it seem like a very cold place. However, Io is a very tiny moon that is enormously influenced by the gravity of the giant planet Jupiter. The gravitational attraction of Jupiter and its other moons exert such strong "pulls" on Io that it deforms continuously from strong internal tides. These tides produce a tremendous amount of internal friction. This friction heats the moon and enables the intense volcanic activity. Io has hundreds of volcanic vents, some of which blast jets of frozen vapor and "volcanic snow" hundreds of miles high into its atmosphere. These gases could be the sole product of these eruptions, or there could be some associated silicate rock or molten sulfur present.

The areas around these vents show evidence that they have been "resurfaced" with a flat layer of new material. These resurfaced areas are the dominant surface feature of the moon. The very small number of impact craters compared to other bodies in the solar system is evidence of Io's continuous volcanic activity and resurfacing. Volcanic eruption on Io: Image of one of the largest eruptions ever observed on Jupiter's moon, Io, taken on August 29, 2013 by Katherine de Kleer of the University of California at Berkeley using the Gemini North Telescope. This eruption is thought to have launched hot lava hundreds of miles above Io's surface. More information . "Curtains of Fire" on Io On August 4, 2014 NASA published images of volcanic eruptions that occurred on Jupiter's moon Io between August 15 and August 29 of 2013. During that two-week period, eruptions powerful enough to launch material hundreds of miles above the surface of the moon are believed to have occurred. Other than Earth, Io is the only body in the solar system that is capable of erupting extremely hot lava.

Because of the moon's low gravity and the magma's explosivity, large eruptions are believed to launch tens of cubic miles of lava high above the moon and resurface large areas over a period of just a few days. The accompanying infrared image shows the August 29, 2013 eruption and was acquired by Katherine de Kleer of the University of California at Berkeley using the Gemini North Telescope, with support from the National Science Foundation. It is one of the most spectacular images of volcanic activity ever taken. At the time of this image, large fissures in Io's surface are believed to have been erupting "curtains of fire" up to several miles long. Cryovolcano mechanics: Diagram of how a cryovolcano might work on Io or Enceladus. Pockets of pressurized water a short distance below the surface are heated by internal tidal action. When pressures become high enough, they vent to the surface. Triton - The First Discovered Triton was the first location in the solar system where cryovolcanoes were observed. The Voyager 2 probe observed plumes of nitrogen gas and dust up to five miles high during its 1989 flyby.

These eruptions are responsible for Triton's smooth surface because the gases condense and fall back to the surface, forming a thick blanket similar to snow. Some researchers believe that solar radiation penetrates the surface ice of Triton and heats a dark layer below. The entrapped heat vaporizes subsurface nitrogen, which expands and eventually erupts through the ice layer above. This would be the only known location of energy from outside of a body causing an eruption - the energy usually comes from within. Cryovolcano on Enceladus: An artist's vision of what a cryovolcano might look like on the surface of Enceladus, with Saturn visible in the background. NASA image. Enlarge . Enceladus - The Best Documented Cryovolcanoes on Enceladus were documented by the Cassini spacecraft in 2005. The spacecraft imaged jets of icy particles venting from the south polar region. This made Enceladus the fourth body in the solar system with confirmed volcanic activity. The spacecraft actually flew through a cryovolcanic plume and documented its composition to be mainly water vapor with minor amounts of nitrogen, methane, and carbon dioxide.

One theory for the mechanism behind the cryovolcanism is that subsurface pockets of pressurized water exist a short distance (perhaps as little as a few tens of meters) beneath the moon's surface. This water is kept in the liquid state by the tidal heating of the moon's interior. Occasionally these pressurized waters vent to the surface, producing a plume of water vapor and ice particles. Evidence for Activity The most direct evidence that can be obtained to document volcanic activity on extraterrestrial bodies is to see or image the eruption taking place. Another type of evidence is a change in the body's surface. An eruption can produce a ground cover of debris or a resurfacing. Volcanic activity on Io is frequent enough and the surface is visible enough that these types of changes can be observed. Without such direct observations, it can be difficult from Earth to know if the volcanism is recent or ancient. Will More Activity be Discovered? Cryovolcanoes on Enceladus were not discovered until 2005, and an exhaustive search has not been done across the solar system for this type of activity.

In fact, some believe that volcanic activity on our close neighbor Venus still occurs but is hidden beneath the dense cloud cover. A few features on Mars suggest possible recent activity there. It is also very likely, perhaps probable, that active volcanoes or cryovolcanoes will be discovered on moons of icy planets in the outer portions of our solar system such as Europa , Titan, Dione, Ganymede, and Miranda. This is an exciting time to watch space exploration! A Moon With The Most Volcanic Activity Of Anything In The Solar System A Moon With The Most Volcanic Activity Of Anything In The Solar System Go to permalink This moon looks even more like it's made from green cheese than ours does, but it's not. Lame. Io , the innermost moon of Jupiter, is the most volcanically active body in our solar system because of gravitational "tides" exerted by Jupiter and its other moons. And the constantly flowing lava gives Io's surface frequent makeovers. Advertisement This image was created with data from NASA's Galileo spacecraft collected in 1996. I0's appearance has presumably changed a lot since then, but there are still cool things to notice in this image.

For example, there aren't any craters visible on Io's surface (all those pits and holes are volcanoes) so the ash deposits and lava flowing across the surface must fill or cover craters more quickly than they are created. This image also depicts the side of Io that always faces away from Jupiter, providing a look at the dark side of the moon. Sort of. [ Astronomy Picture of the Day ] Gear from Kinja Deals Io: Facts about Jupiter’s Volcanic Moon Io: Facts about Jupiter’s Volcanic Moon By Kim Ann Zimmermann | June 16, 2016 03:23pm ET MORE This is a montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the spacecraft’s Jupiter flyby . The image was released in Oct. 2007. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute Jupiter’s fifth moon, Io, is the most volcanically active body in the solar system. Plumes of sulfur spew upward as high as 190 miles (300 kilometers). The surface of Io is splotched with lava lakes and floodplains of liquid rock.

Io by the numbers Age: Io is about 4.5 billion years old, about the same age as Jupiter . Distance from Jupiter: Io is the fifth moon from Jupiter. Its orbital distance is about 262,000 miles (422,000 km). Io takes 1.77 Earth-days to orbit Jupiter. Io is tidally locked, so the same side always faces Jupiter. Size: Io has a mean radius of 1,131.7 miles, making it slightly larger than Earth’s moon. It has a slight elliptical shape, with its longest axis directed toward Jupiter. Among the Galilean satellites Io ranks third, behind Ganymede and Callisto but ahead of Europa , in both mass and volume. Temperature: Io's surface temperature averages about minus 202 degrees Fahrenheit (minus 130 Celsius), resulting in the formation of sulfur dioxide snowfields. But Io’s volcanoes can reach 3,000 F (1,649 C). Io is often referred to as a celestial body of fire and ice. The Discovery of Io Artist's concept of the internal structure of Jupiter's moon Io.

A global magma "ocean" (shown in orange) lies beneath a crust 30 to 50 kilometers thick. The rest of Io's mantle is shown in gold, while the moon's core is rendered in silver. Credit: Xianzhe Jia (University of Michigan) and Krishan Khurana (UCLA) Io was the first of Jupiter’s moons discovered by Galileo Galilei on Jan. 8, 1610. He actually discovered the moon the day prior, but could not differentiate between Io and Europa, another Jupiter moon, until the next night. The discovery, along with three other Jovian moons, was the first time a moon was discovered orbiting a planet other than Earth. Galileo’s discovery eventually led to the understanding that planets orbit the sun, instead of our solar system revolving around Earth. Galileo first referred to this moon as Jupiter I. In the mid-1800s, the moon was renamed Io. In Greek mythology, Io was a priestess of Hera (Zeus' wife) and the daughter of Inachus, the king of Argos.

Zeus (the counterpart for the Roman god Jupiter) fell in love with her, but turned her into a cow to avoid being caught with her by his wife, Hera (or Juno). Several spacecraft have flown by Jupiter and its moons. Pioneer 10 arrived first, in 1973, followed by Pioneer 11 in 1974. Voyager 1 and Voyager 2 returned striking photos during their flybys. The Galileo spacecraft passed as low as 162 miles (261 km) over the surfaces of the Galilean moons and produced detailed images. Characteristics of Io Hubble Space Telescope ultraviolet image of the northern pole of Jupiter. Among many other auroral structures, the Io footprint is the most equator-ward feature close to the centre of the image. This spot is always located close to the feet of the magnetic field lines connected to the satellite Io. Credit: LPAP/Université de Liège The interior of Io is composed of an iron or iron sulfide core and a brown silicate outer layer, giving the planet a splotchy orange, yellow, black, red, and white appearance.

Based on data from scientific computer models, Io formed in a region around Jupiter where water ice was plentiful. Io’s heat, combined with the possibility that there was water on Io shortly after it was formed, could have made life possible, although Jupiter’s radiation would have removed the water from the surface. The moon's most distinctive features are its volcanoes. Aside from Earth, Io is the only known body in the solar system to have observed active volcanoes. While Galileo had made some cryptic notes inferring possible volcanic activity, NASA's Voyager spacecraft discovered Io's volcanoes in 1979. The volcanic activity is a result of Io being stretched and squeezed as it orbits Jupiter. Io's rock surface bulges up and down by as much as 100 meters (328 feet) during the process. This affects Io’s volcanic activity in a similar way to which Earth’s oceans react to the moon. Io’s irregularly elliptical orbit also heightens the tidal activity. Because of the volcanic activity, Io’s atmosphere contains mostly sulphur dioxide. Io’s orbit cuts across Jupiter’s powerful magnetic lines of force, turning Io into an electric generator.

As Jupiter rotates, the magnetic forces strip away about a ton (1,000 kg) of Io’s material every second. The material becomes ionized and forms a doughnut-shaped cloud of radiation called a plasma torus. Some of the ions are pulled into Jupiter’s upper atmosphere and create auroras . Explosive mysteries Io's environment has come under intense scrutiny in recent years as scientists try to explain why the moon has the most active volcanoes in the solar system. The recent findings involve both observations of the moon and modeling of the interior, which can only be inferred. A 2015 study explained why Io's most prolific volcanoes appear to be offset from where scientists expected they would be. While previous models suggested that the zones with the most intense heating would have more active volcanoes, the actual Io had its most active ones farther east. The study suggests that if there was an ocean mixed with molten and solid rock underneath the moon, the rock portions would rub against each other and create the offset zones scientists observed. Insights into Io's surface may also come from a 2012 map published by the U.S. Geological Survey – the first to include the entire surface.

The researchers said that volcanic activity would be among the things that could be studied with this map. The imagery includes observations from the Voyager 1 and Voyager 2 spacecraft, as well as Galileo. While there is no mission specifically planned to look at Io, there will be other missions in the vicinity of the moon in future years, including Juno (2016), a planned NASA Europa mission (perhaps in the 2030s), and the European Space Agency's JUICE mission (JUpiter ICy Moons Explorer, which will focus on Europa, Ganymede and Callisto). Meanwhile, observations continue from the ground; sometimes Io's volcanoes are violent enough to produce spectacular pictures even from so far away . Additional reporting by contributor Elizabeth Howell. This map, released in March 2012 by the U.S. Geological Survey, is the first ever to chart the Jupiter moon Io's geology on a global scale. Io is the most volcanically active object in the solar system.

Credit: USGS Jupiter's Moon Io: Solar System's Most Volcanically Active Body - Kids Discover by KIDS DISCOVER Share Io, the third largest moon of Jupiter, is the most volcanically active body in our solar system. When the Voyager 1 spacecraft took the first close-ups of Io in 1979, it revealed that this moon, which is only a little larger than Earth’s moon, was covered with active volcanoes — more than 400! Jupiter’s four largest moons are called the Galilean moons, because they were all discovered by the famous scientist Galileo Galilei. Two of them, Ganymede and Europa, exert forces on Io’s orbit that make it travel in a lopsided ellipse. According to NASA, Io is also subjected to intense tidal forces due to its widely varying distances from the planet. These forces create “tides” that are similar to those of Earth’s oceans, but way more extreme — and on solid ground, not water! In fact, unlike its fellow Galilean moons, Io appears to have no water.

While Io’s fiery volcanic plumes can rise to almost 200 miles above the surface, the moon also generates a huge amount of electricity as it cuts through Jupiter’s magnetic field. This creates lightning in the planet’s upper atmosphere. Galileo discovered Io and the other three Galilean moons over two days in January 1610. He didn’t name them after himself; that came later. He originally dubbed them the “Medicean planets” after the rich and powerful Medici family, who supported his work. Galileo didn’t even name the individual moons, but only numbered them I, II, III, and IV. They didn’t get their current names — all taken from figures in Greek mythology — until the mid-1800s. In Galileo’s time, people believed that the solar system revolved around Earth. His discovery marked the first time anyone had observed a moon orbiting another planet besides Earth, and it helped lead scientists to conclude that planets in our solar system orbit the sun. About the author KIDS DISCOVER For over 25 years, we’ve been creating beautifully crafted nonfiction products for kids.

With a specialty in science and social studies, our team of talented writers, award-winning designers and illustrators, and subject-experts from leading institutions is committed to a single mission: to get children excited about reading and learning. You May Also Like I'm a Homeschooler Newsletter Sign Up Sign up for our email list and gain access to free content, special promotions, sales and more. Volcanoes in the Solar System 4-11 Jun: Nyiragongo Lava Lake & Mountain Gorillas - DR Congo + Rwanda : spaces available / : guaranteed / : few spaces left / : booked out Random pictures Jupiter's moon Io, photographed by the Voyager 1 spacecraft. Io is the volcanically most active body of the Solar System. Eruptions occur as a result of intense tidal forces exerted by Jupiter's gravity. It has more than 100 active volcanoes with hundreds of active vents. Io's frequent eruptions repeatedly resurface large parts of its surface. (image NASA / GPL) Active volcanoes in the Solar System The Earth is not the only place with volcanic activity in our Solar System.

Although there are significant differences in the type and style of volcanic activity from that on Earth, several other planets and moons have or had in the geologic past volcanic activity as well: Currently, there there are 4 known bodies of our Solar System with still active volcanic activity: 1) Our Earth 2) Io, a moon of Jupiter 3) Triton, a moon of Neptune 4) Enceladus, a moon of Saturn Mars, Venus and the Jupiter moon Europa might still have volcanic activity as well, but there have been no direct observations of eruptions as evidence so far. Most volcanism outside Earth seems to have occurred in the early ages of the Solar System, when the planets were still hotter: our moon had volcanic activity in the remote geologic past, between 3-4 billion years ago, when it still was hot enough to allow basaltic lava flows to erupt through the broken crust of impact craters, the maars. Mount Olympus on Mars is the largest known volcano in the entire Solar System, Venus is dotted with thousands of volcanic features, and Io is the volcanically most active place in the System. Most of the knowledge of volcanic activity outside Earth comes from recent space research using modern telescopes and space craft.

Jupiter Jupiter's atmosphere is made up mostly of hydrogen (H2) and helium (He). Many Moons Jupiter has 53 known moons, with an additional 14 moons awaiting confirmation of their discovery -- that is a total of 67 moons. Ringed World Jupiter has a faint ring system that was discovered in 1979 by the Voyager 1 mission. All four giant planets in our solar system have ring systems. Exploring Jupiter Many missions have visited Jupiter and its system of moons. The Juno spacecraft is currently orbiting Jupiter. Ingredients for Life? Jupiter cannot support life as we know it. However, some of Jupiter's moons have oceans underneath their crusts that might support life. Did You Know? Jupiter's Great Red Spot is a gigantic storm (about the size of Earth) that has been raging for hundreds of years. Jupiter: In Depth Jupiter is the fifth planet from our sun and the largest planet in the solar system. Jupiter's stripes and swirls are cold, windy clouds of ammonia and water. The atmosphere is mostly hydrogen and helium, and its iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years.

Jupiter is surrounded by 53 confirmed moons, as well as 14 provisional ones — for a possible total of 67 moons. Scientists are most interested in the "Galilean satellites" — the four largest moons discovered by Galileo Galilei in 1610: Europa, Callisto, Ganymede and Io. Jupiter also has three rings, but they are very hard to see and not nearly as intricate as Saturn's. Jupiter is named for the king of ancient Roman gods. Jupiter compared to Earth. Image Token: Size and Distance With a radius of 43,440.7 miles (69,911 kilometers), Jupiter is 11 times wider than Earth. If Earth were the size of a nickel, Jupiter would be about as big as a basketball. From an average distance of 484 million miles (778 million kilometers), Jupiter is 5.2 astronomical units away from the sun. One astronomical unit (abbreviated as AU), is the distance from the sun to Earth. From this distance, it takes sunlight 43 minutes to travel from the sun to Jupiter. Orbit and Rotation Jupiter has the shortest day in the solar system.

One day on Jupiter takes only about 10 hours (the time it takes for Jupiter to rotate or spin around once), and Jupiter makes a complete orbit around the sun (a year in Jovian time) in about 12 Earth years (4,333 Earth days). Its equator is tilted with respect to its orbital path around the sun by just 3 degrees. This means Jupiter spins nearly upright and does not have seasons as extreme as other planets do. Formation Jupiter took shape when the rest of the solar system formed about 4.5 billion years ago, when gravity pulled swirling gas and dust in to become this gas giant. Jupiter took most of the mass left over after the formation of the sun, ending up with more than twice the combined material of the other bodies in the solar system. In fact, Jupiter has the same ingredients as a star, but it did not grow massive enough to ignite. About 4 billion years ago, Jupiter settled into its current position in the outer solar system, where it is the fifth planet from the sun. Structure The composition of Jupiter is similar to that of the sun — mostly hydrogen and helium. Deep in the atmosphere, pressure and temperature increase, compressing the hydrogen gas into a liquid.

This gives Jupiter the largest ocean in the solar system — an ocean made of hydrogen instead of water. Scientists think that, at depths perhaps halfway to the planet's center, the pressure becomes so great that electrons are squeezed off the hydrogen atoms, making the liquid electrically conducting like metal. Jupiter's fast rotation is thought to drive electrical currents in this region, generating the planet's powerful magnetic field. It is still unclear if, deeper down, Jupiter has a central core of solid material or if it may be a thick, super-hot and dense soup. It could be up to 90,032 degrees Fahrenheit (50,000 degrees Celsius) down there, made mostly of iron and silicate minerals (similar to quartz). Surface As a gas giant, Jupiter doesn't have a true surface. The planet is mostly swirling gases and liquids. While a spacecraft would have nowhere to land on Jupiter, it wouldn't be able to fly through unscathed either. The extreme pressures and temperatures deep inside the planet crush, melt and vaporize spacecraft trying to fly into the planet. Atmosphere Jupiter's Great Red Spot trapped between two powerful jet streams. Image Token: Jupiter's appearance is a tapestry of colorful cloud bands and spots.

The gas planet likely has three distinct cloud layers in its "skies" that, taken together, span about 44 miles (71 kilometers). The top cloud is probably made of ammonia ice, while the middle layer is likely made of ammonium hydrosulfide crystals. The innermost layer may be made of water ice and vapor. The vivid colors you see in thick bands across Jupiter may be plumes of sulfur and phosphorus-containing gases rising from the planet's warmer interior. Jupiter's fast rotation — spinning once every 10 hours — creates strong jet streams, separating its clouds into dark belts and bright zones across long stretches. With no solid surface to slow them down, Jupiter's spots can persist for many years. Stormy Jupiter is swept by over a dozen prevailing winds, some reaching up to 335 miles per hour (539 kilometers per hour) at the equator. The Great Red Spot, a swirling oval of clouds twice as wide as Earth, has been observed on the giant planet for more than 300 years. More recently, three smaller ovals merged to form the Little Red Spot, about half the size of its larger cousin.

Scientists do not yet know if these ovals and planet-circling bands are shallow or deeply rooted to the interior. Potential for Life Jupiter's environment is probably not conducive to life as we know it. The temperatures, pressures and materials that characterize this planet are most likely too extreme and volatile for organisms to adapt to. While planet Jupiter is an unlikely place for living things to take hold, the same is not true of some of its many moons. Europa is one of the likeliest places to find life elsewhere in our solar system. There is evidence of a vast ocean just beneath its icy crust, where life could possibly be supported. Moons With four large moons and many smaller moons, Jupiter forms a kind of miniature solar system. Jupiter has 53 confirmed moons, as well as 14 provisional ones — for a possible total of 67 moons. These newly discovered, provisional moons are reported by astronomers and acknowledged with a temporary designation by the International Astronomical Union. Once their orbits are confirmed, they are included in Jupiter's confirmed moon count.

Jupiter's four largest moons — Io, Europa, Ganymede and Callisto — were first observed by the astronomer Galileo Galilei in 1610 using an early version of the telescope. These four moons are known today as the Galilean satellites, and they're some of the most fascinating destinations in our solar system. Io is the most volcanically active body in the solar system. Ganymede is the largest moon in the solar system (even bigger than the planet Mercury). Callisto's very few small craters indicate a small degree of current surface activity. A liquid-water ocean with the ingredients for life may lie beneath the frozen crust of Europa, making it a tempting place to explore. Rings Discovered in 1979 by NASA's Voyager 1 spacecraft, Jupiter's rings were a surprise, as they are composed of small, dark particles and are difficult to see except when backlit by the sun. Data from the Galileo spacecraft indicate that Jupiter's ring system may be formed by dust kicked up as interplanetary meteoroids smash into the giant planet's small innermost moons. Magnetosphere The Jovian magnetosphere is the region of space influenced by Jupiter's powerful magnetic field.

It balloons 600,000 to 2 million miles (1 to 3 million kilometers) toward the sun (seven to 21 times the diameter or Jupiter itself) and tapers into a tadpole-shaped tail extending more than 600 million miles (1 billion kilometers) behind Jupiter, as far as Saturn's orbit. Jupiter's enormous magnetic field is 16 to 54 times as powerful as that of the Earth. It rotates with the planet and sweeps up particles that have an electric charge. Near the planet, the magnetic field traps swarms of charged particles and accelerates them to very high energies, creating intense radiation that bombards the innermost moons and can damage spacecraft. Jupiter's magnetic field also causes some of the solar system's most spectacular aurorae at the planet's poles. Exploration While Jupiter has been known since ancient times, the first detailed observations of this planet were made by Galileo Galilei in 1610 with a small telescope. More recently, this planet has been visited by passing spacecraft, orbiters and probes.

Pioneer 10 and 11 and Voyager 1 and 2 were the first to fly by Jupiter in the 1970s, and since then we've sent Galileo to orbit the gas giant and drop a probe into its atmosphere. Cassini took detailed photos of Jupiter on its way to neighboring Saturn, as did New Horizons on its quest for Pluto and the Kuiper Belt. The next mission is Juno, which arrived in the Jovian system in July 2016. How Jupiter Got its Name The largest and most massive of the planets was named Zeus by the Greeks and Jupiter by the Romans; he was the most important deity in both pantheons. The symbol for Jupiter is said to represent a hieroglyph of the eagle, Jove's bird, or to be the initial letter of Zeus with a line drawn through it to indicate its abbreviation. Significant Dates 1610: Galileo Galilei makes the first detailed observations of Jupiter. 1973: Pioneer 10 becomes the first spacecraft to cross the asteroid belt and fly past Jupiter.

1979: Voyager 1 and 2 discover Jupiter's faint rings, several new moons and volcanic activity on Io's surface. 1992: Ulysses swung by Jupiter on Feb. 8, 1992. The giant planet's gravity bent the spacecraft's flight path southward and away from the ecliptic plane, putting the probe into a final orbit that would take it over the sun's south and north poles. 1994: Astronomers observe as pieces of comet Shoemaker-Levy 9 collide with Jupiter's southern hemisphere. 1995-2003: The Galileo spacecraft drops a probe into Jupiter's atmosphere and conducts extended observations of Jupiter and its moons and rings. 2000: Cassini makes its closest approach to Jupiter at a distance of approximately 6.2 million miles (10 million kilometers), taking a highly detailed true color mosaic photo of the gas giant. 2007: Images taken by NASA's New Horizons spacecraft, on the way to Pluto, show new perspectives on Jupiter's atmospheric storms, the rings, volcanic Io, and icy Europa.

2009: On 20 July, almost exactly 15 years after fragments of comet Shoemaker-Levy slammed into Jupiter, a comet or asteroid crashes into the giant planet's southern hemisphere. 2011: Juno launches to examine Jupiter's chemistry, atmosphere, interior structure and magnetosphere. 2016: NASA's Juno spacecraft arrives at Jupiter, conducting an in-depth investigation of the planet's atmosphere, deep structure and magnetosphere for clues to its origin and evolution. Pop Culture The biggest planet in our solar system, Jupiter also has a large presence in pop culture, including many movies, TV shows, video games and comics. Jupiter was a notable destination in the Wachowski siblings' science fiction spectacle Jupiter Ascending, while various Jovian moons provide settings for Cloud Atlas, Futurama, Power Rangers, and Halo, among many others. In Men in Black when Agent J — played by Will Smith — mentions he thought one of his childhood teachers was from Venus, Agent K — played by Tommy Lee Jones — replies that she is actually from one of Jupiter's moons. Jupiter: Trivia Jumpin' Jupiter There are no rockets powerful enough to hurl a spacecraft into the outer solar system and beyond.

In 1962, scientists calculated how to use Jupiter's intense gravity to hurl spacecraft into the farthest regions of the solar system. We've been traveling farther and faster ever since. Comet Collision Comets break up all the time, but it's rare for a comet to be captured in Jupiter's orbit and even more unusual for the comet to crash into the giant planet. Humans first witnessed one of these cosmic collisions in 1994. Hail to the King Jupiter is by far the largest of the planets. If it were hollow, more than 1,300 Earths could fit inside of it. The giant planet contains two-thirds of all the planetary mass in the solar system and holds more than dozens of moons in its gravitational grip. Family Reunion Every so often Jupiter's moons, Io, Ganymede and Callisto cross in front of their parent planet at the same time. This rare alignment, known as a triple eclipse, happens only once or twice a decade. Second Sun? Gas giant Jupiter's composition is similar to a small star -- mostly hydrogen and helium. But it never grew large enough to trigger the fusion reaction that would have given our solar system a second sun.

The Hot Zone Jupiter is not a people-friendly place. Radiation levels encountered by spacecraft visiting Jupiter are more than 1,000 times the lethal level for a human. Even heavily-shielded spacecraft like Galileo were damaged by the radiation. Mighty Moon With a diameter of 3,270 miles (5,262 km) Jupiter's Ganymede is the largest moon in our solar system -- bigger even than planet Mercury and dwarf planet Pluto. Storm of the Centuries Jupiter's Great Red Spot is about as big as Earth. The hurricane-like storm is at least 300 years old. Volcano Moon Jupiter's moon Io is the most volcanically active body in our solar system. Active volcanoes constantly spew material onto Io's surface. Jupiter: Moons 13. S/2011 J1 14. S/2011 J2 Jupiter has 53 named moons. Fourteen more have been discovered but not given official status or names. Combined, scientists now think Jupiter has 67 moons. There are many interesting moons orbiting the planet, but the ones of most scientific interest are the first four moons discovered beyond Earth - the Galilean satellites.

The planet Jupiter's four largest moons are called the Galilean satellites after Italian astronomer Galileo Galilei, who first observed them in 1610. The German astronomer Simon Marius claimed to have seen the moons around the same time, but he did not publish his observations and so Galileo is given the credit for their discovery. These large moons, named Io, Europa, Ganymede, and Callisto, are each distinctive worlds. Io is the most volcanically active body in the solar system. Io's surface is covered by sulfur in different colorful forms. As Io travels in its slightly elliptical orbit, Jupiter's immense gravity causes "tides" in the solid surface that rise 100 m (300 feet) high on Io, generating enough heat for volcanic activity and to drive off any water. Io's volcanoes are driven by hot silicate magma. Europa's surface is mostly water ice, and there is evidence that it may be covering an ocean of water or slushy ice beneath. Europa is thought to have twice as much water as does Earth.

This moon intrigues astrobiologists because of its potential for having a "habitable zone." Life forms have been found thriving near subterranean volcanoes on Earth and in other extreme locations that may be analogues to what may exist on Europa. Ganymede is the largest moon in the solar system (larger than the planet Mercury), and is the only moon known to have its own internally generated magnetic field. Callisto's surface is extremely heavily cratered and ancient -- a visible record of events from the early history of the solar system. However, the very few small craters on Callisto indicate a small degree of current surface activity. The interiors of Io, Europa and Ganymede have a layered structure (as does Earth). Io has a core, and a mantle of at least partially molten rock, topped by a crust of solid rock coated with sulfur compounds. Europa and Ganymede both have a core; a rock envelope around the core; a thick, soft ice layer; and a thin crust of impure water ice. In the case of Europa, a global subsurface water layer probably lies just below the icy crust. Layering at Callisto is less well defined and appears to be mainly a mixture of ice and rock.

Three of the moons influence each other in an interesting way. Io is in a tug-of-war with Ganymede and Europa, and Europa's orbital period (time to go around Jupiter once) is twice Io's period, and Ganymede's period is twice that of Europa. In other words, every time Ganymede goes around Jupiter once, Europa makes two orbits and Io makes four orbits. The moons all keep the same face towards Jupiter as they orbit, meaning that each moon turns once on its axis for every orbit around Jupiter. Pioneers 10 and 11 (1973 to 1974) and Voyager 1 and Voyager 2 (1979) offered striking color views and global perspectives from their flybys of the Jupiter system. From 1995 to 2003, the Galileo spacecraft made observations from repeated elliptical orbits around Jupiter, passing as low as 261 km (162 miles) over the surfaces of the Galilean moons. These close approaches resulted in images with unprecedented detail of selected portions of the surfaces.

Close-up images taken by the Galileo spacecraft of portions of Europa's surface show places where ice has broken up and moved apart, and where liquid may have come from below and frozen smoothly on the surface. The low number of craters on Europa leads scientists to believe that a subsurface ocean has been present in recent geologic history and may still exist today. The heat needed to melt the ice in a place so far from the sun is thought to come from inside Europa, resulting primarily from the same type of tidal forces that drive Io's volcanoes. Jupiter: Rings A cut away view of Jupiter's ring system and the small moons that help create it. Unlike the brilliant, icy rings of Saturn, Jupiter's rings are delicate, dusty structures. And while Saturn's beautiful rings were first spotted in 1610, Jupiter's faint rings were not discovered until 1979 when NASA's Voyager 1 spacecraft flew close to Jupiter. We now know all four giant planets of our solar system have rings. Jupiter's ring system has three main components: a pair of very faint outer rings called the gossamer rings; a wide, flat main ring; and a thick inner ring called the halo.

The rings appear to be created by dust thrown off by impacts on small moons. The gossamer rings are bounded by the orbits of the moons Amalthea and Thebe. Adrastea and Metis skirt the outer edges of the main ring. Sources Io Moon Facts The colorful Jupiter moon Io, the most volcanically active body in the solar system Io Facts Io is the fifth moon in distance from the planet Jupiter. It orbits Jupiter at an average distance of 262,000 miles (422,000 km,) similar to the distance the Moon orbits Earth. Io is the third largest of Jupiter's moons and very similar in size to our own moon. It is the most volcanically active object in the solar system. Volcanic plumes rise almost 190 miles (300 km) above the surface. Io has an iron core just like Earth, meaning it could have its own magnetic field. The moon's orbit cuts across Jupiter's powerful magnetic field producing 400,000 volts of electricity across its surface. Jupiter's magnetic field strips off 1 ton of material from Io every second!

The moon was discovered in January 1610 by the Italian astronomer Galileo Galilei. Io is often compared to a pizza due to its unusual surface which is made up of sulfur dioxide deposits. A giant plume erupting from Io's northern polar Tvashtar volcano Io's Surface Jupiter's huge gravity causes Io's surface to bulge up and down by as much as 100 meters! This also generates tremendous heat inside Io, turning its subsurface into liquid. This molten lava frequently escapes causing its surface to constantly change. Io's Atmosphere Io's atmosphere is roughly 1 millionth as dense as Earth's atmosphere and made primarily of sulfur. Io's Temperature Temperatures on Io vary from extremely hot to extremely cold. Areas which feature volcanic activity can reach temperatures of over 2000C (4000F). Away from these areas however will see temperatures plunge to -143C (-230F). Origin of Name Io is named from Greek mythology after the priestess of Hera who became a lover of Zeus. Life on Io Io is an extremely hostile environment with little or no chance for the existence of life.

Io - The Volcanic Moon The spectacular surface of Io with volcanic plume As Voyager 1 and 2 approached the Jupiter system in the late 1970's NASA scientists fully expected the craft to discover that its moons would be cold, dead and not particularly interesting, instead what they found was quite astonishing. One moon in particular stood out, Io, scientists were amazed to find out that it was in fact geologically active with volcanoes constantly erupting on its surface. The sulfur deposits from the eruptions also made the small moon strikingly colorful. Scientists initially scratched their heads and wondered how a small moon in one of the coldest parts of the solar system could be generating so much heat. The explanation was in fact very simple, Io's orbit around Jupiter is extremely elliptical, meaning that sometimes it's close to the giant planet and other times it's further away. This causes Jupiter’s strong gravity to push and pull the small moon, producing immense heat inside Io and creating molten lava below its surface. Scientists had expected to find something similar to our moon but what they had in fact discovered was the most geologically active body in the entire solar system.

Missions to Io Launch: 2020 Agency: NASA/ESA Summary: A joint venture by NASA and the ESA (Europe) will study Io using two separate spacecraft. Even though they will be focusing mainly on another of Jupiter's moons Europa, they will make four close flybys of Io. Juno Summary: Will provide monitoring of Io's volcanic activity using its near-infrared spectrometer. New Horizons Arrival: January 2007 Agency: NASA Summary: During its flyby of the Jovain system New Horizons captured spectacular images of Io including the eruption of its north polar volcano. Galileo Arrival: December 1995 Agency: NASA Summary: During its study of the Jovian system Galileo sent back a lot of new data on Io. Including the discovery of several active volcanoes on the moon, the existence of an iron core, and significant changes to the surface since the earlier Voyager missions. Voyager 1 and 2 Arrival: April-August 1979 Agency: NASA Summary: As part of its "Grand Tour" of the solar system Voyager 1 and 2 took high resolution images of Io revealing an oddly multi colored moon with a curiously craterless surface.

After the images were sent back to Earth a young female engineer noticed a plume emanating from the surface on one of the pictures proving that Io was volcanically active. Pioneer 10 and 11 Launch: March 1972 - April 1973 Arrival: December 1973 - December 1974 Agency: NASA Summary: The first spacecrafts to explore the outer solar system. They provided little data on Io apart from a better estimate of its mass. Pioneer 11 managed to take only one image of any quality pictured left. Share this page Io: Jupiter’s Volcanic Moon – Worst Smell in the Solar System | Video Io: Jupiter’s Volcanic Moon – Worst Smell in the Solar System | Video By Clayton Ashley | September 28, 2012 03:31pm ET Tidal forces of Jupiter's huge mass cause sulphur volcanoes of Jupiter's inner most moon to constantly erupt. Io is literally tearing itself apart. It's the most geologically active body in the solar system.

credit : Space.com APOD: 2012 April 8 - Io: Moon Over Jupiter Io: Moon Over Jupiter Image Credit: Cassini Imaging Team , SSI , JPL , ESA , NASA Explanation: How big is Jupiter's moon Io ? The most volcanic body in the Solar System, Io (usually pronounced "EYE-oh") is 3,600 kilometers in diameter, about the size of planet Earth's single large natural satellite . Gliding past Jupiter at the turn of the millennium, the Cassini spacecraft captured this awe inspiring view of active Io with the largest gas giant as a backdrop, offering a stunning demonstration of the ruling planet's relative size . Although in the above picture Io appears to be located just in front of the swirling Jovian clouds, Io hurtles around its orbit once every 42 hours at a distance of 420,000 kilometers or so from the center of Jupiter . That puts Io nearly 350,000 kilometers above Jupiter's cloud tops , roughly equivalent to the distance between Earth and Moon . The Cassini spacecraft itself was about 10 million kilometers from Jupiter when recording the image data.

Savage Earth: Other Planets Volcanoes on Other Planets by Kathy Svitil Just as it has on Earth, volcanism has played a powerful role in shaping other worlds in our solar system. "Venus, for example, is covered with volcanoes, and many of them are clearly geologically very young," says Alfred McEwen, a planetary scientist at the University of Arizona. Planetary probes have never picked up a clear sign of volcanic activity there, but, back in 1978, astronomers on Earth spotted a strange brightening in the planet's northern hemisphere. Many thought it might be an eruption. That same year, the Pioneer spacecraft detected high levels of sulfur dioxide, a volcanic gas. The Magellan spacecraft (1989-1994) detected hundreds of volcanoes on the surface of Venus. Although it is likely that Venus is currently volcanically active, no conclusive evidence of present-day eruptions has yet been observed. Mars also has many distinctively volcanic features, including the largest volcano in the solar system, Olympus Mons, which towers 16 miles high over the Martian landscape.

"If volcanism had occurred up until the last 1% of geologic time, it is very unlikely to have stopped," McEwen says. "We just haven't observed anything that is a smoking gun on either Mars or Venus." Volcanoes also shaped Mercury. There, however, the activity appears to have stopped operating early in the planet's history, billions of years ago. On our moon, too, volcanism operated early and then shut off sometime around 3 billion years ago. On Jupiter's moon Europa, which has a fractured outer surface of ice (under which may lie an ocean), volcanism may still be operating, although probes have yet to detect the tell-tale signs of a volcanic eruption. "Although it is pure speculation, there could be silicate volcanism transmitted through the water," McEwen says. Another possibility, McEwen says, is ice volcanism. "A plume of water vapor or a water flow in the surface is considered a volcanic fluid if it is heated and warmed up by the internal heat of the moon," McEwen says. Some researchers have also suggested that the same sort of ice volcanism may be present on Saturn's moon, Enceladus.

Another moon of Saturn's, Titan, may also be volcanic (which would explain the satellite's dense atmosphere), as may be Neptune's moon, Triton. Io, one of Jupiter's moons. Planetary scientists have no doubt that Jupiter's moon Io is volcanically active. In fact, the satellite -- which is about the size of our own moon -- is the most volcanically active body in the solar system. Recent images obtained by NASA's Galileo spacecraft have revealed about 100 active volcanic centers, each comprised of many calderas (large volcanic depressions in the ground), says McEwen, who heads the Galileo Io imaging team. As many as 500 volcanic centers may have been active in the last 100 years. Io's calderas (craters) are remarkably hot. "Our temperature measurements indicate hotter temperatures than any active volcanism on Earth," McEwen says. "It implies that the magma is magnesium-rich -- comparable to the mantle composition of the Earth. This is what happened on Earth during the Archean era, 2.5 billion years ago, when the Earth was hotter. That's interesting, because it suggests that we might learn something about ancient volcanoes on Earth by studying Io today."

Question: Which moon of Jupiter is the most volcanic body in our Solar System?
Answer: IO