Juno spots most extreme volcanic activity on Io to date


Gray sphere with grid lines. Patches and dots of very bright light on it, with one very bright near the pole.
This image, taken by the Jovian Infrared Auroral Mapper (JIRAM) infrared imager aboard NASA’s Juno spacecraft on December 27, 2024, highlights volcanic activity on Io, one of Jupiter’s moons. A massive hotspot – larger than Earth’s Lake Superior – can be seen just to the right of Io’s south pole. Image via NASA/ JPL-Caltech/ SwRI/ ASI/ INAF/ JIRAM.
  • Jupiter’s moon Io is highly volcanically active, with around 400 volcanoes on its surface.
  • On its most recent flyby of Io, NASA’s Juno spacecraft detected the most intense volcanic activity ever seen on the Jovian moon.
  • The eruption likely left long-term signatures on Io, which Juno will investigate during an upcoming flyby.

NASA published this original article on January 28, 2025. Edits by EarthSky.

Extreme volcanic activity on Io

During a flyby of Jupiter’s moon Io on December 27, 2024, NASA’s Juno spacecraft discovered an astonishing volcanic hotspot in the moon’s southern hemisphere. The hotspot is not only larger than Earth’s Lake Superior (the largest freshwater lake in the world by surface area), but it also belches out eruptions with six times the total energy of all the world’s power plants. Even by Io’s intense standards – as the most volcanic celestial body in the solar system – its recent activity has been extreme.

Juno’s principal investigator Scott Bolton of the Southwest Research Institute in San Antonio, Texas, said:

The data from this latest flyby really blew our minds. This is the most powerful volcanic event ever recorded on the most volcanic world in our solar system; so that’s really saying something.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Half a tan-colored sphere with dozens of small, round dark spots on it.
The Juno spacecraft acquired this closeup image of Io on December 30, 2023. It was its 57th perijove, or close flyby to Jupiter, since entering orbit around the giant planet on July 4, 2016. Some of the pockmarks are active volcanos. Image via NASA.

Io: A tormented, volcanic world

The source of Io’s torment is Jupiter. Io is about the size of Earth’s moon, and orbits extremely close to the mammoth gas giant. And it whips around Jupiter once every 42.5 hours in an elliptical (oval-shaped) orbit. As the distance to Jupiter varies, so does the planet’s gravitational pull, which leads to the moon being relentlessly squeezed.

The result: immense energy from frictional heating. This melts portions of Io’s interior, resulting in a seemingly endless series of lava plumes and ash venting into its atmosphere from the estimated 400 volcanoes that riddle its surface.

Juno’s close flybys reveal volcanic activity on Io

The discovery of this recent activity comes courtesy of Juno’s Jovian Infrared Auroral Mapper (JIRAM) instrument, contributed by the Italian Space Agency. Designed to capture the infrared light (which isn’t visible to the human eye) emerging from deep inside Jupiter, JIRAM has probed the gas giant’s weather layer, peering 30 to 45 miles (48 to 72 kilometers) below its cloud tops. But since NASA extended Juno’s mission, the team has also used the instrument to study the moons Io, Europa, Ganymede, and Callisto.

During its extended mission, Juno’s trajectory passes by Io every other orbit, flying over the same part of the moon each time. Previously, the spacecraft made close flybys of Io in December 2023 and February 2024, getting within about 930 miles (1,500 kilometers) of its surface. The latest flyby took place on December 27, 2024, bringing the spacecraft within about 46,200 miles (74,400 kilometers) of the moon, with the infrared instrument trained on Io’s southern hemisphere.

Red sphere, partly in shadow, on black background. There are many small, very bright spots on its surface.
View larger. | Juno captured this stunning infrared view of Io and its many volcanoes on July 5, 2022. Image via NASA/ JPL-Caltech/ SwRI/ ASI/ INAF/ JIRAM.

Io brings the heat

Alessandro Mura, a Juno co-investigator from the National Institute for Astrophysics in Rome, said:

JIRAM detected an event of extreme infrared radiance — a massive hotspot — in Io’s southern hemisphere, so strong that it saturated our detector. However, we have evidence what we detected is actually a few closely spaced hotspots that emitted at the same time, suggestive of a subsurface vast magma chamber system. The data support that this is the most intense volcanic eruption ever recorded on Io.

The JIRAM science team estimates the as-yet-unnamed feature spans 40,000 square miles (100,000 square kilometers). The previous record holder was Io’s Loki Patera, a lava lake of about 7,700 square miles (20,000 square kilometers). The total power value of the new hotspot’s radiance measured well above 80 trillion watts.

Three images of a rusty brown and white moon. Purple arrows point to the same spot on each.
Images of Io captured in 2024 by the JunoCam imager aboard NASA’s Juno show significant and visible surface changes (indicated by the arrows) near the Jovian moon’s south pole. These changes occurred between the 66th and 68th perijove (the point during Juno’s orbit when it is closest to Jupiter). Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Jason Perry.

Volcanic activity on Io leaves a mark

The feature was also captured by the mission’s JunoCam visible light camera. The team compared JunoCam images from the two previous Io flybys with those the instrument collected on December 27. And while these most recent images are of lower resolution since Juno was farther away, the relative changes in surface coloring around the newly discovered hotspot are clear. Such changes in Io’s surface are known to be associated with hotspots and volcanic activity.

An eruption of this magnitude is likely to leave long-lived signatures. Other large eruptions on Io have created varied features, such as pyroclastic deposits (composed of rock fragments spewed out by a volcano), small lava flows that may be fed by fissures, and volcanic-plume deposits rich in sulfur and sulfur dioxide.

Juno will use an upcoming, more distant flyby of Io on March 3 to look at the hotspot again and search for changes in the landscape. Earth-based observations of this region of the moon may also be possible.

Bolton said:

While it is always great to witness events that rewrite the record books, this new hotspot can potentially do much more. The intriguing feature could improve our understanding of volcanism not only on Io but on other worlds as well.

Bottom line: On its most recent flyby, the Juno spacecraft spotted intense volcanic activity on Io, one of Jupiter’s moons. It was the most extreme volcanism ever seen on Io.

Via NASA

Read more: Io’s raging volcanoes are self-powered

Read more: Lava lakes on Io: Juno zooms in on Io’s volcanoes

The post Juno spots most extreme volcanic activity on Io to date first appeared on EarthSky.



from EarthSky https://ift.tt/OSvIwsc
Gray sphere with grid lines. Patches and dots of very bright light on it, with one very bright near the pole.
This image, taken by the Jovian Infrared Auroral Mapper (JIRAM) infrared imager aboard NASA’s Juno spacecraft on December 27, 2024, highlights volcanic activity on Io, one of Jupiter’s moons. A massive hotspot – larger than Earth’s Lake Superior – can be seen just to the right of Io’s south pole. Image via NASA/ JPL-Caltech/ SwRI/ ASI/ INAF/ JIRAM.
  • Jupiter’s moon Io is highly volcanically active, with around 400 volcanoes on its surface.
  • On its most recent flyby of Io, NASA’s Juno spacecraft detected the most intense volcanic activity ever seen on the Jovian moon.
  • The eruption likely left long-term signatures on Io, which Juno will investigate during an upcoming flyby.

NASA published this original article on January 28, 2025. Edits by EarthSky.

Extreme volcanic activity on Io

During a flyby of Jupiter’s moon Io on December 27, 2024, NASA’s Juno spacecraft discovered an astonishing volcanic hotspot in the moon’s southern hemisphere. The hotspot is not only larger than Earth’s Lake Superior (the largest freshwater lake in the world by surface area), but it also belches out eruptions with six times the total energy of all the world’s power plants. Even by Io’s intense standards – as the most volcanic celestial body in the solar system – its recent activity has been extreme.

Juno’s principal investigator Scott Bolton of the Southwest Research Institute in San Antonio, Texas, said:

The data from this latest flyby really blew our minds. This is the most powerful volcanic event ever recorded on the most volcanic world in our solar system; so that’s really saying something.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Half a tan-colored sphere with dozens of small, round dark spots on it.
The Juno spacecraft acquired this closeup image of Io on December 30, 2023. It was its 57th perijove, or close flyby to Jupiter, since entering orbit around the giant planet on July 4, 2016. Some of the pockmarks are active volcanos. Image via NASA.

Io: A tormented, volcanic world

The source of Io’s torment is Jupiter. Io is about the size of Earth’s moon, and orbits extremely close to the mammoth gas giant. And it whips around Jupiter once every 42.5 hours in an elliptical (oval-shaped) orbit. As the distance to Jupiter varies, so does the planet’s gravitational pull, which leads to the moon being relentlessly squeezed.

The result: immense energy from frictional heating. This melts portions of Io’s interior, resulting in a seemingly endless series of lava plumes and ash venting into its atmosphere from the estimated 400 volcanoes that riddle its surface.

Juno’s close flybys reveal volcanic activity on Io

The discovery of this recent activity comes courtesy of Juno’s Jovian Infrared Auroral Mapper (JIRAM) instrument, contributed by the Italian Space Agency. Designed to capture the infrared light (which isn’t visible to the human eye) emerging from deep inside Jupiter, JIRAM has probed the gas giant’s weather layer, peering 30 to 45 miles (48 to 72 kilometers) below its cloud tops. But since NASA extended Juno’s mission, the team has also used the instrument to study the moons Io, Europa, Ganymede, and Callisto.

During its extended mission, Juno’s trajectory passes by Io every other orbit, flying over the same part of the moon each time. Previously, the spacecraft made close flybys of Io in December 2023 and February 2024, getting within about 930 miles (1,500 kilometers) of its surface. The latest flyby took place on December 27, 2024, bringing the spacecraft within about 46,200 miles (74,400 kilometers) of the moon, with the infrared instrument trained on Io’s southern hemisphere.

Red sphere, partly in shadow, on black background. There are many small, very bright spots on its surface.
View larger. | Juno captured this stunning infrared view of Io and its many volcanoes on July 5, 2022. Image via NASA/ JPL-Caltech/ SwRI/ ASI/ INAF/ JIRAM.

Io brings the heat

Alessandro Mura, a Juno co-investigator from the National Institute for Astrophysics in Rome, said:

JIRAM detected an event of extreme infrared radiance — a massive hotspot — in Io’s southern hemisphere, so strong that it saturated our detector. However, we have evidence what we detected is actually a few closely spaced hotspots that emitted at the same time, suggestive of a subsurface vast magma chamber system. The data support that this is the most intense volcanic eruption ever recorded on Io.

The JIRAM science team estimates the as-yet-unnamed feature spans 40,000 square miles (100,000 square kilometers). The previous record holder was Io’s Loki Patera, a lava lake of about 7,700 square miles (20,000 square kilometers). The total power value of the new hotspot’s radiance measured well above 80 trillion watts.

Three images of a rusty brown and white moon. Purple arrows point to the same spot on each.
Images of Io captured in 2024 by the JunoCam imager aboard NASA’s Juno show significant and visible surface changes (indicated by the arrows) near the Jovian moon’s south pole. These changes occurred between the 66th and 68th perijove (the point during Juno’s orbit when it is closest to Jupiter). Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Jason Perry.

Volcanic activity on Io leaves a mark

The feature was also captured by the mission’s JunoCam visible light camera. The team compared JunoCam images from the two previous Io flybys with those the instrument collected on December 27. And while these most recent images are of lower resolution since Juno was farther away, the relative changes in surface coloring around the newly discovered hotspot are clear. Such changes in Io’s surface are known to be associated with hotspots and volcanic activity.

An eruption of this magnitude is likely to leave long-lived signatures. Other large eruptions on Io have created varied features, such as pyroclastic deposits (composed of rock fragments spewed out by a volcano), small lava flows that may be fed by fissures, and volcanic-plume deposits rich in sulfur and sulfur dioxide.

Juno will use an upcoming, more distant flyby of Io on March 3 to look at the hotspot again and search for changes in the landscape. Earth-based observations of this region of the moon may also be possible.

Bolton said:

While it is always great to witness events that rewrite the record books, this new hotspot can potentially do much more. The intriguing feature could improve our understanding of volcanism not only on Io but on other worlds as well.

Bottom line: On its most recent flyby, the Juno spacecraft spotted intense volcanic activity on Io, one of Jupiter’s moons. It was the most extreme volcanism ever seen on Io.

Via NASA

Read more: Io’s raging volcanoes are self-powered

Read more: Lava lakes on Io: Juno zooms in on Io’s volcanoes

The post Juno spots most extreme volcanic activity on Io to date first appeared on EarthSky.



from EarthSky https://ift.tt/OSvIwsc

Aucun commentaire:

Enregistrer un commentaire