NASA spacecraft observes lava lake and 'Steeple Mountain' on a volcanic moon in our solar system

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Discover the wonders of the universe, including close flybys of Io, one of Jupiter’s moons. Recent observations have unveiled a lava lake and a towering feature known as “Steeple Mountain” on Io’s unique surface.

NASA's Juno spacecraft, which began studying Jupiter and its moons in 2016, recently flew within about 930 miles (1,500 kilometers) of Io's surface. This close encounter allowed JunoCam to capture detailed images of Io's northern latitudes.

This mission marked the first time in over 20 years that a spacecraft came so close to Io. JunoCam's high-resolution images revealed active volcanic plumes, towering mountain peaks, and a serene lake of cooling lava on the mysterious moon.

Scott Bolton, Juno’s principal investigator at the Southwest Research Institute, shared that Io is filled with volcanoes, and they were able to observe some of them in action. Additionally, they gathered close-up images and data on Loki Patera, a 200-kilometer-long lava lake. The images reveal intricate details of islands within the lake surrounded by hot lava, giving the impression of a potentially magma-filled lake.

Moreover, the instruments captured a specular reflection of the lake, indicating parts of Io's surface are incredibly smooth, akin to glass. This smooth surface resembles the volcanically created obsidian glass found on Earth.

An animation based on Juno's data zooms in on a lava lake, called Loki Patera, on Io's surface.

CNN/NASA/JPL-Caltech/SwRI/MSSS. Image processing: Gerald Eichstädt/Thomas Thomopoulos (CC BY)

Bolton shared the latest discoveries on April 16 at the European Geophysical Union General Assembly in Vienna. The new information is helping scientists understand Io better, a moon that has fascinated researchers for a long time.

"It's the only other place besides Earth where we observe active magma volcanoes in our solar system," Bolton mentioned.

Exploring a strange world

The team used Juno's data to create animations that highlight some of the unique surface features of the alien world, including Loki Patera and Steeple Mountain.

Juno detected the mountain with the help of the sun shining on Io’s surface, which created dramatic shadows that revealed a very sharp peak.

NASA's Europa Clipper spacecraft will carry a special message when it launches in October 2024 and heads toward Jupiter's moon Europa. The moon shows strong evidence of an ocean under its icy crust, with more than twice the amount of water of all of Earth's oceans combined. A triangular metal plate, seen here, will honor that connection to Earth.

NASA's Europa Clipper spacecraft, scheduled to launch in October 2024 and journey towards Jupiter's moon Europa, will carry a unique message. The moon has compelling evidence of an ocean beneath its icy shell, containing over twice the amount of water found in all of Earth's oceans. To commemorate this link to our planet, a triangular metal plate will be on board the spacecraft. NASA/JPL-Caltech

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Bolton explained that scientific data was used to study shadows and determine distances. He mentioned that while it may not be exact, the area was named Steeple Mountain due to its steep edge, resembling Io's version of the Matterhorn.

Despite the magma's high temperature on Io, the moon's surface is estimated to be extremely cold, reaching minus 148 degrees Fahrenheit (minus 100 degrees Celsius), according to Bolton.

He mentioned that when a volcano erupts, the magma that comes out quickly freezes, possibly creating sulfur snow.

The Juno team focused on studying shadows to figure out the height and shape of a landform they named "Steeple Mountain."

NASA/JPL-Caltech/SwRI/MSSS

As an outdoors enthusiast, Bolton joked that Io’s Steeple Mountain should be one of the solar system’s skiing and snowboarding destinations.

Loki Patera is known for its extreme temperatures, with the lava lake being very hot and the island tops likely very cold. Bolton also mentioned the possibility of a cold crust surrounding the lake's edges.

Using Juno's Microwave Radiometer instrument, the mission team was able to produce maps of Io's surface, revealing its remarkable smoothness.

Io's topography lacks contours due to its high level of volcanic activity, constantly resurfacing the world with lava. A recent study by a separate research team, published in the journal Science on April 18, revealed that impact craters are often erased from Io's surface.

The team utilized the Atacama Large Millimeter/submillimeter Array of telescopes in Chile to study gases in Io's atmosphere. Their findings indicated an abundance of enriched sulfur and chlorine, suggesting that Io has been actively releasing these gases for most, if not all, of its 4 billion year history.

Revealing Io’s mysteries

Io, first discovered by Galileo Galilei in 1610, is just slightly larger than our moon, but it’s unlike anywhere else in the solar system.

The moon Io has a rocky surface with hundreds of volcanoes, reminiscent of the volcanic planet Mustafar from "Star Wars."

NASA scientists have witnessed Io's volcanoes erupting lava fountains reaching heights of dozens of miles, visible even through large telescopes on Earth.

The JunoCam instrument captured the first-ever image of Io's south polar region during Juno's 60th flyby of Jupiter on April 9.

The JunoCam instrument captured the first-ever image of Io's south polar region during Juno's 60th flyby of Jupiter on April 9.

Io, one of Jupiter's moons, got its name from a Greek myth involving a woman transformed into a cow during a disagreement between the gods Zeus and Hera. The name is quite suitable, as Io is constantly being pulled by the strong gravity of Jupiter and its other moons Europa and Ganymede.

Io experiences intense gravitational forces from its three neighboring worlds, causing its surface to bulge in and out by 330 feet (100 meters). This phenomenon is similar to the high and low tides we see on Earth, but on Io, it occurs on solid ground instead of in an ocean. Scientists often refer to Io as "Jupiter's tortured moon" due to the violent forces it constantly faces.

This image of Jupiter from NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) shows stunning details of the majestic planet in infrared light. In this image, brightness indicates high altitude. The numerous bright white ‘spots’ and ‘streaks’ are likely very high-altitude cloud tops of condensed convective storms. Auroras, appearing in red in this image, extend to higher altitudes above both the northern and southern poles of the planet. By contrast, dark ribbons north of the equatorial region have little cloud cover.In Webb’s images of Jupiter from July 2022, researchers recently discovered a narrow jet stream traveling 320 miles per hour (515 kilometers per hour) sitting over Jupiter’s equator above the main cloud decks.

This stunning image of Jupiter was captured by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera), showcasing the planet in infrared light. The brightness in the image indicates high altitude, with bright white ‘spots’ and ‘streaks’ likely representing very high-altitude cloud tops of condensed convective storms. Auroras, shown in red, can be seen extending to higher altitudes above both the northern and southern poles of Jupiter. In contrast, dark ribbons with little cloud cover can be observed north of the equatorial region.

In recent images taken by Webb in July 2022, researchers made an exciting discovery of a narrow jet stream moving at an incredible speed of 320 miles per hour (515 kilometers per hour) over Jupiter’s equator, located above the main cloud decks. This new finding adds to our understanding of the dynamic atmosphere of the gas giant.

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The intense forces from Jupiter, Europa, and Ganymede heat up Io's surface, causing its subsurface to resemble liquid rock. Scientists suggest that this liquid rock could be molten sulfur or silicate rock, and volcanic eruptions on the moon help release gravitational pressure.

Over the years, Io has been closely examined by various spacecraft such as the Pioneer, Voyager, and Galileo probes. Recently, Juno's findings have provided unprecedented insights into the factors driving the moon's volcanic eruptions.

Editor's P/S:

The article delves into the captivating world of Io, a moon of Jupiter known for its unique volcanic activity and intriguing surface features. Through the recent observations made by NASA's Juno spacecraft, scientists have gained valuable insights into Io's dynamic landscape. The discovery of a lava lake and a towering mountain, aptly named Steeple Mountain, highlights the moon's active volcanic processes. The article also sheds light on the extreme temperatures and geological processes that shape Io's surface, making it a fascinating subject of scientific study.

Furthermore, the article explores the historical significance of Io, first discovered by Galileo Galilei in the 17th century. It discusses the moon's role in Greek mythology and its relevance to our understanding of the solar system. The article also mentions the upcoming Europa Clipper mission, which will carry a special message commemorating the connection between Earth and Jupiter's moon Europa. By combining scientific discoveries with historical context, the article provides a comprehensive and engaging account of Io and its place in our solar system.