These interesting satellites are known as the Galilean Moons after Galileo Galileo, who first noticed them in 1610. The three ice neighbors Europa, Ganymede, and Callisto contain oceans inside them that may host life, and this has piqued scientists’ interest in them for many years. However, Io has also recently become a focus of attention because of the volcanic activity on its surface and lava plumes that extend 300 to 500 km (186 to 310 mi) into space. Since its launch in 2016, NASA’s Juno spacecraft has been orbiting Jupiter, the main scientific target, and has delivered breathtaking photographs of Io.
The most recent, which was captured by the main camera of the Juno probe (JunoCam) on July 31, 2023, at 05:03 AM UTC (01:03 AM EDT; July 30, 10:03 PM PDT), revealed Prometheus ejecting lava. The Prometheus Patera, a 28 km (17 mi) wide volcanic pit, is where this active volcano is situated on the hemisphere that faces away from Jupiter. Prometheus has earned the moniker “Old Faithful of Io” in the astrogeological world due to its reputation for frequent outbursts. The NASA Planetary Science Division tweeted a photograph of the eruption that has been processed (see below).
The picture was captured by Juno during its 53rd orbit around Jupiter (perijove 53), at which time the spacecraft once more circled the gas giant from pole to pole. The Junocam science team captured numerous photographs during this most recent flight to search for lightning storms in Jupiter’s atmosphere, cyclones in the polar region, filamentary clouds, and jets. During perijove 53, the probe also made its closest approach to Io, passing within 22,000 kilometers (13,700 miles) of the moon’s surface. The probe has been approaching the volcanic satellite closer and closer over the course of the last few flybys.
On May 16, the Juno probe made a prior flyby of Io, coming near 35,600 kilometers (22,100 miles) on the surface. The Volund region, home to the two active volcanoes Volund A and Volund B, was photographed by JunoCam on this occasion and revealed signs of eruptions. What seemed to be “smudges” on the landscape, which scientists regard as a “smoking gun” for outgassing related to volcanic plumes, served as a sign of this.
The mission controllers made the decision to explore Io’s surface and gain more information on its numerous volcanic zones during its most recent and closest approach. In addition to the images captured by the JunoCam, the Italian Space Agency’s (ASI) Jovian InfraRed Auroral Mapper (JIRAM) and other science tools gathered a significant amount of data. This most recent data set is anticipated to shed further light on the hundreds of volcanoes that are constantly spewing molten lava and sulfurous gases all over the surface and tenuous atmosphere of the moon.
Scientists are nonetheless eager to see fresh images of eruptions on the moon, despite the fact that Io’s volcanoes have been photographed repeatedly over the past three decades by three NASA spacecraft (Galileo, New Horizons, and Juno). The primary mission of the Juno probe was initially intended to span four years (until 2020), however it has subsequently been extended twice: once to July 30th, 2021, and once more to September 2025. In conjunction with Perijove 57 and 58, Juno is anticipated to make two additional close approaches to Io. Please send more optical and thermal photographs of Io’s erratic, exploding surface.
The JunoCam website and various versions of the data product both have the raw photos that may be downloaded and processed. Researchers from the Southwest Research Institute (SwRI) in San Antonio, Texas, are in charge of the JunoCam.
