Jupiter Is Now The Planet With The Most Known Moons 

Astronomers have announced that Jupiter is now the planet in our Solar System with the most moons. 

Saturn and Jupiter have been in a battle for the most moons for quite some time now. In 2019, Saturn took the title from Jupiter, however, astronomers have now counted 12 previously unknown moons in orbit around Jupiter; the Solar System’s largest planet.

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The current known total of Jupiter’s moons is now 92, while Saturn currently has 83 known moons. 

According to Science Alert, the observations were led by Scott Sheppard, an astronomer for Carnegie Institution for Science. The new findings have been published by the International Astronomical Union’s Minor Planet Center, which is known for keeping records of all the small bodies newly discovered in the Solar System. 

“Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects,” Sheppard said back in 2018 when his team initially discovered a dozen new moons orbiting the planet. 

These planet’s moons are quite small and dim, making them difficult to see, which is why it makes sense that we’re continuously discovering new ones. 

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According to Sky & Telescope, “nine of the newly discovered moons are quite distant from Jupiter, orbiting in a retrograde motion, the opposite direction to Jupiter’s rotation.

This is not weird; most of Jupiter’s moons are retrograde. This motion means they were probably passing rocks that were snared by Jupiter’s gravity and remained in orbit.”

The additional three moons are closer to Jupiter, and orbiting in the same direction as the planet. Jupiter itself is also extremely bright, so seeing the newer moons has been a challenge due to how dim they are. 

The newly discovered moons were initially spotted in 2021 and 2022, however, it takes time to confirm that these small planetary objects are actually moons. Follow-up observations need to be done both one month and one year after the initial sightings, which is also helpful for tracking the orbits of them. 

According to these reports, it’s very possible that there are even more moons surrounding both Jupiter and Saturn that are yet to be discovered. For now Jupiter holds the lead for Solar System planets with the moons, and only time, and scientific discovery, will tell whether or not it remains in that position.

Jupiters Moon

Loki, A Massive Volcano On Jupiter’s Moon Io, Could Erupt This Month

Jupiter’s moon Io is potentially making scientific history this week, more specifically a volcano named Loki on the moon’s surface. Loki is set to potentially erupt at some point within the final weeks of September and if that prediction is correct, scientists may have found one of the most predictable volcanoes within our solar system. 

Jupiter contains a total of four moons in its orbit. Callisto, Ganymede, and Europa all contain the same level of subsurface oceans, Io is the only one without any. Instead, it’s equipped with over 400 active volcanoes, making it the most volcanic-ally populated body in our solar system. Loki is the biggest volcano on the moon, and in general is the largest and most active volcano in the entire solar system, including any volcano found here on Earth. In 1979 scientists learned about the continuous and semi-predictable nature of Loki, and as the years went on, they began to notice more and more of a pattern. In 2002, Julie Rathbun, who is now a Senior Scientist with the Planetary Science Institute, was one of the first writers in a report that stated the volcano’s eruptions were regular, and is also the one who is predicting it’s eruption this month. 

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Jupiter and Io

Loki is so large that many telescopes can see it on Earth when Jupiter is visible, and because of this Rathbun and fellow author J.R. Spencer, concluded that between the years of 1988 and 2000 Loki erupted every 540 days exactly. After that it was a “more or less 500 days” type of situation, and then in 2013 it became even more periodical and erupted every 475 days for 160 days of constant eruption. 

In a press release from the Planetary Science Institute, Rathbun said, “If this behavior remains the same, Loki should erupt in September 2019, around the same time as the EPSC-DPS meeting in Geneva. We correctly predicted that the last eruption would occur in May of 2018.” 

Scientists are eagerly awaiting for Loki’s September eruption, because if Rathbun’s theory proves to be correct, it’ll be a huge scientific milestone in terms of volcanic predictability. Even the volcanoes on Earth that erupt in a “predictable” fashion have never been as consistent at Loki, at least in terms of when scientists have predicted eruptions for other volcanoes and how often/correct they were. 

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Io and its many volcanoes

“Volcanoes are so difficult to predict because they are so complicated.  Many things influence volcanic eruptions, including the rate of magma supply, the composition of the magma – particularly the presence of bubbles in the magma, the type of rock the volcano sits in, the fracture state of the rock, and many other issues,” Rathbun said.

Loki’s massive size is what leads scientists to their predictions, and makes the job of predicting when a volcano that’s over 300 million miles away will erupt, much easier. Rathbun discussed in her paper that because of its size basic physics principles can be used to predict its eruption patterns, and smaller factors within the volcano, that would normally hinder the prediction results in smaller volcanoes, have little to no impact on the data. “However, you have to be careful because Loki is named after a trickster god and the volcano has not been known to behave itself.  In the early 2000’s, once the 540 day pattern was detected, Loki’s behavior changed and did not exhibit periodic behavior again until about 2013,” Rathbun said

The volcano is about 126 miles long, and it’s “predictable” nature is supposedly due to the crust of the volcano itself overturning with every eruption. Every time the volcano erupts, a new layer of magma coats the entire formation, and hardens into a new solid crust. Eventually, this crust becomes unstable, which then leads to another eruption and so on and so on. Rathbun and scientists alongside her studying Loki, believe the volcano is becoming less predictable potentially due to a change in porosity of the lava. Which basically means there’s more space in between the particles of the lava, making the consistency different, and therefore the hardened crusts on Loki will continue to be less stable than the layers prior to it. Regardless, the focus is on the remaining days of September and if Rathbun and her team will make prediction history, we just need to wait for Loki now.