Questions/Discussion about Juno's extended mission to study the Jovian moons.

[CassiniWeenie]

I'm a sucker for the Jovian moons. They're all so interesting and I've been patiently waiting for JUICE and the Europa Clipper missions, so to hear about Juno's extended mission has gotten me hyped. I haven't been able to find too much information about what kind of science the Juno team is expecting to get out of the moons. I know JunoCam will give us some truly spectacular closeups of these gorgeous moons and I'm incredibly excited to see those images, but I wanted to discuss some of the other instruments aboard the orbiter.



The Microwave Radiometer:

"The radiometer will measure the abundance of water and ammonia in the deep layers of the atmosphere up to 200 bar (20 MPa; 2,900 psi) pressure or 500–600 km (310–370 mi) deep. The combination of different wavelengths and the emission angle should make it possible to obtain a temperature profile at various levels of the atmosphere. The data collected will determine how deep the atmospheric circulation is."

I have two questions about this for anyone who is a bit more educated in this than I:

Given that it is designed for use in the Jovian atmosphere, will it be capable of penetrating the icy crusts of the moons or provide any other kinds of insights?

Also, it is mentioned that this instrument is only expected to function through 11 orbits, which I'm sure has passed. Anyone know if this instrument has yet to be fried from Jupiter's magnetosphere?



Jovian Infrared Auroral Mapper:

"The spectrometer mapper JIRAM, operating in the near infrared (between 2 and 5 μm), conducts surveys in the upper layers of the atmosphere to a depth of between 50 and 70 km (31 and 43 mi) where the pressure reaches 5 to 7 bar (500 to 700 kPa). JIRAM will provide images of the aurora in the wavelength of 3.4 μm in regions with abundant H3+ ions. By measuring the heat radiated by the atmosphere of Jupiter, JIRAM can determine how clouds with water are flowing beneath the surface. It can also detect methane, water vapor, ammonia and phosphine. "

It seems like this instrument might be able to help provide insight into the molecular makeup of the plumes of water being ejected from Europa. Though it is also mentioned that this instrument is only expected to function until the 8th orbit of Jupiter, so like before, does anyone know if this instrument is still functioning?



Magnometer:

"The magnetic field investigation has three goals: mapping of the magnetic field, determining the dynamics of Jupiter's interior, and determination of the three-dimensional structure of the polar magnetosphere. The magnetometer experiment consists of the Flux Gate Magnetometer (FGM), which will measure the strength and direction of the magnetic field lines, and the Advanced Stellar Compass (ASC), which will monitor the orientation of the magnetometer sensors."

Does anyone know if the magnometer will be sensitive enough to give us any insight into the weak magnetic fields of Ganymede and Europa?



Gravity Science instrument:

"The purpose of measuring gravity by radio waves is to establish a map of the distribution of mass inside Jupiter. The uneven distribution of mass in Jupiter induces small variations in gravity all along the orbit followed by the probe when it runs closer to the surface of the planet."

I'm curious if this will advance our understanding of the interior structures of the moons and maybe which areas of Europa's crust are thinnest.





The other instruments seem to focus on ions and high energy particles, so perhaps they will provide info on the tenuous atmospheres of the moons.



Ultimately, we have a packed schedule for the Jupiter system with Juno flybys through 2024 followed by JUICE and Europa Clipper arriving in 2029 and 2030 respectively. I'm so excited we don't have to wait 10 years to see the moons up close.

[Phil Stooke]

This presentation:

https://www.lpi.usra.edu/opag/meetings/opag2020fall/presentations/Bolton_6011.pdf

doesn't explicitly say everything is working, but it seems to imply most things are.  It does state that JIRAM is expected to provide data during the extended mission.

[CassiniWeenie]

This presentation:

https://www.lpi.usra.edu/opag/meetings/opag2020fall/presentations/Bolton_6011.pdf

doesn't explicitly say everything is working, but it seems to imply most things are.  It does state that JIRAM is expected to provide data during the extended mission.

Thanks, this is my first time seeing this presentation.

[vjkane]

The presentation states the types of observations that Juno can make.  To make all these observations, NASA would need to fund the extended mission at a higher level than it has proposed to do (NASA has a fixed budget for extended missions, and there's not enough money for any mission to do everything it could do).

At a Decadal Survey meeting, both the Juno PI and the NASA headquarters rep stated that the level of funding and hence the observations were still under discussion.

[Blackstar]

On Monday, June 7, at 1:35 p.m. EDT (10:35 a.m. PDT), NASA’s Juno spacecraft will come within 645 miles (1,038 kilometers) of the surface of Jupiter’s largest moon, Ganymede. The flyby will be the closest a spacecraft has come to the solar system’s largest natural satellite since NASA’s Galileo spacecraft made its penultimate close approach back on May 20, 2000.

[Star One]

The presentation states the types of observations that Juno can make.  To make all these observations, NASA would need to fund the extended mission at a higher level than it has proposed to do (NASA has a fixed budget for extended missions, and there's not enough money for any mission to do everything it could do).

At a Decadal Survey meeting, both the Juno PI and the NASA headquarters rep stated that the level of funding and hence the observations were still under discussion.

An extended mission would be the type of thing that a good budget allocation could be easy to justify I’d of thought with an existing proven spacecraft already at the location.

[Blackstar]

Is there a thread dedicated to Io and Io missions? I cannot find one. I guess this could go in a thread about potential Discovery class missions.


https://slate.com/technology/2023/09/io-jupiter-space-volcano-prometheus-mission-nasa.html

Io Is a Volcanic Hellscape of Fire and Ice
Let’s go explore it.
By Ryan Ogliore
Sept 27, 20233:53 PM

On March 9, 1979, Linda Morabito discovered a volcanic plume on Io, a moon of Jupiter, in one of the photos from Voyager 1. She wrote, “I could feel tears begin to roll down my face at the sight of a world more unexpected than imagination itself. … It was as if I had been gazing into destiny.”

In the 44 years since, Io has continued to amaze. Observations made by other spacecraft— Voyager 2, Galileo, Cassini, New Horizons, and currently, Juno—have revealed that Io is a dynamic hellscape of fire and ice. The surface temperature is a frigid 250 degrees below zero Fahrenheit, but Io’s volcanic eruptions produce extremely hot lavas that could be as high as 3,000 degrees (much hotter than we see today on Earth). Enormous lava lakes reaching more than 100 miles across dot Io’s surface. Fire fountains sporadically erupt and volcanic deposits change over a period of months. Amirani is the solar system’s longest active lava flow, stretching more than 200 miles. Io’s volcanic gases interact with Jupiter’s powerful magnetosphere to create the ominous-sounding “Io plasma torus,” bathing Io in radiation.

Towering mountains, in the shape of tilted blocks and more than twice as tall as Mount Everest, were likely formed by Io’s crust fracturing as Io continuously turns itself inside out. And just like we have ocean tides on Earth, Io has tides of rock: Its mountains rise and fall and rise again by 200 feet in 42 hours (the time it takes Io to orbit Jupiter). The tides are caused by the synchronous dance of the inner three Galilean moons (Io, Europa, and Ganymede) in a gravitational tug-of-war with Jupiter. The flexing and friction of rock rides creates the heat that fuels Io’s volcanism; the heating is so severe that an ocean of magma more than 30 miles thick likely lies beneath Io’s crust.

[Blackstar]

Io.

https://twitter.com/tedstryk/status/1714047324912017602/photo/1