Tag: Juno

The uncertainty of science: Scientists today released their first measurements from Juno of the amount of water found in Jupiter’s atmosphere.

The Juno science team used data collected during Juno’s first eight science flybys of Jupiter to generate the findings. They initially concentrated on the equatorial region because the atmosphere there appears more well-mixed, even at depth, than in other regions. From its orbital perch, the radiometer was able to collect data from a far greater depth into Jupiter’s atmosphere than the Galileo probe – 93 miles (150 kilometers), where the pressure reaches about 480 psi (33 bar).

“We found the water in the equator to be greater than what the Galileo probe measured,” said Cheng Li, a Juno scientist at the University of California, Berkeley. “Because the equatorial region is very unique at Jupiter, we need to compare these results with how much water is in other regions.”

These results remain very preliminary, especially because they have not yet gathered data at higher latitudes. Regardless the amount so far detected, 0.25% of all molecules in Jupiter’s atmosphere. seems remarkably small, suggesting that Jupiter has relatively little hydrogen or oxygen in its atmosphere.

Citizen scientist Brian Swift has created a new movie from images taken by Juno during its December 25th close pass of Jupiter, the 24th such flyby of the spacecraft’s mission.

I have embedded the movie below. While it isn’t as spectacular as previous movies (see here, here, here, and especially here and here), as it appears that either Juno did not get quite as close, or Swift did not shape it to give that impression, it is still most breathtaking.

Cool image time! Citizen scientist Gerald Eichstädt has used images taken by Juno of Jupiter’s south polar storms to produce an animation that shows the evolution of those storms over a short time period.

The movie is more a computer model than an assemblage of images.

A fluid dynamical 2D model rotating with Jupiter’s System III rotation rate is started with a map of PJ19 (Juno’s 19th close approach) vorticity measurements of the south polar region between 75 and 90 degrees south (azimuthal, equidistant, planetocentric) as initial condition. The vorticity map is based on a sequence of PJ19 JunoCam images.

Relative vorticities are encoded in color, blue for cyclonic, orange for anticyclonic relative vorticity. The animated gif covers 48 hours, with one frame per real-time hour. Played with 25 fps, the result is a 90,000-fold time-lapsed animation.

I have embedded the animation below the fold. It is quite impressive.
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Click for full image.

New images from Juno have revealed the formation of a new Texas-sized cyclone joining the circle of storms around Jupiter’s south pole.

In the infrared Juno image to the right, the new storm is the small bright cyclone in the lower right.

[D]uring Juno’s 22nd science pass [on November 3], a new, smaller cyclone churned to life and joined the fray. “Data from Juno’s Jovian Infrared Auroral Mapper [JIRAM] instrument indicates we went from a pentagon of cyclones surrounding one at the center to a hexagonal arrangement,” said Alessandro Mura, a Juno co-investigator at the National Institute for Astrophysics in Rome. “This new addition is smaller in stature than its six more established cyclonic brothers: It’s about the size of Texas. Maybe JIRAM data from future flybys will show the cyclone growing to the same size as its neighbors.”

Probing the weather layer down to 30 to 45 miles (50 to 70 kilometers) below Jupiter’s cloud tops, JIRAM captures infrared light emerging from deep inside Jupiter. Its data indicate wind speeds of the new cyclone average 225 mph (362 kph) – comparable to the velocity found in its six more established polar colleagues.

Because of Juno’s orbit we do not get continuous views of the gas giant’s cloud-tops, so we can’t see the moment-by-moment evolution of these storms, which makes it impossible to obtain a full understanding of their formation or disappearance. Even then it will likely take centuries of observations to even begin to get a fuller understanding of the meteorology of Jupiter.

Click for full image.

Cool image time! The photo to the right, taken by Juno on November 3, was enhanced by citizen scientist Björn Jónsson to bring out the colors. It shows a band of repeating large storms, with tiny white thunderheads popping up within them.

The dark areas at the edges of the swirls are likely not an aspect of the clouds but shadows created because the white swirls sit higher than the surrounding gases.

Sadly the press release does not give us a scale. The image was taken from a distance of 3,200 miles. I suspect each cloud swirl would likely cover much of the Earth.

Click for full image.

Using raw Juno images, citizen scientist Gerald Eichstädt has created the processed and color enhanced image to the right, cropped to post here. From the Juno press release:

This view from NASA’s Juno spacecraft captures colorful, intricate patterns in a jet stream region of Jupiter’s northern hemisphere known as “Jet N3.”

Jupiter’s cloud tops do not form a simple, flat surface. Data from Juno helped scientists discover that the swirling bands in the atmosphere extend deep into the planet, to a depth of about 1,900 miles (3,000 kilometers). At center right, a patch of bright, high-altitude “pop-up” clouds rises above the surrounding atmosphere.

Some of the darker areas are darker mostly because they are lower and therefore in shadow.

The raw image was taken on May 29, 2019 when Juno was about 6,000 miles away. Unfortunately, they do not provide a scale, but I suspect that the image is probably close to the size of the entire Earth.

In order to avoid a twelve-hour plunge through Jupiter’s shadow that would have likely sucked all power from Juno’s solar powered systems and killed the spacecraft, mission engineers have successfully used its attitude thrusters to complete a 10.5 long engine burn.

Juno began the maneuver yesterday, on Sept. 30, at 7:46 p.m. EDT (4:46 p.m. PDT) and completed it early on Oct. 1. Using the spacecraft’s reaction-control thrusters, the propulsive maneuver lasted five times longer than any previous use of that system. It changed Juno’s orbital velocity by 126 mph (203 kph) and consumed about 160 pounds (73 kilograms) of fuel. Without this maneuver, Juno would have spent 12 hours in transit across Jupiter’s shadow – more than enough time to drain the spacecraft’s batteries. Without power, and with spacecraft temperatures plummeting, Juno would likely succumb to the cold and be unable to awaken upon exit.

“With the success of this burn, we are on track to jump the shadow on Nov. 3,” said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio.

This burn did not use the spacecraft’s main engine, which they fear has a problem that would produce a catastrophic failure if fired. Instead, they used Juno’s small attitude thrusters, which explains the length of the maneuver. In fact, this 10.5 hour burn might actually be the longest chemical engine burn in space ever. While ion engines routinely fire for this long or longer, as far as I can remember no chemical engine in space has ever fired even close to this length of time.

As he has done previously, citizen scientist Gerald Eichstädt has created a movie using Juno images of the spacecraft’s twenty-second fly-by of Jupiter.

I have embedded the movie below the fold. This fly-by included the images of Io’s shadow posted by other citizen scientists earlier. Because the movie shows this shadow in the context of the fly-by (near its lowest altitude), it illustrates why the shadow appears far larger than it is, relative to the entire planet.

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Click for full resolution image.

The image on the right, reduced to post here, was created by Citizen scientist Kevin Gill from recent Juno images taken of Jupiter, and shows in detail some of the many storms that fill Jupiter’s many bands of color.

We do not have a scale, but my guess is that these storms are probably about the size of the Earth, which means these storms are bigger than any hurricane you can imagine. If you click on the image to look at the full resolution photograph, you can see there are tiny white clouds clumped in the middle of the picture’s three biggest storms. Those clumps are probably also bigger than any single clouds you could find anywhere on Earth.

As I wrote in a post in April 2017 about a similar Juno image:

What should fill us with even more awe is that this only covers a very thin slice of the top of Jupiter’s deep atmosphere. The planet itself is about 89,000 miles in diameter, more than ten times larger than Earth. The depth of its atmosphere is not really known, but it must be deeper than several Earths, piled on top of each other. In that depth there must be many atmospheric layers, each thicker and denser than the one above, and each with its own weather systems and complexities.

It will take centuries of research, including the development of new engineering capable of accessing this place, to even begin to map out its meteorology. And this is only one gas giant, of what we now know must be millions and millions throughout the galaxy.

If we have the nerve and daring, the human race has the opportunity to go out there and never be bored. There will always be something unknown to discover.

All that still applies. We have only just begun our journey exploring the universe.

My headline above focuses on the real story here, that Juno has found that Jupiter’s solid core is more fuzzy and extended.

Unfortunately, the press release instead focuses on one theory, based on computer models, that might explain this discovery.

The research team ran thousands of computer simulations and found that a fast-growing Jupiter can have perturbed the orbits of nearby “planetary embryos,” protoplanets that were in the early stages of planet formation.

Liu said the calculations included estimates of the probability of collisions under different scenarios and distribution of impact angles. In all cases, Liu and colleagues found there was at least a 40% chance that Jupiter would swallow a planetary embryo within its first few million years. In addition, Jupiter mass-produced “strong gravitational focusing” that made head-on collisions more common than grazing ones.

Isella said the collision scenario became even more compelling after Liu ran 3D computer models that showed how a collision would affect Jupiter’s core. “Because it’s dense, and it comes in with a lot of energy, the impactor would be like a bullet that goes through the atmosphere and hits the core head-on,” Isella said. “Before impact, you have a very dense core, surrounded by atmosphere. The head-on impact spreads things out, diluting the core.”

This theory is all well and good, but we mustn’t take it too seriously. It relies entirely on computer models, and carries with it enormous assumptions about the early solar system that are as yet unproven.

That Jupiter’s core however is fuzzy and extended however is quite fascinating, highlighting once again how little we know about the universe.

Cool image time! Using images from Juno, a citizen scientist going under the nom de plume YobiRoby has created the height map image to the right, showing three-dimensionality of the cloud surface of Jupiter.

Though they provide no details to go with this image, it appears it is centered on Jupiter’s Great Red Spot, the larger of the two big storms that are visible. While the smaller storm appears raised like a mound above the surrounding cloudtops, the Great Red Spot instead appears to be a mound that is depressed below the cloudtops.

The image on the right, cropped to post here, was taken by Juno on February 12, 2019 as the spacecraft made its 17th close approach of Jupiter. The Juno science team today has highlighted this version, processed by citizen scientists Gerald Eichstädt and Seán Doran to enhance the details therein. They note how the white clouds can clear be seen sitting above the colored clouds below.

I cropped it to show the center of the storm. The full image is equally spectacular, as it shows the full storm. Unfortunately, there is no scale, but I suspect you could probably fit the entire Earth several times across the diameter of the storm.

Using several instruments, the Juno science team has successfully photographed an active volcano plume in Io’s polar regions. Two instruments measured the plume’s heat and radiation. Juno’s cameras meanwhile took the color image on the right. The bright spot on Io’s night side matches the location of the heat and radiation signatures from the other instruments.

JunoCam acquired the first images on Dec. 21 at 12:00, 12:15 and 12:20 coordinated universal time (UTC) before Io entered Jupiter’s shadow. The Images show the moon half-illuminated with a bright spot seen just beyond the terminator, the day-night boundary. “The ground is already in shadow, but the height of the plume allows it to reflect sunlight, much like the way mountaintops or clouds on the Earth continue to be lit after the sun has set,” explained Candice Hansen-Koharcheck, the JunoCam lead from the Planetary Science Institute.

This image is not the first time a spacecraft has caught an active volcanic plume on Io. In fact, practically the very first good images of Io during the Voyager 1 fly-by did this, confirming then that volcanoes are active on the Jupiter moon.

What this image further confirms however is how active Io really is. Volcanoes erupt there so continuously that it apparently isn’t that hard to catch one as it happens.

Cool movie time! Citizen scientist Gerald Eichstädt has created a time lapse movie using the images taken by Juno during its sixteenth close fly-by of Jupiter on October 29, 2018.

The movie is embedded below the fold. Quite spectacular. The colors are enhanced to bring out the details, and begins looking down at Jupiter’s north hemisphere at night.
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Cool image time! The photograph on the right, reduced to post here, was created by citizen scientists Gerald Eichstädt and Seán Doran from the raw images taken by Juno during the spacecraft’s 16th close fly-by of Jupiter on October 29, 2018. If you click on it you can see the full resolution image.

At the time, Juno was about 4,400 miles (7,000 kilometers) from the planet’s cloud tops, at a latitude of approximately 40 degrees north.

What attracts me to this image is its dimensionality. First, it looks at Jupiter from an oblique angle. Second, the shadows of the upper clouds can clearly be seen being cast on the lower clouds. Third, if you look at the full resolution image you can even see this effect in the middle of the big white storm in the image’s top left.

What frustrates me about this image is that Juno is not in an orbit around Jupiter allowing it to make extended movies of the evolution of these cloud features. Gaining even a limited understanding the meteorology of this gas giant will simply not be possible until we can do this, and that will require many satellites orbiting the planet.

Cool image time! The image on the right, cropped to post here, shows the white center of one of the smaller giant storms on Jupiter, taken by Juno. The image was processed by citizen scientists Gerald Eichstädt and Seán Doran. If you click on the image you can see the entire picture, which has a host of spectacular details surrounding the white spot.

Unfortunately, they do not provide a scale. Based on past experience, I would guess that this tiny storm probably exceeds the size of the Earth. What makes the image so impressive however are the white cloudtops visible as they swirl around the storm’s center. Sunlight shadows clearly shows that these thunderheads rise above rest of the storm.

The full image shows even more fascinating details. It is worthwhile studying, though one can certainly get lost in that vast and turbulent Jupiter atmosphere.

Cool image time. Mathematician and software programmer Gerald Eichstädt has released another movie using images from Juno’s thirteenth close fly-by of Jupiter.

I have embedded the movie below the fold. As he notes,

The movie covers two hours of this flyby in 125-fold time lapse, the time from 2018-05-24T04:41:00.000 to 2018-05-24T06:41:00.000. It is based on 27 of the JunoCam images taken during the flyby, and on spacecraft trajectory data provided via SPICE kernel files.

The view begins by looking down at the northern hemisphere, and gets to within 2,200 miles of the giant planet’s cloud tops.

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Several Juno images that have been cleverly processed by citizen scientists are being highlighted at a Jupiter conference being held in London this week.

JunoCam images presented at the meeting by citizen scientists Gerald Eichstädt and Seán Doran include an animation showing the evolution of swirling features in the giant planet’s atmosphere and a composite image of Jupiter’s cloud tops.

Gerald Eichstädt, a mathematician working as a software professional, has taken two images from JunoCam and reprojected them to the same vantage point to enable a direct comparison between the images and show the subtle motions within the atmosphere. By modelling the movement of individual pixels in the images, he has created an animation that extrapolates the swirling evolution of the vortices in the atmosphere.

Eichstädt explains: “This animation represents a ‘feasibility test’. Building on this initial work, we can add in more variables that will give us a more detailed description and physical understanding of Jupiter’s atmosphere.”

Seán Doran, in collaboration with Eichstädt, has created a new composite image of Jupiter as seen by Juno as it swung away from Jupiter’s south pole on 1st April 2018. Because Jupiter was larger than JunoCam’s field of view when the main portion of the image was taken, Eichstädt rendered four other images to the same viewing geometry to reconstruct a mosaic of the whole planet. Doran then processed the composite image to balance and blend the overlapping components, sharpen the contrast, and fill gaps.

I have myself highlighted images by both previously at Behind the Black, here and here and here and here. This press release nicely places both in the limelight at last.

The Juno science team has released an animation that shows, in infrared and in three dimensions, the storms of Jupiter’s north pole.

The link has three videos. One shows the gas giant’s surprisingly irregular magnetic field, as found by Juno. The first and third show a low and a high fly-over of the north pole, in infrared. I have embedded both fly-overs below the fold. First watch the high fly-over, which is the first video. This will make the low fly-over more understandable as it flies over the eight smaller storms that encircle the pole’s central vortex.
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Cool image time! Yesterday I posted a short gif created by citizen scientist Gerald Eichstädt, using twelve Juno images, that showed some cloud changes over time. Today, I discovered that Eichstädt has created an even more spectacular movie, which I have embedded below the fold, based on images taken during Juno’s tenth close fly-by.

This movie shows the short-term dynamics Jupiter’s southern storms derived from raw JunoCam images of Juno’s Perijove-10 flyby on Dec 16, 2017.

You might also notice the effect of changing solar illumination on the appearance of the haze bands. JunoCam usually takes a time-lapse sequence of images during each perijove showing Jupiter’s polar regions. These images are taken from different perspectives along Juno’s trajectory. But it’s possible to reproject the JunoCam images to a common perspective. Displaying such a sequence rapidly reveals cloud motion in Jupiter’s storm systems.

This movie applies this technique. At the same time, it is changing the simulated perspective along Juno’s trajectory. The same short sequence of images is displayed in a loop, but due to the changing way of reprojecting the raw images, the shown surface area is changing more or less continuously.

Eichstädt warns that the blinking nature of the film might make it unsuitable for those with epilepsy. If this is not an issue for you, you should then definitely take a look.
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