Tag: Jupiter

Looking into one of Jupiter’s smaller cyclones

9:47 am

A northern cyclone on Jupiter
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Cool image time! The photo to the right, cropped and reduced to post here, was taken by the Juno probe orbiting Jupiter and enhanced first by citizen scientist Kenneth Gill and then further enhanced by citizen scientist Navaneeth Krishnan.

Sadly all the link tells us about this storm is that it is in the northern hemisphere. Based upon the colors, my guess is that it located at the high latitude where Jupiter’s bands transition to the chaotic region of storms at the poles, as seen in this earlier wide image of the gas giant’s south pole.

No scale is provided, but an earlier image of other northern hemisphere storms suggests this storm would probably cover the state of Arizona.

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Europa Clipper to fly on commercial rocket, not SLS

11:30 pm

NASA managers have now decided unequivocally to not use SLS to launch Europa Clipper, and will instead choose a commercial rocket in about a year.

During a Feb. 10 presentation at a meeting of NASA’s Outer Planets Assessment Group (OPAG), leaders of the Europa Clipper project said the agency recently decided to consider only commercial launch vehicles for the mission, and no longer support a launch of the spacecraft on the SLS.

“We now have clarity on the launch vehicle path and launch date,” Robert Pappalardo, project scientist for Europa Clipper at the Jet Propulsion Laboratory, said. That clarity came in the form of a Jan. 25 memo from NASA’s Planetary Missions Program Office to “immediately cease efforts to maintain SLS compatibility” and move forward with a commercial launch vehicle, or CLV, he said.

Though this decision was expected following the approval of the most recent congressional budget for NASA, which contained language allowing NASA to abandon SLS if it thought it wise, this decision continues the string of recent stories that all point toward the eventually abandonment of SLS itself.

At the moment the rocket most likely to win the contract is the Falcon Heavy.

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Jupiter’s southern jet streams

9:21 am

Jupiter's southern jet streams
Click for full image.

Cool image time! The photo to the right, rotated and reduced slightly to post here, shows the southern jet streams in Jupiter’s atmosphere. From the press release:

The storm known as the Great Red Spot is also visible on the horizon, nearly rotated out of view as Juno sped away from Jupiter at about 30 miles per second (48 kilometers per second), which is more than 100,000 mph (160,900 kilometers per hour).

Citizen scientist Tanya Oleksuik created this color-enhanced image using data from the JunoCam camera. The original image was taken on Dec. 30, 2020 as the Juno spacecraft performed its 31st close flyby of Jupiter. At the time, the spacecraft was about 31,000 miles (about 50,000 kilometers) from the planet’s cloud tops, at a latitude of about 50 degrees South.

According to data obtained by Juno, these bands of storms extend about 1,800 miles into Jupiter’s interior, much deeper than expected.

The Great Red Spot is at about 22 degrees south latitude, so this tells us that this picture covers Jupiter’s southern hemisphere from about the equator down to about 80 degrees.

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NASA extends mission of Juno and InSight probes

8:08 am

NASA has decided to extend the missions of Juno and InSight probes, giving both several more years to gather data.

InSight main goal for the two-year extension will be to gather more seismic data of Mars. They will also continue their efforts to get the heat sensor into the ground, but that will have a lower priority.

Juno will be able to slowly adjust its orbit to better study Jupiter’s north polar regions, thus developing a more complete first rough map of the gas giant’s internal structure and atmosphere. The changing orbit will also allow the first close fly-bys of some of Jupiter’s moons, the first in more than twenty years.

The moon flybys could begin in mid-2021 with an encounter with Ganymede, Jupiter’s largest moon, at a distance of roughly 600 miles (1,000 kilometers), Bolton said last year.

After a series of distant passes, Juno will swoop just 200 miles (320 kilometers) above Europa in late 2022 for a high-speed flyby. Only NASA’s Galileo spacecraft, which ended its mission in 2003, has come closer to Europa.

There are two encounters with Jupiter’s volcanic moon Io planned in 2024 at distances of about 900 miles (1,500 kilometers), according to the flight plan presented by Bolton last year. Juno will be able to look for changes on the surfaces of Jupiter’s moons since they were last seen up close by NASA’s Voyager and Galileo probes.

While it will take images, Juno’s camera is not particularly high resolution. The main effort will be to use its instruments to study the surface make-up of the moons.

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Congress frees Europa Clipper from SLS

9:10 am

It appears that Congress has at last removed its requirement that the unmanned probe Europa Clipper must be launched on the continually delayed and very expensive SLS rocket.

Almost unnoticed, tucked into the 2021 fiscal NASA funding section of the recently passed omnibus spending bill, is a provision that would seem to liberate the upcoming Europa Clipper mission from the Space Launch System (SLS).

According to Space News, the mandate that the Europa Clipper mission be launched on an SLS remains in place only if the behind-schedule and overpriced heavy lift rocket is available and if concerns about hardware compatibility between the probe and the launcher are resolved. Otherwise, NASA is free to search for commercial alternatives to get the Europa Clipper to Jupiter’s ice-shrouded moon.

Not only will this secure Europa Clipper’s launch schedule, which had deadlines imposed by orbital mechanics that SLS was not going to meet, the more than $1 billion in savings by using a SpaceX Falcon Heavy will allow the probe to do more while giving NASA more money for other planetary missions.

This is excellent news. It signals that Congress’s long love affair with SLS because of the ample pork it sends to many districts might finally be waning. If so, there is a good chance it will finally be killed, freeing up its bloated budget.

Sadly, in a sane world some of those savings would be used to reduce the overall federal deficit even as some was also used to expand NASA’s space effort. We are not in a sane world, however, so expect no reduction in the federal budget, at all.

Still, this is a move by Congress towards some fiscal responsibility that will make NASA’s efforts more efficient. For that small improvement we should be grateful.

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The conjunction of Jupiter and Saturn, as seen from the Moon

9:21 am

Jupiter and Saturn as seen by LRO
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With Jupiter and Saturn closer to each other in the sky than they have been in about 800 years, the science team for Lunar Reconnaissance Orbiter (LRO) decided to aim that lunar orbiter at the two gas giants to get a picture.

The photo to the right, cropped and expanded to post here, was also enhanced by the science team to brighten Saturn so that it would match Jupiter. As they note at the link,

[LRO] captured this view just a few hours after the point of closest separation (0.1°) between the two giant planets. With the sharp focus of the NAC [camera], you can see that the two planets are actually separated by about 10 Jupiter diameters

Both planets however look fuzzy in the image, probably because the camera was not designed to obtain sharp images from this distance. Nonetheless, this is a very cool photo.

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Trump administration asks Senate to remove SLS requirement for Europa Clipper

8:55 am

The Trump administration has requested the Senate to change the language in its NASA spending bill to remove its requirement that Europa Clipper be launched on SLS.

NASA wants the option to launch the Europa probe using commercial rockets, such as SpaceX’s Falcon Heavy. It also says that there are technical reasons that make using SLS problematic, and worse, the agency simply does not have enough SLS rockets to fly its planned (but unfunded) manned Artemis missions and also launch Europa Clipper.

The House has already removed that requirement in its version of the bill. The Senate has not, probably because the chairman of the Senate Appropriations Committee, Richard Shelby (R-Alabama), is a big fan of SLS (much of it built in his state), and has acted for years to pump money into that project.

If the requirement is not removed, Europa Clipper’s launch will likely be delayed by several years, and cost $1.5 billion more.

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Orbit of pristine comet in outer solar system is shifting inward

10:43 am

The orbit of a pristine comet that until now has kept it in the outer solar system, where it never got warm enough shed any material, is now shifting inward to join what is dubbed the Jupiter-family of comets, whose orbits are generally within that of Jupiter.

Although it has likely lost some supervolatile ices such as carbon dioxide ice (also known as dry ice) in the outer solar system beyond Jupiter, it is unlikely to have ever been in the inner solar system (where Earth, the other rocky planets, and [Jupiter-family comets] orbit), which is warm enough for water ice to sublime (‘evaporate’ from solid to gas),” Steckloff said. “This means that [Comet 2019] LD2 is a pristine comet, and presents a unique opportunity to observe how pristine [Jupiter-family comets] behave as their water ice begins to sublime for the first time and drive comet activity. Moreover, this transition is likely to finish in only 40 years from now, which is a blink of an eye for astronomy. This means that people alive today will be able to follow this object all the way through its transition into the [Jupiter-family] population.”

In 2019, when 2019 L2 was first identified, it was thought to be an asteroid that had suddenly become active, like a comet. Astronomers soon realized this was a mistake, that it was a comet whose orbit was being changed by its interaction with Jupiter.

The new data refines this conclusion, and confirms that observations of 2019 L2 will provide a lot of information about the make-up of the early solar system. More important, the comet’s orbit will allow for many observations, over a long period of time, unlike most comets that zip around the Sun in a year or so and then are gone.

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Jupiter’s stormy southern polar regions

2:46 pm

Jupiter's polar regions
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Cool image time! The photo to the right shows the southern polar regions of Jupiter. The image, taken by Juno during its 29th close-fly of Jupiter, was enhanced by a citizen scientist who only goes by the nickname Flury-21. This in fact was this person’s first try at enhancing a Juno image. He or she did a nice job, but provided no additional information other than saying that he “used lightroom to enhance the image and mostly used the dehaze effect.”

Works nicely nonetheless to illustrate how the bands that dominate Jupiter’s equatorial and mid-latitude regions disappear at the pole. Instead, the pole is a region of chaotic independent hurricanes, many bigger than North America. Other images from Juno suggest that they change relatively quickly. For example, compare this image of the south pole with an earlier one taken during the 28th fly-by. While we might not be looking at the same hemisphere, it is hard to believe there is no overlap between both images. Yet I can find no corresponding features.

The two images of course were taken months apart, and thus it is not surprising the storms have changed completely. However, I also suspect, given their size, that even over this time span some storms have survived, but changed so much it is hard to link them together. The only way to do this would be to have an orbiter close enough all the time to make movies. Unfortunately, Juno cannot do this, and I don’t expect any orbiter like this to reach Jupiter for many decades.

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Analyzing the evolving “small” storms in Jupiter’s atmosphere

12:09 pm

The vortices in Jupiter's polar regions
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The cool image to the right is another Juno photo of Jupiter enhanced by citizen scientist Gerald Eichstädt. This time Eichstädt also did some analysis of the motions and interactions of many vortices found in the northern polar regions of Jupiter. The image to the right has been cropped and reduced to post here, with the state of Arizona, about 400 by 300 miles in size, added for scale. There is more annotation in the full image.

As Eichstädt writes:

Large vortices in an atmosphere layer of a rotating planet can be roughly split into two classes, cyclonic and anticyclonic vortices.

Based on this rough classification, two interacting vortices can either be of the same or of opposite sign. Tightly interacting vortices of opposite sign tend to mutually propel each other, hence the whole pair, if they are of similar strength and size.

Tightly interacting vortex pairs of the same sign tend to merge. More distant like-signed vortex pairs may essentially repel each other. Interacting vortices tend to create filaments, some of which may split into fragments and further collapse into streets of small eddies.

He also notes that in future orbits Juno will provide closer views of this stormy region, as with the orbit the closest point shifts northward.

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Europa Clipper to be delayed because of SLS bottleneck

10:06 am

Because Boeing will be unable to provide an SLS rocket in time for the planned 2024 launch of Europa Clipper, once the probe is completed NASA will be forced to put it in storage.

The problem is that Congress has mandated that the Jupiter probe be launched on SLS, but has only funded the first two Artemis launches to the Moon. Boeing will also need at least three years to build it, meaning that even if the money from Congress appeared today, it would likely not be ready for its ’24 launch date.

In terms of rocket science, right now, Europa Clipper can launch on a commercial vehicle, like SpaceX’s Falcon Heavy or United Launch Alliance’s Delta-IV Heavy rocket, although the mission would then need a longer cruise time to reach its destination.

But in terms of the law, NASA’s hands are tied.

“Because of that, we’re planning to build the Europa Clipper and then put it into storage, because we’re not going to have an SLS rocket available until 2025,” Bridenstine said. “That’s the current plan. I don’t think that’s the right plan, but we’re going to follow the law.”

Though the common sense thing for Congress to do would be to release NASA from this mandate and allow the agency to pick the launch rocket, do not expect that to happen. Congress wants SLS because of all the pork it produces. They will not allow NASA to reduce its reliance on SLS one iota, if they can. Unless pressured publicly (which I think is NASA’s goal with this announcement), Congress will let Europa Clipper sit in a warehouse for years, at a cost of between $36 to $60 million per year, waiting for SLS.

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The face on Jupiter

9:56 am

The face on Jupiter!

Citizen scientist Gerald Eichstädt has created a two-image blink animation from Juno images of Jupiter that shows the changes in the two oppositely rotating storm vortices, shown on the right. As he notes.

Two vortices or eddies, one cyclonic, the other one anticyclonic, can propell themselves mutually and slowly within the overall context they are embedded in.

…The rotation of the two vortices is perceptible in the image sequence taken within nine minutes. The cyclonic eddy is located at the left, the anticyclonic one at the right. The motion of the vortex pair, however, is too slow to be resolved. But the morphology of the cloud tops points towards a relative upward motion in this rendition.

That the two storms also invoke face I am sure also had something to do with his decision to showcase this data. Unlike the face on Mars, this face is real, though relatively temporary. It will eventually break apart as Jupiter’s storms evolve.

The animation can be seen at the link.

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Juno science team proposes fly-bys of Jupiter’s moons

8:30 am

The Juno science team has proposed doing fly-bys of three of Jupiter’s moons, should NASA extend the mission beyond ’21.

Juno’s five-year primary mission phase ends in July 2021, and mission managers have proposed an extension that would continue operations until September 2025. The spacecraft’s additional orbits around Jupiter will bring Juno closer to the planet’s moons, allowing for a more diversified set of scientific targets.

…The moon flybys would begin in mid-2021 with an encounter with Ganymede, Jupiter’s largest moon, at a distance of roughly 600 miles (1,000 kilometers), according to Bolton.

After a series of distant passes, Juno would swoop just 200 miles (320 kilometers) above Europa in late 2022 for a high-speed flyby. Only NASA’s Galileo spacecraft, which ended its mission in 2003, has come closer to Europa.

There are two encounters with Jupiter’s volcanic moon Io planned in 2024 at distances of about 900 miles (1,500 kilometers), according to the flight plan presented by Bolton last month.

The extended mission would also allow scientists to get a better look at Jupiter’s north pole.

NASA will decide on the extension by the end of the year. From a cost and scientific perspective, it makes perfect sense to extend this mission for as long as possible. Compared to launching a new mission, extending an active one is far cheaper. It is also already in place.

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Flying over Jupiter

11:02 am

Cool movie time! Using images produced by Juno in orbit around Jupiter, citizen scientist Kevin Gill has produced a very nice movie of the spacecraft’s 27th fly-by on June 2, 2020.

During the closest approach of this pass, the Juno spacecraft came within approximately 2,100 miles (3,400 kilometers) of Jupiter’s cloud tops. At that point, Jupiter’s powerful gravity accelerated the spacecraft to tremendous speed — about 130,000 mph (209,000 kilometers per hour) relative to the planet.

I have embedded the movie below the fold. The choice of a piece of music by Vangellis might seem hokey, but I think in this case it works very nicely. I also was impressed with the addition of some 3D depth near the movie’s beginning.
» Read more

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Hubble snaps new hi-res photo of Jupiter

10:01 am

Jupiter, as seen by Hubble in 2020
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Astronomers have used the Hubble Space Telescope to take a new global image of Jupiter, aimed to provide an global census of the gas giant’s storm systems.

This latest image of Jupiter, taken by NASA’s Hubble Space Telescope on August 25, 2020, was captured when the planet was 406 million miles from Earth. Hubble’s sharp view is giving researchers an updated weather report on the monster planet’s turbulent atmosphere, including a remarkable new storm brewing, and a cousin of the famous Great Red Spot region gearing up to change color – again.

The moon seen to the left is Europa. Hubble takes annual images of the planets outward from Earth in order to provide scientists this global view.

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Juno’s 28th fly-by of Jupiter

10:20 am

Cool movie time! Below is a short movie created by citizen scientist Gerald Eichstädt from images taken by Juno as it swung past Jupiter on its 28th close pass since arriving in orbit in 2016.

In natural colors, Jupiter looks pretty pale. Therefore, the still images are approximately illumination-adusted, i.e. almost flattened, and consecutively gamma-stretched to the 4th power of radiometric values, in order to enhance contrast and color.

Like for all its previous flybys, Juno approached Jupiter roughly from north, and left Jupiter looking towards the soutern hemisphere. Closest approach to Jupiter was 3,500 km above the nominal IAU 1-bar level, and near 25.3 degrees north (planetocentric), according to long-term planning of November 2017.

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Giant impact covered almost half of Gandymede’s surface

9:31 am

Artist's illustration of Ganydmede
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The uncertainty of science: Computer modeling and a review of images taken by Voyager 1 and 2 and the Galileo orbiter of Jupiter’s moon Ganymede now suggest the existence of a giant impact so large that it covers almost half the moon’s surface.

The artist’s illustration of Ganymede on the right, based on our presently incomplete set of global images, shows this impact area as the circular dark region.

Many furrows, or trough formations, have been observed on the surface of Ganymede, one of the Jovian moons. This research group comprehensively reanalyzed image data of Ganymede obtained by NASA’s Voyager 1, Voyager 2, and Galileo spacecrafts. The results revealed that almost all of these furrows appear to be arranged in concentric rings centered around a single point, indicating that this global multiring structure may be the remains of a giant crater. The radial extent of the multiring structures measured along Ganymede’s surface is 7800 km. For comparison, the mean circumference of Ganymede is only 16,530 km. If correct, this is the largest crater yet identified in the Solar System. The previous record holder with a 1900 km radius is on Calisto, another Jovian moon.

The conclusion reached here is very uncertain, since we really do not have a high resolution global map of Ganymede. All three spacecraft were only able to send back a scattering of high resolution images. The global map is based on Earth observations and images from the Hubble Space Telescope.

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Lightning and mushballs on Jupiter

3:49 pm

Artist's illustration of Jupiter lightning
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Using data from Juno, scientists now theorize that Jupiter produces what they dub “shallow lightning” as well as ammonia-water hailstones dubbed “mushballs.”

The image to the right, cropped and reduced to post here, is only an artist’s illustration of the lightning. Sadly Juno’s camera doesn’t have the resolution to capture such flashes.

An unexpected form of electrical discharge, shallow lightning originates from clouds containing an ammonia-water solution, whereas lightning on Earth originates from water clouds.

Other new findings suggest the violent thunderstorms for which the gas giant is known may form slushy ammonia-rich hailstones Juno’s science team calls “mushballs”; they theorize that mushballs essentially kidnap ammonia and water in the upper atmosphere and carry them into the depths of Jupiter’s atmosphere.

As with the InSight results below, there is much uncertainty with these results, especially the hypothesis of mushballs. These features fit their present data from Juno, but we must remember that the data is still somewhat superficial.

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Jupiter’s south pole

10:59 am

The storms at the south pole of Jupiter
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Cool image time! The photo to the right, rotated and reduced to post here, was taken by Juno during its 28th close orbital fly-by of Jupiter, and then processed by citizen scientist Hemant Dara.

While not the first Juno image of the poles of Jupiter, this photo illustrates very well the evolution of the gas giant’s deep atmosphere as you move from the equator to the pole. From the equator to the high mid-latitudes the planet’s rotation, producing a day only 10 hours long, organizes that atmosphere into jet streams that form the bands that astronomers have spied from Earth since the first telescopes.

At the pole the influence of that rotation seems to wane, or at least influence the atmosphere differently, so that the storms seem to form randomly and incoherently.

The image also shows that there appear to be several types of storms at the south pole. Some appear as tight spirals, similar to hurricanes. Others appear chaotic, with no consistent shape, almost like clouds on Earth.

The processes that would explain all this are not yet understood, in the slightest, and won’t be until we get orbiters at Jupiter able to watch the atmosphere continuously, as we do here on Earth. Then it will be possible to assemble movies of the formation and dissipation of these storms, and begin (only begin) to decipher what causes them.

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New storm outbreak on Jupiter

10:00 am

Clyde's Spot
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A new storm, dubbed Clyde’s spot after its discoverer, developed suddenly in late May on Jupiter, and has been imaged by Juno during its most recent close fly-by of the gas giant planet.

The image to the right, cropped to post here, focuses in on this spot. It is the feature in the center of the full image, with the Great Red Spot to the upper left.

The new feature was discovered by amateur astronomer Clyde Foster of Centurion, South Africa. Early on the morning of May 31, 2020, while imaging Jupiter with his telescope, Foster noticed a new spot, which appeared bright as seen through a filter sensitive to wavelengths of light where methane gas in Jupiter’s atmosphere has strong absorption. The spot was not visible in images captured just hours earlier by astronomers in Australia.

On June 2, 2020, just two days after Clyde Foster’s observations, Juno performed its 27th close flyby of Jupiter. The spacecraft can only image a relatively thin slice of Jupiter’s cloud tops during each pass. Although Juno would not be travelling directly over the outbreak, the track was close enough that the mission team determined the spacecraft would obtain a detailed view of the new feature, which has been informally dubbed “Clyde’s Spot.”

The feature is a plume of cloud material erupting above the upper cloud layers of the Jovian atmosphere. These powerful convective “outbreaks” occasionally erupt in this latitude band, known as the South Temperate Belt

The coolest thing about this is that the storm was spotted by an amateur, using a ground-based telescope, within hours of its inception.

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That Jupiter Trojan comet-like asteroid was neither an asteroid nor a Trojan

9:14 am

Astronomers have now found that the asteroid that had suddenly become active, like a comet, and they had thought was part of the asteroids in Jupiter orbit called Trojans, was neither an asteroid nor a Trojan.

Instead, it is an actual comet captured in a strange unstable orbit around Jupiter.

[W]hen amateur astronomer Sam Deen used software on the Jet Propulsion Laboratory’s solar-system dynamics website to calculate the object’s orbit, he found P/2019 LD2 recently had a close encounter with Jupiter that left its orbit unstable. The model showed that the comet had likely been a Centaur, part of a family of outer solar system asteroids, with an orbit reaching out to Saturn. Then, on February 17, 2017, it passed about 14 million kilometers from Jupiter, an encounter that sent the comet on a wild ride and inserted it into an odd Jupiter-like orbit.

Yet although the swing past Jupiter put P/2019 LD2 into a Jupiter-like orbit, it didn’t move it near to one of the two Lagrange points where the combination of gravitational forces from Jupiter and the Sun hold Trojan asteroids. Instead of being 60° — one-sixth of the giant planet’s orbit — from Jupiter, P/2019 LD2 is only 21° ahead of Jupiter.

The orbit is unstable. It will bring the comet to within 3 million miles of Jupiter in 2063, but beyond that predictions are impossible. The exact closeness of that approach cannot be predicted with much precision, partly because of the chaotic nature of the orbit, and partly because of the random orbital changes that can occur because the comet is venting.

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Europa’s mysterious stained grooves

11:18 am

Europa's jumbled icepack
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From 1995 to 2003 the Galileo orbiter circled Jupiter 34 times. During those orbits the spacecraft made numerous close fly-bys of Jupiter’s moons, including eleven past the tantalizingly mysterious moon Europa.

The image to the right was taken during the eighth fly-by of Europa. It is one of three Galileo images of Europa that scientists have pulled from the Galileo archive and subjected to modern computer processing in order to improve what can be seen. The other two can be found here and here. From the release for the image to the right:

All three images were captured along the same longitude of Europa as Galileo flew by on Sept. 26, 1998, in the spacecraft’s 17th orbit of Jupiter (orbit E17). It was the eighth of Galileo’s 11 targeted flybys of Europa. High-resolution images were taken through a clear filter in grayscale (black and white). Using lower-resolution, color images of the same region from a different flyby (orbit E14), technicians recently mapped color onto the higher-resolution images.

In other words, they laid the colors from a lower resolution color image on top of the high resolution black & white image so that we could see these three images in color. The blue and white areas are made of up water ice, while the reddish areas are made up of “more non-ice materials.”

The vagueness for describing the non-ice materials is intentional, as scientists still do not know what they made of. They do believe that this material came from the planet’s interior, as the red material is always found aligned with the cracks, fissures, and grooves, as illustrated clear by this image.

What has always struck me about this surface of Europa since I first saw similar Galileo images back in 1998 and wrote about them for the magazine The Sciences is how much it resembles the Arctic ice pack as seen by early explorers during their attempts to reach the North Pole, jumbled jigsaw pieces of ice packed together but moving slowly so that the cracks between them shift and change over time.

The resemblance adds weight to the theory that there is a liquid ocean below Europa’s icepack, and the red material hints at some intriguing chemistry coming from that ocean.

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Jupiter in glorious color

9:21 am

Jupiter in glorious color
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Cool image time! The photograph on the right, reduced to post here, was color enhanced by citizen scientist Emma Walimaki from the original Juno image in order to bring out the features and storms visible in the upper storm layers of Jupiter.

The photo was taken during Juno’s 25th close fly-by of the gas giant, and thus we are only seeing a small portion of Jupiter’s sphere.

In comparing this image with the original, it appears that Walimaki simply made the colors that were already there brighter and more distinctive. Thus, these colors represent real data. Jupiter’s cloud tops are really blue, orange, tan, and brown, unlike Earth’s consistently and boringly white water clouds.

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Juno’s first measurement of water content on Jupiter

3:40 pm

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.

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Europa Clipper faces budget overruns

10:25 am

NASA’s $4.25 billion dollar mission to orbit the Jupiter moon Europa now faces cost overruns that threaten its launch in 2023.

The management of NASA’s Europa Clipper mission, facing dwindling cost reserves while still years away from launch, is looking at cost saving options that would preserve the mission’s science.

In a Feb. 3 presentation at a meeting of the Outer Planets Assessment Group in Houston, Jan Chodas, project manager for Europa Clipper at the Jet Propulsion Laboratory, said she was looking for ways to restore cost reserves that had declined precipitously in the last year.

Chodas said that Europa Clipper had met a JPL recommendation of 25% cost reserves, known at the lab as unallocated future expenses (UFE), when it completed a final “delta” preliminary design review in June 2019. By November, though, those reserves had fallen to just 12%, a level deemed “unacceptably low” for a mission not scheduled for launch until at least 2023.

To save money, they are “streamlining hardware testing and scaling back work on flight spare hardware. The project has also reduced the frequency of meetings of the mission’s science team.”

When the reserves in a government budget get this low, it almost always guarantees that the budget will go over. When the reserves get this low this early in the project, it almost always guarantees that the budget will go over, by a lot.

There have been other indications that Europa Clipper’s budget is in trouble. In March NASA canceled one science instrument to save money.

Making matter worse has been our lovely Congress, which has required this mission fly on its bloated, over-budget, and behind schedule SLS rocket, a mandate that is also costing the project an additional $1.5 billion (for the launch) while threatening its launch date (because of SLS delays). NASA would rather have the option to launch Clipper on the more reliable commercial and already operational Falcon Heavy, for about $100 million, thereby saving more than a billion dollars while guaranteeing its launch date. Congress so far has refused to budge, and has in fact insisted that the mission be delayed several years if necessary for getting it on SLS.

Meanwhile, Clipper itself is doing what too many big NASA projects routinely do, go overbudget.

Our federal government. Doesn’t its management skills just warm your heart?

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A new Juno flyover movie above Jupiter

10:01 am

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.

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First image of Ganymede’s north pole

10:26 am

Ganymede's north polar region

During Juno’s 24th close approach to Jupiter the spacecraft was able to take the first images ever of the north pole of Ganymede, the largest moon in the solar system. The image to the right was processed by citizen scientist Roman Tkacenko, and shows a variety of light and dark features.

The Juno science team decided for some reason to highlight a different set of images processed by citizen scientist Gerald Eichstädt, using the same data. I prefer Tkacenko’s version, because he focused in on the planet itself, making it easier to see what’s there.

In either case, however, the fuzziness of the image reminds me of planetary astronomy in my early childhood. Images like this, taken by telescopes on Earth, were the best we had of any planet beyond the Moon. Made it very hard to understand what was there, or what it meant.

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Movie of Jupiter’s south pole storms

9:03 am

Clip from animation of Jupiter's south polar storms

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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New storm spotted at Jupiter’s south pole

8:31 am

New cyclone at Jupiter's south pole
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.

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