Tag: Jupiter

Gerald Eichstädt at the Juno image site has produced the first attempt to assemble a movie of Juno images of the same area on Jupiter in order to show its changing weather.

JunoCam has been seeing this scene about six times from very different perspectives between about 2017-09-01T22:03 and about 2017-09-01T22:19, hence a over a little more than 15 minutes.

This animation is a first attempt to reproject the six images to a similar common perspective in order to reveal some dynamical information.

An movie covering only 15 minutes won’t show much change, but it is a start. He also notes that in making the different images match up he likely introduced some artifacts that are not real.

The uncertainty of science: Scientists analyzing the data sent back by Juno have found that the system for generating Jupiter’s aurora does not appear to be same as the process that creates auroras on Earth.

The science here is a bit complicated. Suffice it to say that Jupiter’s aurora seems produced by a much more complex process, which actually should not have surprised anyone, considering how much larger Jupiter is and more powerful its magnetic field.

Cool image time! The raw images taken during Juno’s seventh close fly-by of Jupiter have been released. The image on the right, reduced in resolution to post here, was reprocessed by Gerald Eichstädt and shows the gas giant’s south polar region.

It is worthwhile comparing this with previous south pole images, as well as other images from this fly-by reprocessed by Eichstadt. I want to know whether anyone can identify specific storms and show how they have changed over time. Unfortunately, Juno’s orbit is large, and so it only drops in close every 53 days, allowing for these storms to change a great deal, and thus making it more difficult to link images of the same changing storm. Moreover, the images don’t necessarily show the same longitudes on Jupiter, making this even more difficult.

Nonetheless, to gain a real understanding of Jupiter’s atmosphere will require a clear understanding of the pace in which its storms and atmosphere change. These images might give us our first glimpse of this process.

Using two Juno images of the same area, taken at slightly different times, scientists have produced what might be the first very short gif animation showing the changing circulation patterns in Jupiter’s atmosphere.

The animation is only two images long, so in a sense it isn’t a movie but a blink comparison. Moreover, the difference in circulation patterns between the two images is not strongly evident, partly because the two images have different resolution and somewhat different lighting. Nonetheless, this animation foretells what will should become possible with time, as Juno’s mission continues. Eventually its images will show the changes in the gas giant’s storms.

Cool image time! The Juno image on the right, cropped to show here, focuses in on one of Jupiter’s mid-sized storms near its high northern latitudes and just on the edge of the chaotic polar region.

This storm is a long-lived anticyclonic oval named North North Temperate Little Red Spot 1 (NN-LRS-1); it has been tracked at least since 1993, and may be older still. An anticyclone is a weather phenomenon where winds around the storm flow in the direction opposite to that of the flow around a region of low pressure. It is the third largest anticyclonic oval on the planet, typically around 3,700 miles (6,000 kilometers) long. The color varies between red and off-white (as it is now), but this JunoCam image shows that it still has a pale reddish core within the radius of maximum wind speeds.

Be sure to take a look at the full image, which provides a bit of context.

Juno has successfully completed its sixth close fly-by of Jupiter, this time dipping down to within 2,200 miles of the gas giant’s cloud tops and about 5,600 miles above the Great Red Spot.

All science instruments worked flawlessly, according the NASA press release. Images should become available in the next few days.

The next close fly-by will occur in September.

Cool image time! On the right is a cropped and reduced resolution section from this image from Juno. It shows the top of some of Jupiter’s clouds, swirling about chaotically.

What I find most fascinating is how this image reveals the different elevations of some of these cloud belts. The swirling clouds on the left and bottom of the image are clearly higher than the dark areas to the top and right. They are in fact casting their shadows on those lower cloud-tops.

To really understand the interactions taking place here, however, will require satellites capable of continually tracking these clouds over time. Unfortunately, Juno cannot do this. Though it will provide us periodic snapshots of specific areas, its long 53-day orbit means that it will not return to view the same areas very frequently. Making movies of the evolution of these clouds will be difficult, if not impossible.

Cool image time! The image on the right, reduced to post here, shows Jupiter’s south pole and much of its southern hemisphere. It was taken during Juno’s last orbital fly-by of the gas giant’s cloud tops last week, and has been enhanced by Fevig-58, an ordinary citizen who downloaded the raw image and then uploaded his enhanced version to the Juno website.

It is definitely worthwhile taking a close look at the full resolution image. At the top its shows the horizontally banded Jupiter at equatorial- and mid-latitudes that has been that planet’s familiar face for centuries. In the middle is the transitional region from those horizontal bands to the chaotic polar regions. And at the bottom is the pole, where there the storms appear to follow no pattern and form a mish-mash.

One thing about Jupiter’s pole. It appears very different than Saturn’s. While I am certain they will find a vortex of some kind there, so far there is no indication of a coherent jet stream, as seen by Saturn’s hexagon. This once again demonstrates the one unbroken rule of planetary science that has been found with every planetary mission to every planetary body, whether they be pebbles, asteroids, dwarf planets, gas giants, or moons: Every single one of them is different and unique. They might fall into a single category, say gas giants, but each has its own unique features that make it different from every other member of that category.

The Juno science team today released their first research results since the spacecraft entered orbit around Jupiter in July 2016.

“Although many of the observations have terrestrial analogs, it appears that different processes are at work creating the auroras,” said SwRI’s Dr. Phil Valek, JADE instrument lead. “With JADE we’ve observed plasmas upwelling from the upper atmosphere to help populate Jupiter’s magnetosphere. However, the energetic particles associated with Jovian auroras are very different from those that power the most intense auroral emissions at Earth.”

Also surprising, Jupiter’s signature bands disappear near its poles. JunoCam images show a chaotic scene of swirling storms up to the size of Mars towering above a bluish backdrop. Since the first observations of these belts and zones many decades ago, scientists have wondered how far beneath the gas giant’s swirling façade these features persist. Juno’s microwave sounding instrument reveals that topical weather phenomena extend deep below the cloudtops, to pressures of 100 bars, 100 times Earth’s air pressure at sea level.

“However, there’s a north-south asymmetry. The depths of the bands are distributed unequally,” Bolton said. “We’ve observed a narrow ammonia-rich plume at the equator. It resembles a deeper, wider version of the air currents that rise from Earth’s equator and generate the trade winds.”

Juno is mapping Jupiter’s gravitational and magnetic fields to better understand the planet’s interior structure and measure the mass of the core. Scientists think a dynamo — a rotating, convecting, electrically conducting fluid in a planet’s outer core — is the mechanism for generating the planetary magnetic fields. “Juno’s gravity field measurements differ significantly from what we expected, which has implications for the distribution of heavy elements in the interior, including the existence and mass of Jupiter’s core,” Bolton said. The magnitude of the observed magnetic field was 7.766 Gauss, significantly stronger than expected. But the real surprise was the dramatic spatial variation in the field, which was significantly higher than expected in some locations, and markedly lower in others. “We characterized the field to estimate the depth of the dynamo region, suggesting that it may occur in a molecular hydrogen layer above the pressure-induced transition to the metallic state.”

What I want to see is a depth map showing where Jupiter’s atmosphere ends and its solid core begins. I expect Juno will eventually be able to give us a first glimpse.

Juno has successfully completed its fifth flyby and orbit of Jupiter, dipping to within 2,200 miles of the top of the gas giant’s atmosphere.

The next flyby is set for July 11, and will zip across directly above the Great Red Spot.

Juno yesterday completed its fifth close flyby of Jupiter, dipping to within 2,700 miles of the gas giant’s clouds.

All instruments were working. There will be pictures, but the bulk of the science will be data collection, not pretty pictures.

The scientists and engineers running the Juno mission to Jupiter have decided to keep the spacecraft in its 53-day orbit for the rest of its mission rather than fire its engines to lower the orbit to its planned 14 days duration.

The original Juno flight plan envisioned the spacecraft looping around Jupiter twice in 53-day orbits, then reducing its orbital period to 14 days for the remainder of the mission. However, two helium check valves that are part of the plumbing for the spacecraft’s main engine did not operate as expected when the propulsion system was pressurized in October. Telemetry from the spacecraft indicated that it took several minutes for the valves to open, while it took only a few seconds during past main engine firings. “During a thorough review, we looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. “The bottom line is a burn represented a risk to completion of Juno’s science objectives.”

There are both pros and cons for using this longer orbit, detailed at the link, with.the most important being that doing nothing avoids losing the mission entirely.

Juno is set to make its fourth close fly-by of Jupiter today, dipping to within 2,670 miles of the gas giants cloud tops.

The Juno science team continues to analyze returns from previous flybys. Revelations include that Jupiter’s magnetic fields and aurora are bigger and more powerful than originally thought and that the belts and zones that give the gas giant’s cloud top its distinctive look extend deep into the planet’s interior. Peer-reviewed papers with more in-depth science results from Juno’s first three flybys are expected to be published within the next few months. Also, JunoCam, the first interplanetary outreach camera, is now being guided with the assistance from the public — people can participate by voting for what features on Jupiter should be imaged during each flyby.

On December 11 Juno successfully completed its third close flyby of Jupiter.

They have released one quite spectacular image taken during the close approach. Expect more to follow soon.

Though they continue to say that they are still considering firing the spacecraft’s main engine to lower and shorten the orbit, I am getting the impression that they are increasingly leaning to leaving things as they are. While this longer orbit will produce larger gaps in their data of the gas giant’s atmosphere (53 days between close approaches versus 14 days), it will also allow them to tract changes over a much longer time period. Considering the risk of a catastrophic failure should they fire the questionable engine, this choice seems quite reasonable.

The Juno science team prepares for the next close flyby of Jupiter on December 11.

At the time of closest approach (called perijove), Juno will be about 2,580 miles (4,150 kilometers) above the gas giant’s roiling cloud tops and traveling at a speed of about 129,000 mph (57.8 kilometers per second) relative to the planet. Seven of Juno’s eight science instruments will be energized and collecting data during the flyby. “This will be the first time we are planning to operate the full Juno capability to investigate Jupiter’s interior structure via its gravity field,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “We are looking forward to what Jupiter’s gravity may reveal about the gas giant’s past and its future.”

Mission managers have decided not to collect data with the Jovian Infrared Auroral Mapper (JIRAM) instrument during the December flyby, to allow the team to complete an update to the spacecraft software that processes JIRAM’s science data. A software patch allowing JIRAM’s operation is expected to be available prior to the next perijove pass (PJ4) on Feb. 2, 2017.

It increasingly appears they do not want to risk firing the spacecraft’s main engine to shorten the 53 day orbit to 14 days because of a fear that the burn could fail catastrophically. This means that Juno’s mission will be extended significantly because it will take longer to gather data with such a long orbit.

Cool image time! The image on the right shows what anyone can do if they want to play with images that have been taken by the Juno spacecraft. On top is the raw Juno image of a storm on Jupiter. On the bottom is that same storm after significant processing by an ordinary citizen. A larger version can be seen here.

While the Juno science team’s policy of making all their raw images available to the public is routine for a NASA mission, they are doing something a bit different by allowing the public to play with the images and then upload them on a Juno website for everyone to see. While some of the subsequent images have been a little silly, the image on the right illustrates how this policy can help scientists (and the public) better study the atmosphere on Jupiter. The processing has brought out all the storm’s swirls and twirls, and shown clearly how chaotic the storms are in Jupiter’s high latitudes.

The scientists don’t have the resources or the time to do this kind of processing on every image, or even every piece of every image. Allowing the public to do it will increase the variety of results and make it more likely for everyone to gain some understanding of what is going on in the gas giant’s atmosphere. Or not, but then that’s okay, as a realization that we don’t understand something is the first step towards wisdom and real knowledge.

Having successfully left safe mode, engineers had Juno do a 31 minute engine burn on Tuesday to adjust its orbit using its smaller thrusters.

The burn, which lasted just over 31 minutes, changed Juno’s orbital velocity by about 5.8 mph (2.6 meters per second) and consumed about 8 pounds (3.6 kilograms) of propellant. Juno will perform its next science flyby of Jupiter on Dec. 11, with time of closest approach to the gas giant occurring at 9:03 a.m. PDT (12:03 p.m. EDT). The complete suite of Juno’s science instruments, as well as the JunoCam imager, will be collecting data during the upcoming flyby.

That they will definitely collect data during the December 11 flyby means that they are going to delay again the main engine burn that will reduce the spacecraft’s orbit to 14 days, its official science orbit. This also means that they are still uncomfortable firing that main engine. It is also not clear from the press release whether this burn was planned, or was added to compensate for the main engine issues.

The vagueness makes me think that Juno has some serious issues that they haven’t yet told us about.

Cool image time! Even though Juno has been unable to gather any additional data since its first close approach of Jupiter in August because of technical problems, the science team has set up its website to allow the public to download the images produced so far, process those images, and then upload them to the site for the world to see.

The image to the right, reduced in resolution to show here, is one example of the many different processed images produced by interested members of the general public. It highlights the seemingly incoherent storms that are raging at Jupiter’s south pole.

To the left is a cropped section of the full resolution image. It shows the complex transition zone between the darker polar regions and the brighter band that surrounds it. This chaotic atmospheric behavior is something that no climate scientist has ever seen before. It will take decades of research to untangle and even begin to understand what is happening.