Tag: Europa

New data suggests Europa’s surface is constantly changing

9:26 am

Webb data showing variations on Europa's surface
Click for original graphic.

The uncertainty of science: Using data collected by the Webb Space Telescope combined with modeling and lab experiments, scientists now think they have found evidence that Europa’s surface is constantly changing, with materials from its interior being brought to the surface.

This new study found crystalline ice on the surface as well as at depth in some areas on Europa, especially an area known as Tara Regio. “We think that the surface is fairly porous and warm enough in some areas to allow the ice to recrystallize rapidly,” said Dr. Richard Cartwright, lead author of the paper and a spectroscopist at Johns Hopkins University’s Applied Physics Laboratory. “Also, in this same region, generally referred to as a chaos region, we see a lot of other unusual things, including the best evidence for sodium chloride, like table salt, probably originating from its interior ocean. We also see some of the strongest evidence for CO2 and hydrogen peroxide on Europa.”

…“Our data showed strong indications that what we are seeing must be sourced from the interior, perhaps from a subsurface ocean nearly 20 miles (30 kilometers) beneath Europa’s thick icy shell,” said [Dr. Ujjwal Raut of the Southwest Research Institute and co-author of the paper]. “This region of fractured surface materials could point to geologic processes pushing subsurface materials up from below. When we see evidence of CO2 at the surface, we think it must have come from an ocean below the surface.”

The graphic to the right shows the detected variations across the surface of Europa, based on the Webb spectroscopic data. It also illustrates nicely the coarseness of this data, its lack of resolution, and the uncertainties involved. The scientists have found evidence that suggests the surface is changing, but the key word here is “suggests”. They have not yet directly seen any actual changes, such as changes between two images taken at different times.

Nonetheless, the data does point in the right direction. Moreover, it would be far more unlikely if nothing on Europa changed. The fundamental question that remains unanswered is how fast things change there. And we won’t have any chance to answer this question until Europa Clipper enters Jupiter orbit in 2030 and begins multiply fly-bys of Europa.

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The Europa Clipper team prepares for Mars fly-by

8:52 am

Europa Clipper's route to Jupiter
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As planned, Europa Clipper is set to do a very close fly-by of Mars on March 1, 2025, zipping past the red planet at a speed of 15.2 miles per second only 550 miles above its surface. The graphic to the right shows the spacecraft’s planned route to Jupiter, including an additional fly-by of Earth in 2026.

During this first fly-by the science team will test two of Europa Clipper’s instruments.

About a day prior to the closest approach, the mission will calibrate the thermal imager, resulting in a multicolored image of Mars in the months following as the data is returned and scientists process the data. And near closest approach, they’ll have the radar instrument perform a test of its operations — the first time all its components will be tested together. The radar antennas are so massive, and the wavelengths they produce so long that it wasn’t possible for engineers to test them on Earth before launch.

The spacecraft launched with transistors not properly hardened for the hostile environment around Jupiter. Engineers claimed these would “heal” themselves once in Jupiter orbit. No word on whether there has been any issue from these components since launch.

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Io’s volcanoes get their lava from separate magma chambers, not a global underground ocean of magma

11:11 am

Io's interior as presently theorized
Click for original animation.

Using data collected from Juno’s multiple fly-bys of the Jupiter moon Io, scientists now hypothesize that the moon does not have a global underground ocean of magma, feeding its many volcanoes, but that instead each volcano is fed its lava from a separate magma chamber.

The graphic to the right illustrates the present conclusion. You can read the paper here [pdf]. From the press release:

The Juno team compared Doppler data from their two flybys with observations from the agency’s previous missions to the Jovian system and from ground telescopes. They found tidal deformation consistent with Io not having a shallow global magma ocean.

“Juno’s discovery that tidal forces do not always create global magma oceans does more than prompt us to rethink what we know about Io’s interior,” said lead author Ryan Park, a Juno co-investigator and supervisor of the Solar System Dynamics Group at JPL. “It has implications for our understanding of other moons, such as Enceladus and Europa, and even exoplanets and super-Earths. Our new findings provide an opportunity to rethink what we know about planetary formation and evolution.” [emphasis mine]

The highlighted words indicate the significance of this data. It possibly suggests that the underground oceans of water that have been theorized for these other moons — where life could possibly exist — might be mistaken. Instead, they might have smaller pockets of water, similar to Io’s many magma chambers.

Everything here however is uncertain, including these new conclusions about Io. We just don’t have enough data from any of these moons to make any definitive conclusions.

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JPL unveils website for viewing all high resolution imagery so far taken of Europa

9:29 am

In anticipation of the eventual arrival of Europa Clipper in orbit around Jupiter to begin its close investigation of that planet’s moon Europa, JPL yesterday unveiled a website that allows a view to quickly find and review all the high resolution imagery so far taken of Europa by the Jupiter orbiters, Voyager, Galileo, and Juno.

You can visit the Europa Trek portal website here.

The announcement touts the webpage’s ability to take viewers on “fly-overs” of the terrain, but that’s just a bell and whistle claim of little importance. More significant is the easy access this webpage provides to all that imagery, organized in context with a global map of the planet. Not only can anyone quick find interesting features, you can do so within the global context of the whole planet. In addition, the page provides detailed commentary about each image.

When Europa Clipper arrives this portal will be invaluable in deciphering the significance of every new image and datapoint.

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SpaceX’s Falcon Heavy launches NASA’s Europa Clipper mission

9:50 am

Europa's approximate orbit around Jupiter
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SpaceX’s Falcon Heavy rocket this morning successfully launched NASA’s Europa Clipper mission on its way to Jupiter, the rocket lifting off from the Kennedy Space Center in Florida.

In order to get the energy to reach Jupiter, none of the Falcon Heavy’s first stage boosters were recovered today. The two side boosters completed their sixth and final flights with this mission, while the core booster completed its first launch. The only parts of the rocket that will be recovered and reused were the two fairing halves.

To get to Jupiter, the spacecraft will make first a fly-by of Mars in February 2025, and then a fly-by of Earth in December 2026. It will arrive in Jupiter orbit in April 2030, where its orbit will be adjusted to fly close past Europa many times in order to study it closely, as shown by the graphic on the right. It will not going into orbit around the planet because that would place it permanently inside the high radiation environment around Jupiter. This is especially important because the spacecraft has installed transistors that were not properly hardened for that environment.

The leaders in the 2024 launch race:

98 SpaceX
45 China
11 Russia
11 Rocket Lab

American private enterprise now leads the rest of the world combined in successful launches 115 to 68, while SpaceX by itself now leads the entire world, including American companies, 98 to 85.

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In approving Europa Clipper’s launch, NASA and JPL claim its non-spec transistors will “heal” themselves in Jupiter orbit

9:12 am

Europa in true color
Europa in true color, taken by Juno September 2022.
Click for full image.

In making the decision to allow Europa Clipper to be launched on a Falcon Heavy on October 10, 2024, NASA and JPL officials explained that after several months of testing, they believe the improperly hardened transistors installed throughout the orbiter will “heal” themselves while in the low radiation portions of its orbit around Jupiter.

[The testing] showed the transistors in question will, in effect, heal themselves during the 20 days between the high radiation doses the probe will receive during each of 49 close flybys of Europa, all of them deep in Jupiter’s powerful magnetic field and radiation environment.

In addition, onboard heaters can be used as needed to raise the temperature of affected transistors, improving the recovery process. “After extensive testing and analysis of the transistors, the Europa Clipper project and I personally have high confidence we can complete the original mission for exploring Europa as planned,” said Jordan Evans, Europa Clipper project manager at NASA’s Jet Propulsion Laboratory.

I hope this analysis is right, though I fear there is a lot of wishful-thinking involved. It could be however that this testing, in combination with what engineers have learned during Juno’s so-far 64 orbits around Jupiter, might have reassured them.

We however will not know for sure until Europa Clipper is on its way and reaches Jupiter in 2030.

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NASA confirms Europa Clipper launch on October 10, 2024 with questionable transistors

9:21 am

NASA yesterday confirmed that it has decided to go ahead with the October 10, 2024 launch of its $5+ billion Europa Clipper mission to Jupiter, despite the installation of transistors on the spacecraft that the agency knows are not properly hardened for that harsh environment.

Those transistors were built by a German company as part of equipment used by the spacecraft’s electrical system. Apparently that company hired a subcontractor to furnish the transistors, which failed to make them to the right specifications. Subsequent testing found that it is quite likely that at least some of the transistors will fail when Europa Clipper reaches Jupiter orbit.

It appears that NASA decided that the issue risk was small enough for the mission to achieve its minimal expected results, and decided the cost of delay and bad publicity replacing the transistors before launch would be worse than the limited science payoff and bad publicity that would take place years hence, when those transistors fail.

Remember this story in in 2030 when Europa Clipper enters Jupiter orbit and begins to experience problems.

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NASA leans toward launching Europa Clipper as scheduled, despite transistor issue

9:26 am

Though the final decision will be made in early September, NASA revealed today in a short post that management is leaning towards launching the multi-billion Europa Clipper mission as scheduled on October 10, 2024, despite a very recently discovered transistor issue where the transistors were not properly hardened in construction for the harsh radiation environment surrounding Jupiter.

The next major milestone for Clipper is Key Decision Point E on Monday, Sept. 9, in which the agency will decide whether the project is ready to proceed to launch and mission operations. NASA will provide more information at a mission overview and media briefing targeted for that same week.

The Europa Clipper mission team recently conducted extensive testing and analysis of transistors that help control the flow of electricity on the spacecraft. Analysis of the results suggests the transistors can support the baseline mission. [emphasis mine]

The highlighted sentence suggests NASA officials have weighed the option between launching on time with a limited ability to do science once at Jupiter versus delaying the launch years to fix the transistors, and are now favoring the former option. The cost of delay would be high and long, and NASA officials might believe the bad press for that option would be much greater than a mission that only achieves its bare minimum results. For example, to admit publicly that NASA installed transistors that were not space-hardened when that necessity has been known about since the 1960s would be as embarrassing to the agency as it was for Boeing when it discovered it had installed flammable tape in its Starliner capsule. NASA management might be leaning to letting a flawed multi-billion dollar project launch, knowing its capabilities are quite limited, in order to avoid that embarrassment.

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Computer models suggest there is no life in Europa’s underground ocean

11:22 am

The uncertainty of science: Several different computer simulations now suggest that the underground ocean inside the Jupiter moon Europa is inert and likely harbors no existing lifeforms.

He and his colleagues constructed computer simulations of Europa’s seafloor, accounting for its gravity, the weight of the overlying ocean and the pressure of water within the seafloor itself. From the simulations, the team computed the strength of the rocks about 1 kilometer below the seafloor, or the stress required to force faults in the seafloor to slide and expose fresh rock to seawater.

Compared with the stress applied to the seafloor by Jupiter’s gravity and by the convection of material in Europa’s underlying mantle, the rocks comprising Europa’s seafloor are at least 10 times as strong, Byrne said. “The take home message is that the seafloor is likely geologically inert.”

A second computer model also suggested that the moon’s deep magna is not capable to pushing upward into that sea, further reinforcing the first model that the sea is geological inert, lacking the heat or energy required for life.

Though unconfirmed and uncertain, these results when looked at honestly make sense. Europa is a very cold world. An underground ocean might exist due to tidal forces imposed by Jupiter, but that dark and sunless ocean is also likely to be very hostile to life. Not enough energy to sustain it.

Like the water imagined to exist at poles of the Moon, we go to Europa on the hope of finding life, even if that hope is very ephermal.

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Scientists: Europa produces oxygen on its surface, but less than expected

10:18 am

Graphic of Europa
Click for original image.

The uncertainty of science: Scientists using data from a 2022 flyby of the Jupiter moon Europa by the orbiter Juno have determined that the moon produces about 1,000 tons of oxygen every 24 hours on its surface, a large amount but less than most predictions based on previous indirect observations.

The paper’s authors estimate the amount of oxygen produced to be around 26 pounds every second (12 kilograms per second). Previous estimates range from a few pounds to over 2,000 pounds per second (over 1,000 kilograms per second). Scientists believe that some of the oxygen produced in this manner could work its way into the moon’s subsurface ocean as a possible source of metabolic energy.

You can read the paper here. The graphic shows the basic process, as presently theorized. What remains unknown is how or even if that oxygen is transported downward to the theorized underground ocean of liquid water. That the amount created is on the very low end of previous estimates suggests that there will be less free oxygen to support life in that ocean than expected.

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Juno’s closest image of Europa suggests recent surface activity

11:18 am

Juno's best image of Europa
Click for original image.

Analysis by scientists of the closest image of Europa taken during Juno’s close-fly on September 29, 2022 suggests that a particular strange feature, dubbed the “platypus” due to its shape, might be very young and indicate recent surface activity that could be related to underground liquid water.

That picture, reduced and sharpened to post here, is to the right. It is figure 2 of the paper. The description of this photo from the abstract:

Intricate networks of cross-cutting ridges and lineated bands surround an intriguing 37 km (east-west) by 67 km (north-south) chaos feature with a concentric fracture system, depressed matrix margins, and low-albedo materials potentially associated with brine infiltration. The morphology and local relief of the chaos feature are consistent with formation in the collapse of ice overlying a salt-rich lens of subsurface water. Low-albedo deposits, similar to features previously associated with hypothesized cryovolcanic plume activity, flank nearby ridges. The SRU’s high-resolution view of many types of features in a single image allows us to explore their regional context and greatly improve the geologic mapping of this part of Europa’s surface. The image reveals several relatively youthful features in a potentially dynamic region, providing baselines for candidate locations that future missions can investigate for present day surface activity.

SRU is Juno’s Stellar Reference Unit camera, designed to take pictures using only the low light of Jupiter reflected onto nighttime surfaces of Jupiter’s moons. It took this photo when Juno was only 256 miles above the surface.

This feature will obviously become a prime target for Europa Clipper when it arrives into orbit around Jupiter in April 2030. From this vantage point — safer than continuous exposure to Jupiter’s magnetosphere while in orbit around Europa — the spacecraft will do 44 close-flys of the moon.

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Webb infrared data suggests Europa’s C02 comes from within

9:41 am

Europa as seen by Webb's near-infrared camera
Europa as seen by Webb’s near-infrared camera.
Click for original image.

Two different research papers, using infrared data from the Webb Space Telescope, have independently concluded that the carbon dioxide previously detected on the surface of Europa is found concentrated in the same region, and has the earmarks of coming from beneath the surface.

In one study, Samantha Trumbo and Michael Brown used the JWST [Webb] data to map the distribution of CO2 on Europa and found the highest abundance of CO2 is located in Tara Regio – a ~1,800 square kilometer region dominated by “chaos terrain,” geologically disrupted resurfaced materials. According to Tumbo and Brown, the amount of CO2 identified within this recently resurfaced region – some of the youngest terrain on Europa’s surface – indicates that it was derived from an internal source of carbon. This implies that the CO2 formed within Europa’s subsurface ocean and was brought to the surface on a geologically recent timescale. However, the authors say that formation of CO2 on the surface from ocean-derived organics or carbonates cannot be entirely ruled out. In either interpretation, the subsurface ocean contains carbon.

In an independent study of the same JWST data, Geronimo Villanueva and colleagues found that the CO2 on Europa’s surface is mixed with other compounds. Villanueva et al. also find the CO2 is concentrated in Tara Regio and interpret that as demonstrating that the carbon on the moon’s surface was sourced from within. The authors measured the ice’s 12C/13C isotopic ratio, but could not distinguish between an abiotic or biogenic source. Moreover, Villanueva et al. searched for plumes of volatile material breaching moon’s icy crust. Although previous studies have reported evidence of these features, the authors did not detect any plume activity during the JWST observations. They argue that plume activity on Europa could be infrequent, or sometimes does not contain the volatile gasses they included in their search.

As always, these conclusion must be viewed with some skepticism, as the data is somewhat sparse and coarse. Webb’s resolution is not enough to truly pinpoint the source location with great accuracy, and the conclusion that the CO2 comes from underground depends on many assumptions. For example, in the image above, the white area roughly corresponds to Tara Regio, but with very large margins.

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Jupiter and two of its Moons, as seen by Cassini during 2018 fly-by

4:41 pm

Cool video time! Back in December 2000 the spacecraft Cassini made a fly-by of Jupiter on its way to Saturn, which it then orbited from 2004 to 2017. In 2018 JPL scientist Kevin Gil took the images from that flyby to create a short movie, first showing two of Jupiter’s moons, Io and Europa, as they drifted above the Great Red Spot.

Then, for the second half of the movie Gil used Cassini images taken when in orbit around Saturn to show the moon Titan moving across the rings of Saturn.

I have embedded this short video below. If I had posted this back in 2018, I don’t remember. No matter. It is amazing enough to watch again.

Hat tip BtB’s stringer Jay.
» Read more

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Delays threaten Europa Clipper mission

8:57 am

A variety of issues delaying completion of the science instruments on the Europa Clipper mission are now threatening to prevent the spacecraft from meeting its 2024 launch date.

[W]ith less than two years to go before launch, only three of those instruments have been installed on the main spacecraft body, and five haven’t yet arrived at JPL.

Some context: Europa Clipper has been under development since 1997, though actual design work did not begin until 2013, nine years ago. It presently has a budget of $4.25 billion (more than double its first proposed budget of $2 billion). Yet now, less than years from launch, seven of ten instruments are behind schedule?

What is really disgusting about this story is that it is par for the course for NASA, which almost never finishes anything on time or on budget.

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Europa in true color

9:37 am

Europa in true color
Click for full image.

The photo to the right, cropped and reduced to post here, was taken on September 29, 2022 by the Jupiter orbiter Juno during its close fly-by of Europa. Citizen scientist Bjorn Jonsson has processed it to bring out the details. From his caption:

This is an approximately true color/contrast, reprocessed version of Europa image PJ45_1. It is more carefully processed than the version I posted very shortly after the raw image data was released. The color should be fairly close to Europa’s real color and probably slightly more accurate than the color of the earlier version I posted. North is up.

The Sun is coming from the right, so those are craters in the upper left, close to the shadowed limb of the planet. The red color has been known for decades, and appears in many cases to be seepage coming up from the many meandering ridges that criss-cross the planet’s surface. Their chemistry/make-up is not fully known at this time.

Juno came within 219 miles of Europa, the closest any spacecraft has come since the Galileo orbiter circled Jupiter in the 1990s. I was expecting close-up images of the surface, from that close distance, but have not yet seen any. Instead, most of the images released and processed by citizen scientists have been global images from farther away. Thus, at this moment it does not appear Juno took pictures at this closest distance.

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NASA releases first Juno image from the first close fly-by of Europa in decades

10:00 am

First released Juno image of Europa
Click for full image.

Kevin Gill's processed Juno image of Europa
Click for full image.

NASA yesterday released the first image from the successful close fly-by by Juno of Jupiter’s moon Europa since the 1990s. That photo, reduced and sharpened, is above.

The first picture NASA’s Juno spacecraft took as it flew by Jupiter’s ice-encrusted moon Europa has arrived on Earth. Revealing surface features in a region near the moon’s equator called Annwn Regio, the image was captured during the solar-powered spacecraft’s closest approach, on Thursday, Sept. 29, at 2:36 a.m. PDT (5:36 a.m. EDT), at a distance of about 219 miles (352 kilometers).

This is only the third close pass in history below 310 miles (500 kilometers) altitude and the closest look any spacecraft has provided at Europa since Jan. 3, 2000, when NASA’s Galileo came within 218 miles (351 kilometers) of the surface.

Meanwhile, the raw images have been pouring in, and citizen scientists have been quickly processing them. The photo to the right is only one example, created by Kevin Gill. I have cropped it to show one section in full resolution.

Expect many more processed images, especially those taken at closest approach, in the coming days.

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Webb infrared image of Jupiter & Europa

3:36 pm

Jupiter and Europa as seen by Webb
Click for full image.

During the commissioning phase after deployment, the James Webb Space Telescope took images of Jupiter and several asteroids in order test the telescope’s instruments. The photo to the right, cropped and reduced to post here, shows both Jupiter and its moon Europa to the left.

Fans of Jupiter will recognize some familiar features of our solar system’s enormous planet in these images seen through Webb’s infrared gaze. A view from the NIRCam instrument’s short-wavelength filter shows distinct bands that encircle the planet as well as the Great Red Spot, a storm big enough to swallow the Earth. The iconic spot appears white in this image because of the way Webb’s infrared image was processed.

…Clearly visible at left is Europa, a moon with a probable ocean below its thick icy crust, and the target of NASA’s forthcoming Europa Clipper mission. What’s more, Europa’s shadow can be seen to the left of the Great Red Spot. Other visible moons in these images include Thebe and Metis.

The false color differences indicated differences in heat but it is not explained whether brighter is colder or warmer in this photo.. As one of my readers below correctly notes, Europa’s shadow tells us that darker is cooler. This one image shows that the Red Spot and Jupiter’s equatorial regions and poles are generally warm.

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Scientists: Enceladus’ tiger stripes come from underground ocean

9:58 am

The uncertainty of science: Using a new computer model, scientists now think they have shown how on the Saturn moon Enceladus pressure from an underground ocean can push through cracks to produce geysers on the surface.

Rudolph and his colleagues ran a physics-based model to map the conditions that could allow the cracks from the surface to reach the ocean and cause the eruptions. The model accounts for cycles of warming and cooling that last on the scale of a hundred million years, associated with changes in Enceladus’ orbit around Saturn. During each cycle, the ice shell undergoes a period of thinning and a period of thickening. The thickening happens through freezing at the base of the ice shell, which grows downward like the ice on a lake, Rudolph said.

The pressure exerted by this downward-expanding ice on the ocean below is one possible mechanism researchers have proposed to explain Enceladus’ geysers. As the outer ice shell cools and thickens, pressure increases on the ocean underneath because ice has more volume than water. The increasing pressure also generates stress in the ice, which could become pathways for fluid to reach the surface 20-30 kilometers away.

You can read the paper here.

Be warned: This is only a model. Moreover, its conclusions suggest that this mechanism will not work on Jupiter’s moon Europa, which has many planet-wide crack-like features that suggest (as yet unconfirmed) a bubbling up from below.

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Hubble data detects persistent water vapor on one of Europa’s hemispheres

1:30 pm

Using data from the Hubble Space Telescope spanning sixteen Earth years, scientists have detected the presence of water vapor on Europa, but strangely spread only across one of the moon’s hemispheres.

Previous observations of water vapor on Europa have been associated with plumes erupting through the ice, as photographed by Hubble in 2013. They are analogous to geysers on Earth, but extend more than 60 miles high. They produce transient blobs of water vapor in the moon’s atmosphere, which is only one-billionth the surface pressure of Earth’s atmosphere.

The new results, however, show similar amounts of water vapor spread over a larger area of Europa in Hubble observations spanning from 1999 to 2015. This suggests a long-term presence of a water vapor atmosphere only in Europa’s trailing hemisphere – that portion of the moon that is always opposite its direction of motion along its orbit. The cause of this asymmetry between the leading and trailing hemisphere is not fully understood.

First, it must be emphasized that the amounts of atmospheric water being discussed are tiny, so tiny that on Earth we might consider this a vacuum.

Second, that the water vapor is only seen on the trailing hemisphere suggests there is some sort of orbital influence involved, though what that influence is remains unknown.

Hopefully when Europa Clipper finally arrives in orbit around Jupiter in 2030, with a path that will fly past Europa fifty times, we will some clarity on these questions.

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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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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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Europa’s mysterious stained grooves

11:18 am

Europa's jumbled icepack
Click for full image.

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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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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NASA IG finds both Europa missions a mess

10:25 am

Our incompetent federal government: A report released today [pdf] by NASA’s inspector general has found that the management of the Europa Clipper orbiter and the later Europa lander missions, both mandated by Congress, are facing serious budget and schedule risks, despite being given more than three-quarters of a billion dollars more than requested.

Congress has taken a strong interest in the project and since fiscal year (FY) 2013 has appropriated about $2.04 billion to NASA for a Europa mission—$1.26 billion more than the Agency requested.

…Despite [this] robust early-stage funding, a series of significant developmental and personnel resource challenges place the Clipper’s current mission cost estimates and planned 2023 target launch at risk. In addition, although Congress directed NASA to use the SLS to launch the Clipper, it is unlikely to be available by the congressionally mandated 2023 date and therefore the Agency continues to maintain spacecraft capabilities to accommodate both the SLS and two commercial launch vehicles, the Delta IV Heavy and Falcon Heavy. [emphasis mine]

The lander meanwhile is in even worse shape, especially because its congressionally-mandated launch date on SLS in 2025 seems impossible.

It seems to me that this entire project could be the poster boy for the overall incompetence of our so-called “betters” in Washington, who in the past three decades have failed spectacularly in practically every major project they have undertaken. The project was mandated on NASA by Congress, led by former congressman John Culberson (R-Texas), who was then the chairman of the House subcommittee that was in charge of funding the agency. It was his pet project. Though the planetary science community were glad to have this mission, it was listed as their second priority in their 2011 decadal survey. Culberson made it first, and also made sure it got a lot of money, far more than NASA ever requested.

Despite this strong support, the inspector general has now found that the project is being badly mismanaged and faces budget overruns and scheduling problems. The scheduling problems partly result from the project’s bad management, but mostly because of Congress’s demand that the spacecraft fly on SLS. Our vaunted elected officials wanted to give that boondoggle (they own pet project) a mission, something it didn’t have, and Europa Clipper and Lander were therefore given that task.

The problem, as I have documented endlessly, is that SLS is woefully behind schedule. It appears it will likely not be ready for Europa Clipper’s launch window in 2023.

But hey, let’s give our federal government more responsibility and power! Let’s go socialist!

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Giant ice pinnacles on Europa

9:15 am

In a new paper scientists note that getting the congressionally mandated Europa Clipper safely to the surface of Jupiter’s moon might be threatened by the existence there of forests of giant five-story high ice pinnacles.

Probes have shown that Europa’s ice-bound surface is riven with fractures and ridges, and new work published today in Nature Geosciences suggests any robotic lander could face a nasty surprise, in the form of vast fields of ice spikes, each standing as tall as a semitruck is long.

Such spikes are created on Earth in the frigid tropical peaks of the Andes Mountains, where they are called “pentinentes,” for their resemblance to devout white-clad monks. First described by Charles Darwin, pentinentes are sculpted by the sun in frozen regions that experience no melt; instead, the fixed patterns of light cause the ice to directly vaporize, amplifying minute surface variations that result in small hills and shadowed hollows. These dark hollows absorb more sunlight than the bright peaks around them, vaporizing down further in a feedback loop.

This work is based on computer models, so it has a lot of uncertainty. It also appears to assume that these pentinentes will be widespread across Europa’s equatorial regions, something so unlikely I find it embarrassing that they even imply it. I guarantee Europa’s surface will be more varied than that. If they are designing Europa Clipper properly, it will go into orbit first to scout out the best landing site, and will be able to avoid such hazards.

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Radiation maps of Europa

10:08 am

By culling together data from Voyager 1 and the Galileo orbiter, scientists have created a radiation map of the surface of Europa.

Using data from Galileo’s flybys of Europa two decades ago and electron measurements from NASA’s Voyager 1 spacecraft, Nordheim and his team looked closely at the electrons blasting the moon’s surface. They found that the radiation doses vary by location. The harshest radiation is concentrated in zones around the equator, and the radiation lessens closer to the poles.

Mapped out, the harsh radiation zones appear as oval-shaped regions, connected at the narrow ends, that cover more than half of the moon.

…In his new paper, Nordheim didn’t stop with a two-dimensional map. He went deeper, gauging how far below the surface the radiation penetrates, and building 3D models of the most intense radiation on Europa. The results tell us how deep scientists need to dig or drill, during a potential future Europa lander mission, to find any biosignatures that might be preserved.

The answer varies, from 4 to 8 inches (10 to 20 centimeters) in the highest-radiation zones – down to less than 0.4 inches (1 centimeter) deep in regions of Europa at middle- and high-latitudes, toward the moon’s poles.

This model, which by the way probably has large margins of error, will be used as a guide by the Europa Clipper scientists now planning that orbiter’s mission.

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Europa water plume detected in old Galileo data

8:22 am

Using old Galileo data and new techniques of analysis scientists have uncovered a water plume on Europa that the spacecraft flew through in 1997.

Over the course of 5 minutes, spikes the spacecraft recorded with its magnetic and plasma sensors reflected the alterations that a veil of ejected water, from one or many vents, could cause in a region matching the telescope observations, they report today in Nature Astronomy. This indicates that a region of the moon potentially 1000 kilometers long could host such activity, though it is impossible to say whether this is a single plume or many, like the complex system of fractures and vents seen on Enceladus. Indeed, on its own, this evidence was too weak to tie to erupting water in a 2001 study describing it, the authors add, but it fits well with the Hubble and modeled evidence.

As indicated by the quote above, the result has a lot of uncertainty.

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Water plumes on Europa plus hydrogen in Enceladus plumes

4:31 am

Scientists have detected more evidence of underground oceans on both Europa (orbiting Jupiter) and Enceladus (orbiting Saturn).

In the case of Europa, the Hubble Space Telescope has once again detected plumes of water ice being shot up from cracks in the moon’s surface. This second detection confirms the first from two years ago.

In the case of Enceladus, Cassini data has detected the presence of hydrogen in the plumes totaling 1% of the total material in the plumes.

The Europa story is significant, in that it confirms that the moon is still active geologically, and that the underground ocean is interacting with the outside world by ejecting material from it to the surface. This increases the odds that there will be some very intriguing chemistry in that ocean, including the possibility of organic life.

The Enceladus story puzzles me. We already know that the plumes there are made of water, which in itself is one third hydrogen. Why should anyone be surprised that a portion of that water gets split so that some of the hydrogen gets released as an atom instead of part of the water molecule. In fact, this discovery does not seem to me to be much of a discovery at all, but simply a confirmation that the plumes have the materials from the water ocean below the surface. That NASA has pushed it this week so hard in conjunction with their future Europa Clipper mission suggests that this part of the press story is really about lobbying for funds and has little to do with science.

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Water plumes on Europa?

11:40 am

New data from the Hubble Space Telescope suggests that there might be active water plumes issuing from Europa that are fed by the planet’s underground ocean.

In 10 separate occurrences spanning 15 months, the team observed Europa passing in front of Jupiter. They saw what could be plumes erupting on three of these occasions.

This work provides supporting evidence for water plumes on Europa. In 2012, a team led by Lorenz Roth of the Southwest Research Institute in San Antonio, detected evidence of water vapor erupting from the frigid south polar region of Europa and reaching more than 100 miles (160 kilometers) into space. Although both teams used Hubble’s Space Telescope Imaging Spectrograph instrument, each used a totally independent method to arrive at the same conclusion.

These results are very very uncertain. As the lead scientist noted twice during the press conference, the data is at the very limits of Hubble’s capabilities. I would not be surprised at all if later observations find that it is in error.

In fact, the press conference itself was more a PR event to lobby for Hubble as well as the James Webb Space Telescope than it was a description of a new discovery. The discovery itself was given a much bigger tease than it really deserves, considering the very uncertain nature of its data. I am a big fan of Hubble, as anyone who has read anything I have written in the past two decades. Nonetheless, I find this blatant lobbying very annoying. Also very annoying will be the naive willingness of many in the press to buy into this story. Expect a lot of silly stories today and tomorrow screaming that water jets coming from Europa have been definitely photographed by Hubble.

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Congress pushes for Europa missions

9:14 am

A new House budget bill stipulates that NASA fly two unmanned missions to Europa, including a lander, and do it soon.

The bill also includes several hundred million per year for the missions, at least at the beginning. Even though planetary scientists have recommended that NASA do at least one mission to Eurpoa relatively soon, it appears that these missions are the particular pet projects of the committee chairman in Congress.

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