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Mercury: ESA / JAXA bepi-columbo to heat debate @~333F
#1
https://nssdc.gsfc.nasa.gov/planetary/fa...itish.html
Quote:Mean Temperature (F)

333LilD

[Image: spectra_mercury.jpg?mw=600]

http://em01.powweb.com/sciencetoday/astr..._unit.html
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Mercury studies reveal an intriguing target for BepiColombo
September 19, 2018, Europlanet


[Image: mercurystudi.jpg]
BepiColombo approaching Mercury. Credit: ESA/ATG medialab, NASA/JPL
A month before the planned launch of the joint ESA-JAXA BepiColombo mission to Mercury, two new studies shed light on when the innermost planet formed and the puzzle of its chemical composition. The findings will be presented by Bastien Brugger and Thomas Ronnet at the European Planetary Science Congress (EPSC) 2018 in Berlin.



Mercury is the least-studied of the terrestrial planets and is something of an anomaly compared to Venus, Earth and Mars. It is very small, very dense, has an oversized molten core, and formed under chemical conditions that mean it contains much less oxidized material than its neighbouring planets.

Research by a team at the University of Aix Marseille suggests that two factors may help explain why Mercury is so strange. Firstly, the planet may have formed very early in the solar system's history from condensed vapour from planetesimals. Secondly, that there may be more iron within Mercury's mantle than might be suggested by measurements of the surface.

"We think that very early in the solar system, planetesimals in the innermost region of the solar system could have formed from reprocessed material that was vaporized due to the extreme temperature there and subsequently recondensed," said Ronnet. "In addition, we are able to rule out a scenario where Mercury formed from a pile-up of planetesimals coming from further out in the solar system since, in this case, Mercury would contain more oxidized material than we actually find."

[Image: 1-mercurystudi.jpg]
Interior of Mercury. Credit: Brugger/ University of Aix Marseille/NASA/JPL/JHU-APL
Early studies have suggested that Mercury is very rich in iron, and contains more sulphur than should be available in the material from which the bulk of the solar system formed. Since then, the MESSENGER mission has greatly improved our view of the bulk composition of Mercury.

Brugger ran computer simulations of Mercury's interior investigating core and mantle compositions and compared the results with gravity data gathered by the MESSENGER mission. The results suggest that Mercury has a dense mantle that may contain substantial amounts of iron.

"MESSENGER revealed very low abundances of silicate iron on the surface of Mercury, and this element would instead be present in metallic or sulphide phases. Our study suggests that iron abundances in the mantle could be higher than values measured on the surface," said Brugger. "With the launch of BepiColombo, we will have a whole new suite of instruments to continue the investigation of Mercury's unique properties, and try to better understand the structure and origin of the planet."

[Image: 2-mercurystudi.jpg]
False colour image of Mercury to enhance the chemical, mineralogical, and physical differences between the rocks that make up Mercury’s surface. Credit: NASA/JHU-APL/Carnegie Institution of Washington
BepiColombo is Europe's first mission to Mercury. It is a joint endeavour between ESA and the Japan Aerospace Exploration Agency, JAXA, and consists of two scientific orbiters: ESA's Mercury Planetary Orbiter and JAXA's Mercury Magnetospheric Orbiter. They will be carried on a seven year journey to the innermost planet by the Mercury Transfer Module, using a combination of ion propulsion and gravity assist flybys at Earth, Venus and Mercury. The mission will study all aspects of Mercury, building on the achievements of MESSENGER to provide the best understanding of the solar system's innermost planet to date.

  [/url]Explore further: [url=https://phys.org/news/2018-07-bepicolombo-mid-october.html]BepiColombo to target mid-October launch

Provided by: Europlanet


Read more at: https://phys.org/news/2018-09-mercury-re...o.html#jCp




Mercury and its depressions
September 19, 2018 by Alice Lucchetti, American Geophysical Union


[Image: mercuryandit.jpg]
One of the three craters, the Canova crater, hosting hollows analyzed in this work. Credit: NASA
One of the most surprising discoveries of the NASA's Messenger mission was the presence of unusual, bright, irregular and rimless flat-floored depressions on the surface of Mercury. These depressions, called hollows, are usually found on crater walls, rims, floors and central peaks.



Since the hollows appear fresh, they may be actively forming today through a mechanism that could involve the loss of volatile compounds, but understanding how the hollows formed is still a major challenge for scientists.

In a new study published in Journal of Geophysical Research: Planets, a journal of the American Geophysical Union, lead author Alice Lucchetti and her Italian team analyzed the nature of Mercury's hollows inside three different impact craters: Dominici, Canova and Velazquez. The new study focuses understanding the geomorphology and compositional mineralogy of the hollows through the use of multi-color images acquired from the Mercury Dual Imaging System, or MDIS, instrument.

"We performed detailed geological mapping of the craters hosting hollows, making use of high- resolution images, in order to fully characterize the geological framework where these features formed." Lucchetti said.

The researchers separated the craters' areas into different units characterized by their spectral behavior. Comparing the results coming from the geomorphological and spectral analysis, we revealed a strong correlation between the spectral units and those identified in high-resolution geological maps," Lucchetti said.

[Image: 1-mercuryandit.jpg]
Comparison between the geological map and the spectral analysis for Canova crater. Hollows are identified by a well-defined spectrum (cluster #9). Credit: Lucchetti et al.
The new research shows the hollows in all three craters show a similar, well-defined, visible spectrum. When this spectrum is compared with laboratory spectra, it is indicative of a mixture of different materials.

"We found that both sulfides and pyroxene presenting transitional elements are responsible for the hollows absorption presented in the spectra," Lucchetti said. "This provides new insights into the hollows' nature and composition, suggesting that hollows terrains are the expression of not only the remnant material coming from a process that involve devolatilization, but also of the bedrock-forming material in which the hollows formed."

This work is important to scientists' overall understanding of the hollows.

"We are already studying other regions of Mercury to understand if it is a common behavior of these features or if different terrains affect their formation in different ways," she said.

The hollows will also be one of the main targets of interest of the upcoming European Space Agency and Japan Aerospace Exploration Agency BepiColombo mission, which will be launched in mid-October.

[Image: 1x1.gif] Explore further: Evidence for active hollows formation on Mercury

More information: A. Lucchetti et al. Mercury Hollows as Remnants of Original Bedrock Materials and Devolatilization Processes: A Spectral Clustering and Geomorphological Analysis, Journal of Geophysical Research: Planets (2018). DOI: 10.1029/2018JE005722


Provided by: American Geophysical Union


Read more at: https://phys.org/news/2018-09-mercury-de...s.html#jCp
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
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#2
...
Intrigueing info and ideas on the clusters of "hollows" within the large craters of Mercury.
The sublink at the bottom has a nice large image,
from another crater.
the bright spots with shallow depressions are the "hollows".

A couple of them out in the flat crater plain have little mounds.
One is dead center in the image, the other is directly above it, to the right of three shallow hollows.
That one has a curious form,
almost like the mound swells up from below. Try at 400-500%
A third mound centered one directly below at the bottom.
Might be ejecta boulders from the central peak formations,
and perhaps those are full of "volatiles" in question.

they mentioned -- sulphides and pyroxenes -- in the spectra.
It sure would be dandy if they were specific on the pyroxene contents.

https://3c1703fe8d.site.internapcdn.net/...cefora.jpg
[Image: 3-evidencefora.jpg]

...
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#3
BepiColombo Launches This Weekend to Crack Mysteries of Mercury — and Beyond
By Meghan Bartels, Space.com Senior Writer | October 18, 2018 07:30am ET

Mercury is a tiny, shrinking greyish ball of metal, an unassuming neighbor that's easy to overlook — but don't laugh off the possibility that the little world could rewrite our understanding of our own solar system as well as those all around us.

Scientists haven't visited the innermost planet since 2015, but that will change with a mission launching this week: BepiColombo, a joint project between the European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA). BepiColombo will launch from Kourou, French Guiana, at 9:45 p.m. EDT Oct. 19 (0145 GMT Oct. 20) on an Ariane 5 rocket; you can watch the launch live at Space.com courtesy of ESA.
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The long gap in missions didn't occur because the planet is boring. "Mercury is a challenge in many aspects: to get there, to stay there, and then there are many, many open questions that need to be solved," Joe Zender, deputy project scientist at ESA for the BepiColombo mission, told Space.com. "It's a kind of mystery — maybe one of the last mysteries on the terrestrial planets." [Most Enduring Mysteries of Mercury]
The problem, you see, is that when scientists put together what they know about the whole solar system and build explanations for how it came to be that way, Mercury keeps messing them up. It's the black sheep of the planetary family, with a host of weird characteristics.
[img=553x0]https://img.purch.com/w/640/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzA4MC8xMzMvaTAyL0JlcGlDb2xvbWJvX3N0YWNrX2FydGljbGVfbW9iLmpwZz8xNTM5ODM1MDg4[/img]

The spacecraft of the BepiColombo mission stacked together and waiting to be placed on board the rocket currently scheduled to launch Oct. 19 (Oct. 20 GMT).
Credit: M. Pedoussaut/ESA
Take, for example, how incredibly dense it is, with a massive metallic core surrounded by a thin, rocky shell, like a planetary M&M. Ignore Mercury and the planets line up neatly, from least dense at the center to densest at the edge of the solar system. But that model leaves scientists wondering how a planet so dense could have formed so near the sun. (One idea is that a giant impact stole away most of the lighter material, but that's still just a hypothesis.)
So, scientists want more information about Mercury to feed into their models of how the solar system formed, in hopes of coming up with an explanation that can even account for its strange traits.
But it's not just about our solar system, since our neighborhood is also a stand-in for the hundreds of other planetary systems that scientists have identified over the past couple of decades. Early results suggest those neighborhoods may also often host an unusually dense planet nearest their stars, just like Mercury, making the puzzle still more important to solve.
"We're discovering more and more solar systems every day," Nancy Chabot, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory who worked on NASA's most recent mission to Mercury, told Space.com. "We're going to first look here, to understand how our own solar system formed, to interpret all of these around us."









 


BepiColombo to the rescue
Fortunately for stumped scientists, BepiColombo will be uniquely poised to uncover some of Mercury's deepest secrets. "BepiColombo has the instruments to now do intensive investigations of everything from the interior out to the exosphere," James Slavin told Space.com. Slavin, who was referring to the thin layer of gas surrounding the planet like an extremely wimpy atmosphere, studies magnetic fields at the University of Michigan and is co-investigator on one of BepiColombo's instruments."It's just going to be very exciting," Slavin said. "This is the stage of planetary research where we finally get definitive answers to all of the questions we generated on [NASA's] Mariner 10 [mission, which flew by the planet three times in the 1970s] and MESSENGER [(NASA's Mercury Surface, Space Environment, Geochemistry and Ranging mission)]."
BepiColombo, which cost almost $2 billion, according to Spaceflight Now, is made up of two separate spacecraft, the European Mercury Planetary Orbiter and the Japanese Mercury Magnetospheric Orbiter, nicknamed Mio. The two have been joined together in an arrangement that's 20 feet (6 meters) tall for the seven-year-long journey to Mercury; once they arrive, they'll part ways but continue to work in tandem for at least a year. [Photos of Mercury from NASA's Messenger Spacecraft]
Having two spacecraft at the tiny planet will allow scientists to take unprecedented measurements of Mercury's magnetic field by keeping one spacecraft inside that field's bubble and one outside of it. It's unusual enough for such a small planet with a seemingly solid core to have a magnetic field at all, and being so close to the sun means it's constantly bombarded by a heavy stream of charged particles in the solar wind.









 







Here on Earth, the interaction of solar wind and magnetic field causes space weather, which when particularly strong can cause power outages. But our magnetic field is much stronger, and the solar wind that reaches us is much weaker. "Now we can investigate another different case and an extreme case, with strong solar wind and weak magnetic field, in order to understand how it works," Go Murakami, JAXA's project scientist for BepiColombo, told Space.com.
But that's just one facet of BepiColombo's long to-do list. Other instruments will be studying the planet itself, from its surface to deep down into its core. Geological questions BepiColombo should help scientists tackle include its past volcanic activity and why the already-tiny planet is shrinking. As it carries out its studies, it will be building on MESSENGER's work in the 2010s.
Take, for example, small hollows dotting the planet's surface. "They were one of the examples of why we send spacecraft to places we haven't been before," Chabot said. "They were a totally new landform that was discovered when MESSENGER got into orbit."
[img=553x0]https://img.purch.com/w/640/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzA4MC8xMzQvaTAyL0JlcGlDb2xvbWJvX2FwcHJvYWNoaW5nX01lcmN1cnlfYXJ0aWNsZV9tb2IuanBnPzE1Mzk4MzUyNDg=[/img][Image: MTUzOTgzNTI0OA==]

An artist's depiction of the BepiColombo spacecraft nearing their target, Mercury.
Credit: ESA/ATG medialab/NASA/JPL
The current idea is that the hollows are caused by rock actively sublimating — jumping straight from solid to gas — on the surface, and that the process is still playing out today. "It seems like some sort of volatiles, something that was there and then gets exposed to Mercury's surface, which is hot and close to the sun," Chabot said. "But it's very arm-wavy, because we've only been at this since 2011."
And there's another, more poignant way BepiColombo may follow in MESSENGER's footsteps: by photographing the crater likely about 50 feet (16 meters) across created when the spacecraft, out of fuel 11 years after its launch, slammed into the planet. Now, that abrupt end could be the beginning of new science if scientists can get a good glimpse of the rubble that the impact carried to the surface. "We know exactly when it happened," Chabot said, which means they can study how that rock weathered.
There's just one catch for BepiColombo: It will take the spacecraft seven years to fall into orbit around Mercury. Along the way, the spacecraft will fly past Earth once, Venus twice and Mercury itself six times, in a complicated dance designed to avoid the massive pull of the sun.
"We still have a very long way in front of us," Zender said, "but we are all very excited that we start the long journey now."
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#4
...
back a few posts to this link

http://em01.powweb.com/sciencetoday/astr..._unit.html

he has the "orbital period" -- sidereal of planets Mercury and Mars dead wrong

he has Mercury - 87.66 -- NASA 87.969  days
he has Mars 686.68 -- NASA 686.98  days

the interesting number was when he set Mercury as 1 AU,
and then the Jupiter correlation at 13.3333333~

-------------------------

Mercury and Jupiter have a unique and important astronomical cycle, 
recognized in ancient astronomical accounting research.
See my latest work on the number 187 -- 
Think NASA Jupiter sidereal 4332.589 days with that number 187. 
The true Mercury sidereal is listed above.

...

on the hollows {see earlier image}


Quote:The current idea is that the hollows Whip
are caused by rock actively sublimating — jumping straight from solid to gas — 
on the surface, 
and that the process is still playing out today.


and 



Quote:suggesting that hollows terrains
are the expression of not only the remnant material coming from a process that involve devolatilization,
but also of the bedrock-forming material in which the hollows formed."



They mentioned earlier -- sulfides and pyroxenes -- vague and incomplete no doubt.
The Hollows are intrigueing indeed.

Unfortunate that it will take 7 years to position the craft into the proper orbit around Mercury.
long wait ...

...

...
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#5
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Ariane 5 launches two satellites on 7-year voyage to Mercury
October 20, 2018
A powerful European Ariane 5 rocket blasted off from French Guiana late Friday and boosted a pair of satellites into space for a seven-year plunge into the inner solar system, a voyage requiring seven planetary flybys to slow down enough in the sun’s gravitational clutches to slip into orbit around hellish Mercury.



See ya in 7 years. Arrow
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#6
BepiColombo now firing on all cylinders
December 5, 2018, European Space Agency

[Image: bepicolombon.jpg]
Credit: BepiColombo approaching Mercury spacecraft: ESA/ATG medialab; Mercury: NASA/JPL
BepiColombo, the joint ESA/JAXA spacecraft on a mission to Mercury, is now firing its thrusters for the first time in flight.




On Sunday, BepiColombo carried out the first successful manoeuver using two of its four electric propulsion thrusters. After more than a week of testing which saw each thruster individually and meticulously put through its paces, the intrepid explorer is now one step closer to reaching the innermost planet of the solar system.

BepiColombo left Earth on 20 October 2018, and after the first few critical days in space and the initial weeks of in-orbit commissioning, its Mercury Transfer Module (MTM) is now revving up the high-tech ion thrusters.

The most powerful and high-performance electric propulsion system ever flown, these electric blue thrusters had not been tested in space until now.

It is these glowing power-packs that will propel the two science orbiters – the Mercury Planetary Orbiter and Mercury Magnetospheric Orbiter – on the seven-year cruise to the least explored planet of the inner solar system.

"Electric propulsion technology is very novel and extremely delicate," explains Elsa Montagnon, Spacecraft Operations Manager for BepiColombo.



[Image: 1-bepicolombon.jpg]
Twin ion thrusters firing. Credit: QinetiQ"This means BepiColombo's four thrusters had to be thoroughly checked following the launch, by slowly turning each on, one by one, and closely monitoring their functioning and effect on the spacecraft."


Testing took place during a unique window, in which BepiColombo remained in continuous view of ground-based antennas and communications between the spacecraft and those controlling it could be constantly maintained.

This was the only chance to check in detail the functioning of this fundamental part of the spacecraft, as when routine firing begins in mid-December, the position of the spacecraft will mean its antennas will not be pointing at Earth, making it less visible to operators at mission control.

The first fire

On 20 November at 11:33 UTC (12:33 CET), the first of BepiColombo's thrusters entered Thrust Mode with a force of 75 mN (millinewtons). With this BepiColombo was firing in space for the very first time.

Three hours later, the newly awakened thruster was really put through its paces as commands from mission control directed it to go full throttle, ramping up to 125mN – equivalent to holding an AAA battery at sea level.

[Image: 2-bepicolombon.jpg]
BepiColombo images high-gain antenna. Credit: ESA/BepiColombo/MTM , CC BY-SA 3.0 IGO
This may not sound like much, but this thruster was now working at the maximum thrust planned to be used during the life of the mission.



Thrust mode was maintained for five hours before BepiColombo transitioned back to Normal Mode. The entire time, ESA's Malargüe antenna in Argentina was in communication with the now glowing blue spacecraft – the colour of the plasma generated by the thruster as it burned through the xenon propellant.

These steps were then repeated for each of the other three thrusters over the next days, having only a tiny effect on BepiColombo's overall trajectory.

The small effects that were observed allowed the Flight Dynamics team to assess the thruster performance in precise detail: analysis of the first two firings reveals that the spacecraft was performing within 2% of its expected value. Analysis of the last two firings is ongoing.

Twenty-two arcs to go

"To see the thrusters working for the first time in space was an exciting moment and a big relief. BepiColombo's seven year trip to Mercury will include 22 ion thrust arcs – and we absolutely need healthy and well performing thrusters for this long trip," explains Paolo Ferri, ESA's Head of Operations.




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Animation visualising BepiColombo’s journey to Mercury. Credit: European Space Agency"Each thruster burn arc will last for extended periods of up to two months, providing the same acceleration from less fuel compared to traditional, high-energy chemical burns that last for minutes or hours."


During each long-duration burn the engines do take eight hour pauses, once a week, to allow the ground to perform navigation measurements in quiet dynamic conditions.

The first routine electric propulsion thrust arc will begin in mid-December, steering BepiColombo on its interplanetary trajectory and optimising its orbit ahead of its swing-by of Earth in April 2020.

Travelling some nine billion kilometers in total, BepiColombo will take nine flybys at Earth, Venus and Mercury, looping around the Sun 18 times.

By late 2025 the transfer module's work will be done: it will separate, allowing the two science orbiters to be captured by Mercury's gravity, studying the planet and its environment, along with its interaction with the solar wind, from complementary orbits.

"We put our trust in the thrusters and they have not let us down. We are now on our way to Mercury with electro-mobility," concludes Günther Hasinger, ESA Director of Science.

"This brings us an important step closer to unlocking the secrets of the mysterious innermost planet and ultimately, the formation of our solar system."

[Image: 1x1.gif] Explore further: Electric blue thrusters propelling BepiColombo to Mercury

Provided by: European Space Agency


Read more at: https://phys.org/news/2018-12-bepicolombo-cylinders.html#jCp
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