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Lucy in the Sky with Donaldjohanson:The girl with Anti-Collide-o-scope eyes
#1
NSFV
(Not Safe for Vianova.)

Hi Fly Hi bye  Hi  Palooza!  Arrow


[Image: jupiter_trojans_fixed_point-slower.gif?itok=3dKrfm3p]

"The girl with Anti-Collide-o-scope eyes"

[Image: 45703172644_f1687fde12_b.jpg]
Quote:"OpNav," as optical navigation technical lead Coralie Adam refers to it, is the usage of imagery from the on-board cameras to determine Lucy's position relative to the target. This is a useful measurement used by the navigation team to tweak Lucy's route and ensure it stays on the nominal flyby path. Adam works in Simi Valley, California, with KinetX, the company NASA selected to conduct Lucy's deep space navigation.





Navigating NASA's first mission to the Trojan asteroids
December 21, 2018, NASA

[Image: navigatingna.jpg]
This diagram illustrates Lucy's orbital path. The spacecraft’s path (green) is shown in a frame of reference where Jupiter remains stationary, giving the trajectory its pretzel-like shape. After launch in October 2021, Lucy has two close Earth flybys before encountering its Trojan targets. In the L4 cloud Lucy will fly by (3548) Eurybates (white), (15094) Polymele (pink), (11351) Leucus (red), and (21900) Orus (red) from 2027-2028. After diving past Earth again Lucy will visit the L5 cloud and encounter the (617) Patroclus-Menoetius binary (pink) in 2033. As a bonus, in 2025 on the way to the L4, Lucy flies by a small Main Belt asteroid, (52246) Donaldjohanson (white), named for the discoverer of the Lucy fossil.Lucy in the Sky with Donaldjohanson: After flying by the Patroclus-Menoetius binary in 2033, Lucy will continue cycling between the two Trojan clouds every six years. Credit: Southwest Research Institute
In science fiction, explorers can hop in futuristic spaceships and traverse half the galaxy in the blink of a plot hole. However, this sidelines the navigational acrobatics required in order to guarantee real-life mission success.




In 2021, the feat of navigation that is the Lucy mission will launch. To steer Lucy towards its targets doesn't simply involve programming a map into a spacecraft and giving it gas money – it will fly by six asteroid targets, each in different orbits, over the course of 12 years.

Lucy's destination is among Jupiter's Trojan asteroids, clusters of rocky bodies almost as old as the Sun itself, and visiting these asteroids may help unlock the secrets of the early solar system. Lucy will encounter a Main Belt asteroid in 2025, where it will conduct a practice run of its instruments before encountering the first four Trojan targets from 2027-2028. In 2033, Lucy will end its mission with a study of a binary system of two Trojans orbiting each other.

Getting the spacecraft where it needs to go is a massive challenge. The solar system is in constant motion, and gravitational forces will pull on Lucy at all times, especially from the targets it aims to visit. Previous missions have flown by and even orbited multiple targets, but none so many as will Lucy.

Scientists and engineers involved with trajectory design have the responsibility of figuring out that route, under Flight Dynamics Team Leader Kevin Berry of NASA's Goddard Space Flight Center in Greenbelt, Maryland. One such engineer is Jacob Englander, the optimization technical lead for the Lucy mission. "There are two ways to navigate a mission like Lucy," he said. "You can either burn an enormous amount of propellant and zig-zag your way around trying to find more targets, or you can look for an opportunity where they just all happen to line up perfectly." To visit these aligned targets, the majority of Lucy's high-speed lane changes will come from gravity assists, with minimal use of fueled tweaks.

Though Lucy is programmed to throw itself out into a celestial alignment that will not occur for decades, it cannot be left to its own devices. Once the spacecraft begins to approach its asteroid targets, optical navigation is the next required step.
[Image: jupiter_trojans-slower.gif?itok=Rf8C5S5S]
"OpNav," as optical navigation technical lead Coralie Adam refers to it, is the usage of imagery from the on-board cameras to determine Lucy's position relative to the target. This is a useful measurement used by the navigation team to tweak Lucy's route and ensure it stays on the nominal flyby path. Adam works in Simi Valley, California, with KinetX, the company NASA selected to conduct Lucy's deep space navigation.



By using the communications link from the spacecraft to Earth, Adam said, the Lucy team gets information about the spacecraft's location, direction and velocity. The spacecraft takes pictures and sends them down to Earth, where Adam and other optical navigators use software to determine where the picture was taken based on the location of stars and the target. The orbit determination team uses this data along with data from the communications link to solve for where the spacecraft is and where it is expected to be, relative to the Trojans. The team then designs a trajectory correction maneuver to get Lucy on track. "The first maneuver is tiny," said navigation technical lead Dale Stanbridge, who is also of KinetX. "But the second one is at 898 meters per second. That's a characteristic of Lucy: very large delta V maneuvers." Delta V refers to the change in speed during the maneuver.

Communicating all of these navigation commands with Lucy is a process all on its own. "Lockheed Martin sends the commands to the spacecraft via the Deep Space Network," Adam said. "What we do is we work with Lockheed and the Southwest Research Institute, where teams are sequencing the instruments and designing how the spacecraft is pointed, to make sure Lucy takes the pictures we want when we want them."

"The maneuvers to correct Lucy's trajectory are all going to be really critical because the spacecraft must encounter the Trojan at the intersection of the spacecraft and Trojan orbital planes," Stanbridge said. "Changing the spacecraft orbital plane requires a lot of energy, so the maneuvers need to be executed at the optimal time to reach to next body while minimizing the fuel cost."

While Lucy is conducting deep space maneuvers to correct its trajectory toward its targets, communications with the spacecraft are sometimes lost for brief periods. "Blackout periods can be up to 30 minutes for some of our bigger maneuvers," Stanbridge said. "Other times you could lose communications would be when, for example, the Sun, comes between the Earth tracking station and the spacecraft, where the signal would be degraded by passing through the solar plasma."

Losing contact isn't disastrous, though. "We have high-fidelity predictions of the spacecraft trajectory which are easily good enough to resume tracking the spacecraft when the event causing a communication loss is over," Stanbridge said.

What route will Lucy take once its mission is complete, nearly 15 years from now? "We're just going to leave it out there," Englander said. "We did an analysis to see if it passively hits anything, and looking far into the future, it doesn't." The Lucy team has given the spacecraft a clear path for thousands of years, long after Lucy has rewritten the textbooks on our solar system's history.

Explore further: NASA's mission to Jupiter's Trojans given the green light for development

More information: For more information about NASA's Lucy mission, visit: www.nasa.gov/lucy 

Provided by: NASA


Read more at: https://phys.org/news/2018-12-nasa-missi...s.html#jCp


Lucy in the Sky with Diamonds  Holycowsmile 15 years of fly-byes from now.


[Image: 994ada48e9e34733f9590d7cfc309a77.gif]
https://www.nasa.gov/content/goddard/luc...rs-trojans
What a trip!
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#2
Quote: visiting these asteroids may help unlock the secrets of the early solar system.

If we are learning so much about our "secrets" of the Early Solar system, why are scientists still fracking so far off on dating things?

Why aren't we landing in Cydonia if you REALLY REALLY wanted to find about something UNKNOWN...

GO WHERE YOU ALREADY KNOW YOU DON'T KNOW !!!   Doh


I swear we spend more $$$ and Time staying AWAY from Cydonia than just LANDING there and say hello we got here and guess what...it really is a FACE !!!

Bob... Ninja Assimilated
"The Morning Light, No sensation to compare to this, suspended animation, state of bliss, I keep my eyes on the circling sky, tongue tied and twisted just and Earth Bound Martian I" Learning to Fly Pink Floyd [Video: https://vimeo.com/144891474]
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#3
ULA wins contract to launch NASA’s Lucy mission to visit unexplored asteroids
February 1, 2019 Stephen Clark


Donaldjohanson Flyby: April 20, 2025


[Image: 38851455840_6ea0304002_k.jpg][img=788x0]https://mk0spaceflightnoa02a.kinstacdn.com/wp-content/uploads/2019/02/38851455840_6ea0304002_k.jpg[/img]File photo of a United Launch Alliance Atlas 5-401 rocket lifting off from Cape Canaveral. Credit: United Launch Alliance
NASA has selected United Launch Alliance’s Atlas 5 rocket to dispatch the Lucy spacecraft on a mission from Cape Canaveral in October 2021 to fly by seven unexplored asteroids, including six objects locked in orbits leading and trailing Jupiter, where scientists expect swarms of miniature worlds could hold clues about the formation of the solar system.

The space agency announced the contract award to ULA on Thursday, extending the company’s history of launching prominent interplanetary missions, a list that includes still-operating probes such as the InSight and Curiosity landers to Mars, the Juno spacecraft orbiting Jupiter, New Horizons in the Kuiper Belt, and the OSIRIS-REx asteroid sample return mission.
Built by Lockheed Martin, the Lucy spacecraft will lift off aboard an Atlas 5 rocket with a four-meter (13-foot) diameter payload shroud and no solid rocket boosters, a variant known as the “401” configuration. The launch will occur at ULA’s Complex 41 launch pad at Cape Canaveral.
“We could not be more pleased that NASA has selected ULA to launch this amazing planetary science mission,” said Tory Bruno, ULA’s president and chief executive officer. “This mission has a once-in-a-lifetime planetary launch window, and Atlas 5’s world-leading schedule certainty, coupled with our reliability and performance provided the optimal vehicle for this mission.”
The launch window for the Lucy mission opens Oct. 16, 2021, and extends several weeks. If the launch is delayed beyond the 2021 launch window, a backup opportunity is available approximately one year later, according to Simone Marchi, Lucy’s deputy project scientist from the Southwest Research Institute.
“Our Atlas 5 rocket has launched 79 times achieving 100 percent mission success, and we look forward to working again with our mission partners to explore our universe,” Bruno said in a statement.
The launch contract is valued at $148.3 million, a figure that includes the launch service and other mission-related costs, according to NASA.
ULA said NASA selected the Atlas 5 rocket after a “competitive launch service task order evaluation” by the space agency’s Launch Services Program. ULA’s Atlas 5 and Delta 4 rockets are certified to launch NASA’s robotic interplanetary science missions, alongside SpaceX’s Falcon 9 launcher. Both companies are expected to submit bids for each task order competition managed the Launch Services Program.
After launching aboard the Atlas 5 rocket, Lucy will a combination of on-board thrusters and three gravity assist flybys with Earth to spiral into an elongated orbit around the sun, first to encounter a main-belt asteroid between the orbits of Mars and Jupiter in 2025, then to explore six objects farther out in the solar system five times farther from the sun than the Earth.
Lucy will be the first mission to visit a class of solar system objects known as the Trojan asteroids, which orbit in tandem with Jupiter, with groups ahead of and behind the giant planet in its path around the sun.
[Image: 1000days.jpg][img=788x0]https://mk0spaceflightnoa02a.kinstacdn.com/wp-content/uploads/2019/02/1000days.jpg[/img]Artist’s concept of the Lucy spacecraft flying by Trojan asteroids. Credit: NASA/SWRI
Scientists believe the Trojan asteroids represent a diverse sample of the types of small planetary building blocks that populated the solar system after its formation 4.5 billion years ago.
“If there’s anything we’ve learned in the last 30 years, it’s the planets like Earth do not form, excuse the pun, in a vacuum,” said Hal Levison, Lucy’s principal investigator from the Southwest Research Institute in Boulder. “They form as a result of a complex interaction of various regions of the solar system handing material back and forth as the planets accreted. As a result, to understand where a planet like the Earth comes from, you really have to understand the system as a whole.”
That’s why NASA has launched, or is developing, nearly a dozen robotic missions to explore asteroids, comets and objects in the distant Kuiper Belt — all in the last 25 years. Thomas Zurbuchen, head of NASA’s science directorate, said the space agency is investing between $5 billion and $6 billion in missions to small bodies in the current decade.
“The reason why these (objects) are particularly interesting is because they are sculpted by the formation of the planetary system, and most of the material in it has remained roughly unchanged since the beginning of the solar system, and that’s why NASA has put so much effort into trying to understand these bodies,” Levison said.
“Lucy will launch in just about 1,000 days, which is a little intimidating to me,” Levison said. “We’re going to have a main-belt asteroid rehearsal in 2025, and five Trojan encounters going between 2027 and 2033, for a total of six objects because one of the objects we’re studying is going to be a binary, which is, I must admit, my favorite.”
Initially thought to be the remnant leftovers from the formation of Jupiter, the Trojan asteroids actually appear different from one another, with some appearing reddish in color, and others have a dark charcoal-like color.
Levison co-authored the Nice model, which suggests the solar system’s four giant planets — Jupiter, Saturn, Uranus and Neptune — all formed relatively close together, with a disk of dust and rocks extending farther from the sun.
“The Nice model predicts that this planetary system was unstable,” Levison said. “The orbits went basically nuts. Uranus and Neptune gravitationally scattered off one another and were thrown out into this disk of material by Jupiter and Saturn. The disk went kablooey because of the gravitational effects of the planets, and … most of the material was thrown out into interstellar space, but you have a small population right about Jupiter, which represents the Trojans.
“This is just a theory, but if this is all true, then the Trojan population represents objects that formed throughout that disk (in the early solar system), so it’s an opportunity for us to understand that disk by just going to the small region that we call the Trojans,” he said.
“In order to take advantage of this diversity, we need to be able to cover a lot of real estate, and study a lot of these objects,” Levison said.
After Lucy’s launch, the spacecraft will return to fly by Earth on Oct. 16, 2022, and Dec. 13, 2024, to use the planet’s gravity to slingshot farther from the sun.
[Image: trojans_nolabels-2.gif][img=500x0]https://mk0spaceflightnoa02a.kinstacdn.com/wp-content/uploads/2019/02/trojans_nolabels-2.gif[/img]During the course of its mission, Lucy will fly by six Jupiter Trojans. This time-lapsed animation shows the movements of the inner planets (Mercury, brown; Venus, white; Earth, blue; Mars, red), Jupiter (orange), and the two Trojan swarms (green) during the course of the Lucy mission. Credit: Astronomical Institute of CAS/Petr Scheirich
The probe will encounter its first extraterrestrial target on April 20, 2025, when it speeds by the 2.4-mile-wide (3.9-kilometer) asteroid Donaldjohanson, named for the paleoanthropologist who discovered the fossil of Lucy, a human ancestor whose partial skeleton was discovered in Ethiopia in 1974.
“Lucy is named after the human ancestor fossil because these objects really represent the fossils of planet formation, so in honor of that, we named this asteroid Donald Johanson, the discoverer of Lucy,” Levison said.
Lucy will fly by four objects in one of the Trojan swarms over a 15-month period from August 2027 through November 2028, then return back to Earth for another gravity assist flyby on Dec. 26, 2030, to bend the spacecraft’s trajectory to aim for a binary pair of Trojan asteroids — named Patroclus and Menoetius — on March 2, 2033.
“This is a flyby mission,” Levison said. “We’re going to just about everything that we can do during a flyby. We’re going to look at surface geology, we’re going to get colors, we’re going to get compositions, we’re going to be able to measure the mass of these objects as we fly by using the Doppler shift, and we’re going to look for satellites and rings.”
Lucy’s four major science instruments — largely based on hardware flown on previous interplanetary missions — will be mounted to an articulating platform at the top of the spacecraft, which stands around 15 feet (5 meters) tall and has two fan-shaped UltraFlex solar array wings built by Northrop Grumman Innovation Systems, formerly known as Orbital ATK. Lucy’s chemical propulsion system will be fueled by hydrazine for major in-space maneuvers.
NASA selected Lucy in 2017 from 28 proposals submitted by U.S. science teams as part of the Discovery line of cost-capped planetary probes, a program under which the agency’s Mars Pathfinder rover, the Messenger mission to orbit Mercury, the Dawn spacecraft that visited Vesta and Ceres in the asteroid belt, and the InSight lander currently on Mars were developed, built and launched.
[Image: PM-HST-20180213-median.png][img=788x0]https://mk0spaceflightnoa02a.kinstacdn.com/wp-content/uploads/2019/02/PM-HST-20180213-median.png[/img]The Hubble Space Telescope captured this view of the Patroclus-Menoetius binary pair in February 2018. Credit: SWRI
In addition to Lucy, NASA selected the Psyche mission to explore a unique asteroid made almost entirely of iron-nickel metal. Psyche will launch in August 2022 and reach its destination in January 2026.
The Lucy and Psyche missions costs to NASA are capped at $450 million each, excluding launch costs.
Here is a preliminary timeline of Lucy’s mission:
  • Launch: Oct. 16, 2021

  • Deep Space Maneuver 1: Nov. 15, 2021

  • Earth Flyby 1: Oct. 16, 2022

  • Deep Space Maneuver 2: Feb. 2, 2024

  • Earth Flyby 2: Dec. 13, 2024

  • Donaldjohanson Flyby: April 20, 2025

  • Deep Space Maneuver 3: April 3, 2027

  • Eurybates Flyby: Aug. 12, 2027

  • Polymele Flyby: Sept. 15, 2027

  • Deep Space Maneuver 4: Sept. 29, 2027

  • Leucus Flyby: April 28, 2028

  • Orus Flyby: Nov. 11, 2028

  • Earth Flyby 3: Dec. 26, 2030

  • Patroclus/Menoetius Flyby: March 2, 2033
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#4
...
Great  title for the thread!


Quote:“The orbits went basically nuts. 
Uranus and Neptune gravitationally scattered off one another
 and were thrown out into this disk of material by Jupiter and Saturn. 

The disk went kablooey  Rofl
because 
of the gravitational effects of the planets, 
and … most of the material was thrown out into interstellar space Nonono
but you have a small population right about Jupiter,
which represents the Trojans.


“This is just a theory  Naughty  
but 
if this is all true  Doh

then the Trojan population represents objects that formed throughout that disk 
(in the early solar system), 
so it’s an opportunity for us to understand that disk 
by just going to the small region that we call the Trojans,” he said.


Toilet  Tp  talky talk when the scientists theories can't walk a straight line,
or come up with something better than ... kablooey Whip 

I never agreed with these hazy and lazy models of ping pong gravity in planetary lala-paloooza.

But still, the mission will see a lot of interesting material.

What kind of distance imaging are they going to accomplish?
Do we get any guarantee of competent images with any detail?
Don't count on it.

...
Reply
#5
OCTOBER 21, 2019
Lucy mission completes critical design review
The Lucy mission led by Southwest Research Institute is one step closer to its 2021 launch to explore the Trojan asteroids, a population of ancient small bodies that share an orbit with Jupiter. With the successful completion of its critical design review last week, the Lucy spacecraft is on track to begin a 12-year journey of almost 4 billion miles to visit a record-breaking seven asteroids—one main belt asteroid and six Trojans.

"The Trojan asteroids are leftovers from the early days of our solar system, effectively fossils of the planet formation process," said SwRI's Harold Levison, the principal investigator of the mission. "They hold vital clues to deciphering the history of our solar system. Lucy, like the human ancestor fossil for which it is named, will revolutionize the understanding of our origins."
The design review was a major mission milestone. An independent board including members from NASA and several external organizations evaluated all aspects of the Lucy mission, from the spacecraft and instrument payload to flight hardware and software, systems engineering, mission assurance, ground systems and overall science mission. This marks the end of Lucy's design phase and a shift to building the spacecraft and instruments that will explore the diverse Trojan asteroids.
"Lucy's ability to fly by so many targets means that we will not only get the first up-close look at this unexplored population, but we will also be able to study why the asteroids appear so different," said SwRI's Cathy Olkin, deputy principal investigator of the mission. "The mission will provide an unparalleled glimpse into the formation of our solar system, helping us understand the source of volatiles and organics on the terrestrial planets and the evolution of the planetary system as a whole."

Now that the Lucy mission has passed its critical design review, construction will begin in earnest. While Lockheed Martin is building the spacecraft, the Goddard Space Flight Center, the Johns Hopkins University Applied Physics Laboratory and Arizona State University will build a suite of complementary imaging and mapping instruments to remotely probe this enigmatic population of asteroids.
"The Lucy team has been working for over a year reviewing the designs of every system and subsystem," said Goddard's Donya Douglas-Bradshaw, Lucy's project manager. "Through all this hard work, the team is doing everything possible to ensure a successful mission. The team is to be commended for their dedication."
SwRI is the principal investigator institution and will lead the science investigation. Goddard will provide overall mission management, systems engineering, and safety and mission assurance.




Explore further
NASA's mission to Jupiter's Trojans given the green light for development



Provided by Southwest Research Institute

https://phys.org/news/2019-10-lucy-missi...tical.html
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#6
OCTOBER 24, 2019
Beyond Jupiter, researchers discover a 'cradle of comets'
by Daniel Stolte, University of Arizona
[Image: beyondjupite.jpg]A comet worthy of worship: An artist illustration of what centaur SW1 would look like if it became an inner solar system Jupiter-Family comet at a distance of 0.2 AU (19 million miles) from Earth. The moon is in the upper right part of the frame for scale. Credit: Heather Roper
Comets are known to have a temper. As they swoop in from the outer edges of our solar system, these icy bodies begin spewing gas and dust as they venture closer to the sun. Their luminous outbursts can result in spectacular sights that grace the night sky for days, weeks or even months.

But comets aren't born that way, and their pathway from their original formation location toward the inner solar system has been debated for a long time. Comets are of great interest to planetary scientists because they are likely to be the most pristine remnants of material left over from the birth of our solar system.
In a study published in the Astrophysical Journal Letters, a team of researchers including Kathryn Volk and Walter Harris at the University of Arizona Lunar and Planetary Laboratory report the discovery of an orbital region just beyond Jupiter that acts as a "comet gateway." This pathway funnels icy bodies called centaurs from the region of the giant planets—Jupiter, Saturn, Uranus and Neptune—into the inner solar system, where they can become regular visitors of Earth's neighborhood, cosmically speaking.
Roughly shaped like an imaginary donut encircling the area, the gateway was uncovered as part of a simulation of centaurs, small icy bodies traveling on chaotic orbits between Jupiter and Neptune.
[b]Centaurs: Icy Rogues on Haphazard Trails[/b]
Centaurs are believed to originate in the Kuiper belt, a region populated by icy objects beyond Neptune and extending out to about 50 Astronomical Units, or 50 times the average distance between the sun and the Earth. Close encounters with Neptune nudge some of them onto inward trajectories, and they become centaurs, which act as the source population of the roughly 1,000 short-period comets that zip around the inner solar system. These comets, also known as Jupiter-family comets, or JFCs, include comets visited by spacecraft missions such as Tempel 1 (Deep Impact), Wild 2 (Stardust) and 67P/Churyumov-Gerasimenko (Rosetta).
"The chaotic nature of their orbits obscures the exact pathways these centaurs follow on their way to becoming JFCs," said Volk, a co-author on the paper and an associate staff scientist who studies Kuiper belt objects, planetary dynamics and planets outside our solar system. "This makes it difficult to figure out where exactly they came from and where they might go in the future."

Jostled by the gravitational fields of several nearby giant planets—Jupiter, Saturn and Neptune—centaurs don't tend to stick around, making for a high-turnover neighborhood, Harris said.
"They rattle around for a few million years, perhaps a few tens of millions of years, but none of them were there even close to the time when the solar system formed," he said.
"We know of 300 centaurs that we can see through telescopes, but that's only the tip of an iceberg of an estimated 10 million such objects," Harris added.
"Most centaurs we know of weren't discovered until CCD's became available, plus you need the help of a computer to search for these objects," Volk said. "But there is a large bias in observations because the small objects simply aren't bright enough to be detected."
[b]Where Comets Go to Die[/b]
Every pass around the sun inflicts more wear and tear on a comet until it eventually breaks apart, has a close encounter with a planet that ejects it from the inner solar system, or its volatiles—mostly gas and water—are depleted.
"Often, much of the dust remains and coats the surface, so the comet doesn't heat up much anymore and it goes dormant," Harris said.
By some mechanism, a steady supply of "baby comets" must replace those that have run their course, "but until now, we didn't know where they were coming from," he added.
To better understand how centaurs become JFCs, the research team focused on creating computer simulations that could reproduce the orbit of 29P/Schwassmann-Wachmann 1, or SW1, a centaur discovered in 1927 and thought to be about 40 miles across.

[Image: 1-beyondjupite.jpg]
Comet 29P/Schwassmann-Wachmann as seen by NASA's Spitzer Space Telescope. Credit: NASA
SW1 has long puzzled astronomers with its high activity and frequent explosive outbursts despite the fact that is too far from the sun for water ice to melt. Both its orbit and activity put SW1 in an evolutionary middle ground between the other centaurs and the JFCs, and the original goal of the investigation was to explore whether SW1's current circumstances were consistent with the orbital progression of the other centaurs.
To accomplish this, the team modeled the evolution of bodies from beyond Neptune's orbit, through the giant planet's region and inside Jupiter's orbit.
"The results of our simulation included several findings that fundamentally alter our understanding of comet evolution," Harris said. "Of the new centaurs tracked by the simulation, more than one in five were found to enter an orbit similar to that of SW1 at some point in their evolution."
In other words, even though SW1 appears to be the only large centaur of the handful of objects currently known to occupy the "cradle of comets," it is not the outlier it was thought to be, but rather ordinary for a centaur, according to Harris.
In addition to the commonplace nature of SW1's orbit, the simulations led to an even more surprising discovery.
"Centaurs passing through this region are the source of more than two-thirds of all Jupiter-family comets," Harris said, "making this the primary gateway through which these comets are produced."
"Historically, our assumption has been that the region around Jupiter is fairly empty, cleaned out by the giant planet's gravity, but our results teach us that there is a region that is constantly being fed," Volk says.
This constant source of new objects may help explain the surprising rate of icy body impacts with Jupiter, such as the famous Shoemaker-Levy 9 event in 1994.
[b]A Comet Worthy of Worship[/b]
Based on estimates and calculations of the number and size of objects entering, inhabiting and leaving the gateway region, the study predicted it should sustain an average population of about 1,000 Jupiter-family objects, not too far off the 500 that astronomers have found so far.
The results also showed that the gateway region triggers a rapid transition: once a centaur has entered it, it is very likely to become a JFC within a few thousand years, a blink of an eye in solar system timeframes.
The calculations suggest that an object of SW1's size should enter the region every 50,000 years, making it likely that SW1 is the largest centaur to begin this transition in all of recorded human history, Harris and Volk suggest. In fact, SW1 could be on its way to becoming a "super comet" within a few thousand years.
Comparable in size and activity to comet Hale-Bopp, one of the brightest comets of the 20th century, SW1 has a 70% chance of becoming what could potentially amount to the most spectacular comet humankind has ever seen, the authors suggest.
"Our descendants could be seeing a comet 10 to 100 times more active than the famous Halley comet," Harris said, "except SW1 would be returning every six to 10 years instead of every 75."
"If there had been a comet this bright in the last 10,000 years we would know about it," Volk said.
"We take this as strong evidence that a similar event has not happened at least since then," Harris said, "because ancient civilizations would not only have recorded the comet, they may have worshiped it!"




Explore further
Comet gateway discovered to inner solar system, may alter fundamental understanding of comet evolution



[b]More information:[/b] G. Sarid et al. 29P/Schwassmann–Wachmann 1, A Centaur in the Gateway to the Jupiter-family Comets, The Astrophysical Journal (2019). DOI: 10.3847/2041-8213/ab3fb3
[b]Journal information:[/b] Astrophysical Journal Letters  Astrophysical Journal [/url]

Provided by [url=https://phys.org/partners/university-of-arizona/]University of Arizona

https://phys.org/news/2019-10-jupiter-cr...omets.html
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#7
...
I think they are on to something but I still lack confidence in their assertions


Quote:The calculations suggest that an object of SW1's size 
should enter the region every 50,000 years Nonono
making it likely that SW1 
is the largest centaur to begin this transition in all of recorded human history ...


No and no.
"recorded human history" is about 5 % unearthed.


Quote:"We know of 300 centaurs that we can see through telescopes, 
but that's only the tip of an iceberg,
of an estimated 10 million such objects," Harris added.


10 million is a guess.
what is out there in the Kuiper belt is likely underestimated as well.



Quote:"The results of our simulation Whip
included several findings,
that fundamentally alter our understanding of comet evolution,"


They will be saying the exact same thing in a few years with their updated models and simulations.

lack of quality data, but it gets better all the time.
...
Reply
#8
There was a story out here by EA that the Milky Way got invaded way way back when scientists were still using "maybe numbers of billions years" but the Flat Fact is that OUR Solar System does NOT come from the Milky Way Galaxy but likely part of the galaxy that slammed INTO the Milky Way many eon ago.

That's why we seem to be the ONLY Solar System moving around the outskirts on the Milky Way but going up then down the 'mean horizon' of he ORIGINAL Milky Way.

Because if OUR system was BORN in the Milky Way; it would NOT have that 24,000 year wobble as it spends 48,000 years going around the Milky Way.  So all these fly snot-balls out there NEAR US ... are likely have NOTHING and I mean zippo to the Nature of How the Milky Way got it's start.

Makes common sense to me ... Hmm2

Bob... Ninja Assimilated
"The Morning Light, No sensation to compare to this, suspended animation, state of bliss, I keep my eyes on the circling sky, tongue tied and twisted just and Earth Bound Martian I" Learning to Fly Pink Floyd [Video: https://vimeo.com/144891474]
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#9
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That is true about the dwarf galaxy being consumed by the Milky way in a collision.
It was shredded apart by the Milky Way,'
and our solar system was part of that galaxy.
It has a name in the scientific literature, but I forget it currently.

Slap2

here it is after all
Sagittarius Dwarf Galaxy --- home

http://viewzone.com/milkyway.html


Quote:scientists announced that the Sun, the Moon, our planet and its siblings, 
were not born into the familiar band of stars known as the Milky Way galaxy, 
but we actually belong to a strange formation Whip 
with the unfamiliar name of the Sagittarius Dwarf galaxy!

Using volumes of data from the Two-Micron All Sky Survey (2MASS), 
a major project to survey the sky in infrared light led by the University of Massachusetts, 
the astronomers are answering questions that have baffled scientists for decades,
 and proving that our own Milky Way is consuming one of its neighbors, 
in a dramatic display of ongoing galactic cannibalism. 

The study published in the Astrophysical Journal, 
is the first to map the full extent of the Sagittarius galaxy
 and show in visually vivid detail how its debris wraps around and passes through our Milky Way. 
Sagittarius is 10,000 times smaller in mass than the Milky Way, 
so it is getting stretched out, 
torn apart and gobbled up by the bigger Milky Way.

The fact that the Milky Way is seen in the sky at an angle has always puzzled astronomers. 
If we originated from the Milky Way, 
we ought to be oriented to the galaxy's ecliptic, 
with the planets aligned around our Sun in much the same angle as our Sun aligns with the Milky Way. 
Instead, as first suggested by researcher Matthew Perkins Erwin, 
the odd angle suggests that our Sun is influenced by some other system. 
Together with data from the Two-Micron All Sky Survey we now know what it is. 
We actually belong to the Sagittarius Dwarf galaxy.

By using infrared maps, 
the astronomers filtered away millions of foreground stars,
to focus on a type of star called an M giant. 

These large, infrared-bright stars are populous in the Sagittarius galaxy,
but uncommon in the outer Milky Way. 
The 2MASS infrared map of M giant stars analyzed by Majewski and collaborators
is the first to give a complete view,
of the Milky Way galaxy's meal of Sagittarius stars, 
now wrapping like a spaghetti noodle around the Milky Way. 

Prior to this work, astronomers had detected only a few scattered pieces of the disrupted Sagittarius dwarf. 
Even the existence of Sagittarius, 
except in the field of Astrology and horoscopes, 
was unknown until the heart of this nearest satellite galaxy of the Milky Way,
was discovered by a British team of astronomers in 1994.


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