Ceres

[ramonmercado]

In the tens of thousands of photos returned by NASA's Dawn spacecraft, the interior of Ceres isn't visible. But scientists have powerful data to study Ceres' inner structure: Dawn's own motion.

Since gravity dominates Dawn's orbit at Ceres, scientists can measure variations in Ceres' gravity by tracking subtle changes in the motion of the spacecraft. Using data from Dawn, scientists have mapped the variations in Ceres' gravity for the first time in a new study in the journal Nature, which provides clues to the dwarf planet's internal structure.

"The new data suggest that Ceres has a weak interior, and that water and other light materials partially separated from rock during a heating phase early in its history," said Ryan Park, the study's lead author and the supervisor of the solar system dynamics group at NASA's Jet Propulsion Laboratory, Pasadena, California.

Ceres' gravity field is measured by monitoring radio signals sent to Dawn, and then received back on Earth, by NASA's Deep Space Network. This network is a collection of large antennas at three locations around the globe that communicate with interplanetary spacecraft. Using these signals, scientists can measure the spacecraft's speed to a precision of 0.004 inches (0.1 millimeters) per second, and then calculate the details of the gravity field.

Ceres has a special property called "hydrostatic equilibrium," which was confirmed in this study. This means that Ceres' interior is weak enough that its shape is governed by how it rotates. Scientists reached this conclusion by comparing Ceres' gravity field to its shape. Ceres' hydrostatic equilibrium is one reason why astronomers classified the body as a dwarf planet in 2006. ...

http://phys.org/news/2016-08-ceres-gravity.html



Read more at: http://phys.org/news/2016-08-ceres-gravity.html#jCp

 

[Peripart]

Could We Colonize Ceres Like in SyFy's 'The Expanse'?

"The Expanse" features a highly-developed Ceres colony whose gravity comes from the whole asteroid spinning. Living on real-life Ceres would be more of a challenge, at least at first.
Credit: SyfyIn "The Expanse" on SyFy features a hollowed-out asteroid (and dwarf planet) populated by a core group of miners as well as a society of civilians. The asteroid spins, so the colonists all experience gravity.

I haven't seen the show, but I don't see how spinning could increase the gravity. Unless they live upside-down in caverns, so the near surface of the asteroid is beneath their feet? That would work, I guess, but only near the nominal equator.

 

[ramonmercado]

I haven't seen the show, but I don't see how spinning could increase the gravity. Unless they live upside-down in caverns, so the near surface of the asteroid is beneath their feet? That would work, I guess, but only near the nominal equator.

I haven't seen it yet but I presume they would live in a huge cylindrical habitat within Ceres.

 

[ramonmercado]

NASA's Dawn spacecraft has lost another orientation-maintaining reaction wheel, but the failure doesn't threaten the probe's continuing work at the dwarf planet Ceres, agency officials said.

The malfunction occurred on Sunday (April 23), as Dawn was preparing for a planned Saturday (April 29) observation of Ceres' mysterious Occator Crater from an "opposition" position. This geometry, in which the spacecraft will be directly between the crater and the sun, could reveal new insights about Occator and its intriguing bright spots, NASA officials said.

Dawn has now lost three of its four reaction wheels, but such failures haven't unduly affected the probe, which has been orbiting the 590-mile-wide (950 kilometers) Ceres since March 2015. (Before that, Dawn circled the protoplanet Vesta — the second-largest body in the asteroid belt, behind Ceres — from July 2011 through September 2012.) ...

http://www.space.com/36627-nasa-daw..._medium=social&utm_campaign=2016twitterdlvrit

 

[eburacum]

You couldn't spin Ceres to get gravity - it would only fall apart. The object is mostly made of ice- it would flow like a glacier and break into blobs. It isn't really feasible to put a rotating cylinder inside the object either - any friction or waste heat would melt the ice, placing the cylinder underwater and causing even more friction.

Personally I don't think we need to spin Ceres at all - it already has 1/36th of Earth's gravity, which would be enough to stop things flying away from the surface. People would have to adapt. In the Expanse it seems that Belters prefer low gravity anyway.

If you really need to have a zone of high gravity on Ceres you could put a rotating belt around the equator, which could rotate once every 42 minutes to give 0.3 gees of centrifugal gravity. Located outside the ice layer it then could radiate any waste heat into space.

 

[eburacum]

A better idea altogether would be to mine Ceres' material to extract all the available carbon, then build a series of rotating habitats using graphene or carbon nanotube for strength.
Here's a paper from NASA's T. L. McKendree, which discusses the design of such a cylinder. Ceres could supply enough carbon to build at least twelve of these, each with the internal surface area of Russia.
http://www.zyvex.com/nanotech/nano4/mckendreePaper.html

And here's an image (by me) of a similar cylinder near a gas giant. The dishes at each end are light collection arrays.

 

[Bigphoot2]

Dawn Finds Possible Ancient Ocean Remnants at Ceres

This animation shows dwarf planet Ceres as seen by NASA's Dawn. The map overlaid at right gives scientists hints about Ceres' internal structure from gravity measurements. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
› Full image and caption
Minerals containing water are widespread on Ceres, suggesting the dwarf planet may have had a global ocean in the past. What became of that ocean? Could Ceres still have liquid today? Two new studies from NASA's Dawn mission shed light on these questions.

The Dawn team found that Ceres' crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and that this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres' rigid surface crust, which could be the signature of residual liquid left over from the ocean, too.

"More and more, we are learning that Ceres is a complex, dynamic world that may have hosted a lot of liquid water in the past, and may still have some underground," said Julie Castillo-Rogez, Dawn project scientist and co-author of the studies, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

etc

https://www.jpl.nasa.gov/news/news.php?feature=6982

 

[ramonmercado]

Minerals containing water are widespread on Ceres, suggesting the dwarf planet may have had a global ocean in the past. What became of that ocean? Could Ceres still have liquid today? Two new studies from NASA's Dawn mission shed light on these questions.

The Dawn team found that Ceres' crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and that this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres' rigid surface crust, which could be the signature of residual liquid left over from the ocean, too.

"More and more, we are learning that Ceres is a complex, dynamic world that may have hosted a lot of liquid water in the past, and may still have some underground," said Julie Castillo-Rogez, Dawn project scientist and co-author of the studies, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

What's inside Ceres? Gravity will tell.

Landing on Ceres to investigate its interior would be technically challenging and would risk contaminating the dwarf planet. Instead, scientists use Dawn's observations in orbit to measure Ceres' gravity, in order to estimate its composition and interior structure.

https://phys.org/news/2017-10-dawn-ancient-ocean-remnants-ceres.html

 

[Bigphoot2]

Latest news about Ceres

Bright Areas on Ceres Suggest Geologic Activity

The bright areas of Occator Crater -- Cerealia Facula in the center and Vinalia Faculae to the side -- are examples of bright material found on crater floors on Ceres. This is a simulated perspective view. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
› Full image and caption
If you could fly aboard NASA's Dawn spacecraft, the surface of dwarf planet Ceres would generally look quite dark, but with notable exceptions. These exceptions are the hundreds of bright areas that stand out in images Dawn has returned. Now, scientists have a better sense of how these reflective areas formed and changed over time -- processes indicative of an active, evolving world.

"The mysterious bright spots on Ceres, which have captivated both the Dawn science team and the public, reveal evidence of Ceres' past subsurface ocean, and indicate that, far from being a dead world, Ceres is surprisingly active. Geological processes created these bright areas and may still be changing the face of Ceres today," said Carol Raymond, deputy principal investigator of the Dawn mission, based at NASA's Jet Propulsion Laboratory in Pasadena, California. Raymond and colleagues presented the latest results about the bright areas at the American Geophysical Union meeting in New Orleans on Tuesday, Dec. 12.

etc

https://www.jpl.nasa.gov/news/news.php?feature=7022

 

[ramonmercado]

Minerals containing water are widespread on Ceres, suggesting the dwarf planet may have had a global ocean in the past. What became of that ocean? Could Ceres still have liquid today? Two new studies from NASA's Dawn mission shed light on these questions.

The Dawn team found that Ceres' crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and that this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres' rigid surface crust, which could be the signature of residual liquid left over from the ocean, too.

"More and more, we are learning that Ceres is a complex, dynamic world that may have hosted a lot of liquid water in the past, and may still have some underground," said Julie Castillo-Rogez, Dawn project scientist and co-author of the studies, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

What's inside Ceres? Gravity will tell.

Landing on Ceres to investigate its interior would be technically challenging and would risk contaminating the dwarf planet. Instead, scientists use Dawn's observations in orbit to measure Ceres' gravity, in order to estimate its composition and interior structure.

https://phys.org/news/2017-10-dawn-ancient-ocean-remnants-ceres.html

Dawn goes dark.

After an 11-year journey to Vesta and Ceres, the asteroid belt's two largest members, NASA's Dawn spacecraft is expected to run out of thruster fuel in the next few weeks, ending its mission. The robotic explorer, which gave a close-up view of how the presence or absence of water can shape asteroids, will remain tumbling in orbit around Ceres for decades before ultimately crashing into it.

Launched in 2007, Dawn is the only NASA mission to orbit two planetary bodies, a feat made possible by its efficient ion thrusters. In 2011, it arrived at the egg-shaped, 600-kilometer-long Vesta, orbiting for a year before departing for Ceres, where it arrived in 2015.

The two asteroids, which together account for 45% of the belt's mass, turned out to be a tale of contrasts. Parched Vesta has a composition like the terrestrial planets, with an iron core and a dry, rocky surface carved up into canyons, craters, and mountains, remnants of past impacts and volcanism. Dawn was able to verify that a class of meteorites found on Earth are chips off of Vesta, making it a sort of "reverse sample return mission," says Carol Raymond, the mission's principal investigator and a planetary scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

Telescopes had already found water-rich minerals on Ceres, a 900-kilometer-wide body classified as a dwarf planet because of its large size and spherical shape. Dawn revealed the remnants of a frozen ocean topped by a heavily cratered crust of clays and salts. "We could not have imagined it would have looked like this," Raymond says.

https://www.sciencemag.org/news/201...ly_2018-10-17&et_rid=394299689&et_cid=2434316

 

[kamalktk]

Evidence for recent water activity on Ceres.

"Writing in an accompanying comment article, Julie Castillo-Rogez, from the California Institute of Technology's Jet Propulsion Laboratory, said the discovery of hydrohalite was a "smoking gun" for ongoing water activity.

"That material is unstable on Ceres' surface, and hence must have been emplaced very recently," she said."

https://phys.org/news/2020-08-dwarf-planet-ceres-ocean-world.html

 

[EnolaGaia]

Update for topical closure ... The Dawn mission ended when the probe fell silent on 31 October 2018. The Dawn spacecraft was left in a stable orbit around Ceres, where it will remain for years to come.

NASA’s Dawn Mission to Asteroid Belt Comes to End

NASA’s Dawn spacecraft has gone silent, ending a historic mission that studied time capsules from the solar system’s earliest chapter.

Dawn missed scheduled communications sessions with NASA's Deep Space Network on Wednesday, Oct. 31, and Thursday, Nov. 1. After the flight team eliminated other possible causes for the missed communications, mission managers concluded that the spacecraft finally ran out of hydrazine, the fuel that enables the spacecraft to control its pointing. Dawn can no longer keep its antennas trained on Earth to communicate with mission control or turn its solar panels to the Sun to recharge.

The Dawn spacecraft launched 11 years ago to visit the two largest objects in the main asteroid belt. Currently, it’s in orbit around the dwarf planet Ceres, where it will remain for decades. ...

FULL STORY: https://www.nasa.gov/press-release/nasa-s-dawn-mission-to-asteroid-belt-comes-to-end

NOTE: Dawn's functional demise occurred at the same time the plug was pulled on the original Fortean Times Message Board and we undertook our renegade mission to preserve the forum as an independent service sponsored by CFI.

A mere coincidence? You decide!

 

[EnolaGaia]

A Finnish astrophysicist has issued a proposal for a human colony orbiting Ceres - a project he claims can be underway within 2 decades. The proposal makes the case for why Ceres is a better target for human colonization than Mars (at least for the immediate future).

Humans could move to this floating asteroid belt colony in the next 15 years, astrophysicist says

Should we build a 'megasatellite' of human habitats around the dwarf planet Ceres? It's more plausible than it sounds.

Now more than ever, space agencies and starry-eyed billionaires have their minds fixed on finding a new home for humanity beyond Earth's orbit. Mars is an obvious candidate, given its relatively close proximity, 24-hour day/night cycle and CO2-rich atmosphere. However, there's a school of spacefaring thought that suggests colonizing the surface of another planet — any planet — is more trouble than it's worth.

Now, a new paper published Jan. 6 date to the preprint database arXiv offers a creative counter-proposal: Ditch the Red Planet, and build a gargantuan floating habitat around the dwarf planet Ceres, instead.

In the paper, which has not yet been peer-reviewed, astrophysicist Pekka Janhunen of the Finnish Meteorological Institute in Helsinki describes his vision of a "megasatellite" of thousands of cylindrical spacecrafts, all linked together inside a disk-shaped frame that permanently orbits Ceres — the largest object in the asteroid belt between Mars and Jupiter. Each of these cylindrical habitats could accommodate upwards of 50,000 people, support an artificial atmosphere and generate an Earth-like gravity through the centrifugal force of its own rotation, Janhunen wrote. (This general idea, first proposed in the 1970s, is known as an O'Neill cylinder). ...

FULL STORY: https://www.livescience.com/megasatellite-colony-ceres-oneill-cylinder.html

 

[EnolaGaia]

Here are the initial bibliographic details and abstract for the Ceres orbital colony proposal, which is awaiting peer review. The full document is accessible at the link below.

Terraforming the dwarf planet: Interconnected and growable Ceres megasatellite world
Pekka Janhunen

Abstract
We analyse a megasatellite settlement built from Ceres materials in high Ceres orbit. Ceres is selected because it has nitrogen, which is necessary for an earthlike atmosphere. To have 1g artificial gravity, spinning habitats are attached to a disk-shaped megasatellite frame by passively safe magnetic bearings. The habitats are illuminated by concentrated sunlight produced by planar and parabolic mirrors. The motivation is to have a settlement with artificial gravity that allows growth beyond Earth’s living area, while also providing easy intra-settlement travel for the inhabitants and reasonably low population density of 500 /km2. To enable gardens and trees, a 1.5 m thick soil is used. The soil is upgradable to 4 m if more energy is expended in the manufacturing phase. The mass per person is 107 kg, most of which is lightly processed radiation shield and soil. The goal is a long-term sustain- able world where all atoms circulate. Because intra-settlement travel can be propellantless, achieving this goal is possible at least in principle. Lifting the materials from Ceres is energetically cheap compared to processing them into habitats, if a space elevator is used. Because Ceres has low gravity and rotates relatively fast, the space elevator is feasible.

FULL DOCUMENT (PDF): https://arxiv.org/pdf/2011.07487.pdf

 

[eburacum]

This I really like.

 

[eburacum]

Ceres is depicted as holding a rotating environment in The Expanse TV series, but just rotating this dwarf planet would not work. The ice of the planet is not strong enough to hold a rotating structure together, and would fall apart into a rotating disk of rubble.

Here are a couple of ideas I've had for colonising Ceres;
=================

These rotating habitats are designed so that the small amount of local gravity is offset by the conical shape of the hab. The local direction of down will always be perpendicular to the habitat floor.
I call these Doner Kebab-habs.
================================

This shows a rotating ring around Ceres, strengthened by durable materials like graphene and carbon nanoube. The speed of rotation would be very fast to get one gee of centrifugal gravity; more than 7000 km/hr.

 

[Tunn11]

Ceres is depicted as holding a rotating environment in The Expanse TV series, but just rotating this dwarf planet would not work. The ice of the planet is not strong enough to hold a rotating structure together, and would fall apart into a rotating disk of rubble.

Here are a couple of ideas I've had for colonising Ceres;
=================
View attachment 34052
These rotating habitats are designed so that the small amount of local gravity is offset by the conical shape of the hab. The local direction of down will always be perpendicular to the habitat floor.
I call these Doner Kebab-habs.
================================

View attachment 34053
This shows a rotating ring around Ceres, strengthened by durable materials like graphene and carbon nanoube. The speed of rotation would be very fast to get one gee of centrifugal gravity; more than 7000 km/hr.

Doesn't that remind you of Iapetus? If the whole lot had fallen into disuse and got buried in dust, etc.