Fig. 01: The best images available from 2004 - 2015 from the Hubble Space Telescope of the dwarf planet 1 Ceres seem like a 19th century view on Mars. A number of white spots, particularly the one visible in the center of the top image have been detected on the surface of Ceres. It is unclear what they actually are or reveal. Possibly they are major impact basins, from as far ago as the bombardment period, but still expose sublimation from water ice. Little is known about Ceres. However recently in 2013 water vapor ejection from the surface was observed. There may also be a tenuous atmosphere at Ceres. Equatorial surface temperatures can reach minus 38 Celsius during the mid day period. It will not be until the arrival of NASA's unmanned DAWN mission in March 2015 when far greater surface details are better revealed. However after late January 2015 higher than Hubble quality images should come available.
Fig. 02: 1 Ceres is located in the main asteroid belt between the planets Mars and Jupiter. While it is two and a half times the distance from the Sun to Earth solar power is still practical. Nonetheless the surface would only receive approx. one ninth of the Sun light which Earth receives. Radius (km) 476.2±1.7 Area (km2) 2.85 million
Density (kg/m3) 2077±36
Rotation Period (h) 9.075
Semi-Major Axis 2.76 AU
V-band Geometric Albedo 0.090±0.003
Fig. 03: Intensity scale view of 1 Ceres from the Keck II Telescope on Hawaii showing the same face given in Fig. 01 - center left image. Centered on the area now know as Region A at 240 degrees Longitude. The dwarf planet is of oblate spheroid is shape, has an average polar radius of 454.7 km and an equatorial radius of 487.3 km. Therefore the differences in height are approx 32.6 km from the lowest polar to highest equatorial points. If a mean elevation point is taken then the highest peak would be over 16300 metres.
Below I have copied an excellent document from the web by the Author: Andrew Rivkin
The Case for Ceres: Report to the Planetary Science
Decadal Survey Committee
Unresolved, High-Priority Ceres Science Questions
The current state of Ceres research shows it to be a unique object, potentially holding keys to understanding of disparate solar system populations in multiple disciplines. We have identified the following as important science questions concerning Ceres: How did it form and evolve and what is its present-day state?
1) Did Ceres form near its present position or was it transported from the outer solar system? What were Ceres’ starting materials? How much mixing occurred between different planetesimal and protoplanet reservoirs to create Ceres?
Since the last decadal survey, dynamicists have recognized that the jovian planets may have migrated early in solar system history due to the cumulative effects of scattering small bodies, constructing a scenario called the “Nice Model” incorporating the consequences. The Nice Model predicts that objects that formed beyond Neptune could have been transported to the inner solar system in large numbers, populating Jupiter’s Trojan clouds and providing the D-class objects found in the outer asteroid belt (Levison et al. 2009). Ceres’ low density implies an ice to rock ratio comparable to TNOs. This, plus consideration of the Nice Model and the relative frequency of Ceres-sized objects in the inner and outer solar system, led McKinnon (2008) to suggest the possibility that Ceres itself was formed as a TNO and later brought to its current orbit. While the most straightforward history for Ceres includes formation near its current location and kinship to other C-class asteroids, establishing Ceres’ birthplace will be necessary to fully understand its context. The origin of Ceres has direct implications for its long-term evolution as it determined Ceres’ content in volatiles and accretion timeframe (which determines the amount of accreted short-lived radioisotopes.) Means to test this hypothesis are given below.
2) What is the nature of Ceres' interior? Is it differentiated? Does it have an iron core? Does it still support liquid water (within an icy shell)?
Ceres’ shape can be explained by either a differentiated or undifferentiated internal structure. Thermal evolution models indicate that a differentiated interior is the most likely outcome for Ceres (e.g., McCord & Sotin 2005; Castillo-Rogez & McCord, 2009). Conversely, Zolotov (2009) has recently argued that Ceres’ density and shape remain uncertain and do not preclude an undifferentiated interior. For example, Ceres’ low density may be due to a high-porosity interior, since its internal pressures are not sufficient to ensure extensive compaction. Furthermore, Zolotov used geochemical arguments to conclude that the surface composition of Ceres would be different if it had an internal ocean, one able to erupt to the surface. Understanding Ceres’ interior and validating these models will be invaluable for comparative planetological studies of Ceres and other large low-albedo asteroids (like Pallas, Hygiea, or Cybele) and similar-sized icy satellites (like Tethys, Dione, or Ariel) to delimit the phase space where differentiation can be expected, among other comparisons. As an example, the existence of the Main Belt Comets and their association with the Themis asteroid family shows that ice still exists in those bodies (Hsieh and Jewitt 2006). Modeling may ultimately demonstrate whether the ice within these comets is essentially primordial or whether, in contrast, the Themis family parent body was Ceres-like before breakup.
3) What is the geological history of Ceres? Did Ceres experience cryovolcanism? If so, how long did it persist? How much material was exchanged between Ceres’ interior and surface? Were there periods when Ceres’ surface was icy? Or will Ceres be revealed as geologically dead? What will Ceres’ cratering record tell us about its surface and near sub-surface?
If Ceres is differentiated, the melting and freezing of its volatile component would have resulted in tectonic activity (e.g. faulting). The low ice viscosity resulting from the relative warmth of Ceres’ surface may have led to geologically rapid relaxation of impact craters and other topographic features, especially near Ceres’ equator, where temperatures are highest (Ceres’ obliquity is very low). Similar to Europa, Ceres may be undergoing resurfacing possibly in the form of cryovolcanism or venting of water vapor (Li et al. 2006). The slow freezing of an internal ocean, as Ceres’ radiogenic heat wanes, in particular should lead to extensional stresses at the planet’s surface, which would be conducive to such eruptions or venting.
4) What is the nature and origin of Ceres' present surface? Is it primordial rock+ice crust that somehow avoided foundering or was re-exhumed? Or is it a deposit of rocky material that was brought to the surface by water or ice, and left after the ice sublimed or was sputtered away? How has space weathering affected Ceres’ surface? What are the as-yet unidentified constituents of its surface?
Ceres is unique as an ice-rich body with a surface on which ice is unstable. It is unclear whether the current surface of Ceres is a lag deposit of a former (frozen) ocean surface or the non-ice remains of cryovolcanic flows. Another possibility is that it retains remnants of an original mixed rock-ice crust that managed to escape foundering, or which was exhumed after overlying ice was removed by sublimation. We have an incomplete understanding of Ceres’ surface composition. While carbonates and brucite have been identified on Ceres’ surface, there are other absorption bands that have not been associated with specific minerals. A broad band in the near-infrared, also seen in some carbonaceous chondrites, could be due to either magnetite (Fe3O4) or phyllosilicates. Features in the mid-IR have been seen at some times but not others, while interpretation of an absorption consistently seen in the UV has been hampered by a lack of laboratory spectra of analog materials at the relevant wavelengths. Conceivably, the mineralogy on Ceres’ surface could support or refute the hypothesis that Ceres formed farther out in the Solar System.
5) What is the astrobiological potential for Ceres, and/or its complement of prebiotic material? What are the potential mechanisms and frequency of materials recycling and renewal that may affect the potential habitability of Ceres surface or interior? What are the potential geochemical pathways for the transformation and synthesis of indigenous Cerean organic species, now or in the past?
Only in the last few years have we realized that Ceres is a site of astrobiological significance. It has experienced aqueous alteration, it has carbon-bearing species and its pre-alteration assemblage was likely organic-rich. It is apparently ice-rich, and liquid water may persist to this day. Understanding the interactions of organics and water in Ceres’ interior and near-surface may also provide valuable insight into the prebiotic material available for Earth’s accretion. Ceres’ surface composition identified by Milliken and Rivkin (2009) indicates conditions that are much less oxidizing than Mars, and less reducing than Titan, both of which have been considered as key astrobiological targets (Shapiro and Schulze-Makuch 2008). This oxidation state may result in key differences from the chemical reactions found on Mars and Titan, making Ceres’ evolution more pertinent to Earth’s than either of the former objects.
6) Does Ceres have an appreciable atmosphere or exosphere? If so, what is its composition, and is it largely caused by outgassing, sputtering, or other processes? Can its composition constrain Ceres’ origin and internal structure? If Ceres has no such atmosphere or exosphere, what does that imply about its interior and/or volatile content?
Observations of Ceres by the International Ultraviolet Explorer (IUE) by A’Hearn et al. (1992) provided hints of –OH emission off of Ceres’ sunlit pole. These were interpreted as possible evidence of ice sublimation. Since the end of IUE, repeating these observations has been difficult, though groundbased work with improved sensitivity over IUE found no emission (Rousselot et al. 2008). The possibility of near-surface ice (Fanale and Salvail 1989) and a reservoir of a subsurface ice and potential ocean increases the likelihood of a thin atmosphere,exosphere or transient venting existing today. Understanding volatile transport on Ceres will greatly improve our understanding of volatile transport on objects like the Moon, Pluto, and the icy satellites. Measuring any atmosphere on Ceres would also provide constraints on Ceres’ overall volatile content, with implications for Ceres’ history as well as the history of other objects in the main belt. Measurement of D/H in the gas phase, as has been recently done by the Cassini INMS for Enceladus (Waite et al. 2009), would offer the most definitive test of an in situ vs. Kuiper belt origin for Ceres.
Fig. 04: Earth, Moon and Ceres size comparison in near natural colours. While Ceres appears minor in comparison to the Earth, the dwarf planet has a total surface area of 2,850,000 square kilometers or slightly more than that of Argentina.
The dwarf planet Ceres has fascinated me for a long time now. In 1980 as a 12 years old I "discovered" it in a school atlas of the Solar System and ever since then I guess I have been under its ever so slight gravitational pull. In about 1981 watching late night TV, and after Blakes Seven, I saw for the first time the 1959 episode of the Twilight Zone: The Lonely. The program is about a convicted criminal named James A Corry sentenced to 50 years solitary confinement on a remote asteroid 9 million miles from the Earth for a crime he committed in self defense. There he is routinely visited by a supply ship Captained by the sympathetic Allan Bee who at one point gives Corry a very special gift - a robot in the form of a female companion named Alicia. Low budget and even for a 12 year old in Australia it was clearly evident that they had shot it in Death Valley which it turned out to be (Zabriskie Point / Desolation Canyon). While there is no reference in this classic TV drama that the main character Corry is spending his penal sentence on Ceres he is indeed on an asteroid which has nothing for 6000 miles wherever one goes north to south nor 4000 miles east to west! In spite of the fact that these great distances have little in common to 1Ceres, when I saw this TV drama for the first time all those years ago there was no doubt in my mind that Corry was indeed on Ceres! The distances do however imply he is on an oblate spheroid! Coincidentally and about 3 decades later I was recommended by a friend to watch on DVD the little known, but highly entertaining cult movie The American Astronaut, which was directed by who other than a certain Cory McAbee. It can be no coincidence that he also was under the gravitational influence of a distant dwarf planet and had been inspired by The Lonely to set his seminal film on Ceres! Now as the time period closes when the dwarf planet Ceres is no longer a lonely, and former asteroid, in the vast void of space I want to present some scenarios about a special place in the minds of some for quite a while now with the Cererian Sentinel.
Fig. 05: Sunrise over the pre dawn dwarf planet 1 Ceres centering on Reg A - cryovolcanic point (Long E 231 / Lat N 22 degrees). It is currently uncertain what the white spots visible in the 2004 Hubble Images actually are, but for these possibilities: Cryovolcanic outflow points and springs, including outflow fallout areas and frost. In my illustration above I present my own scenario of the dwarf planet 1 Ceres in December 2014. The brown area to the west of Reg A is oxidised iron material from a late bombardment period impact which likely caused the cryovolcanic basin to exist. Pizza on the other side of this dwarf planet on the other hand (centred on Long E 127 / Lat N 20 degrees) is a Chaos region of surface regolith and convection ice - sub surface cryovolcanism point. There are possibly long term or even seasonal alterations in the water vapor outflow at these two principal points (white spots). There are numerous other white spots detected which areas associated to either both Reg A and Piazzi on 1 Ceres and cryovolcanic springs, sublimation points, water vapor cloud formations and fallout areas of water ice going through a rapid process of sublimation. However vast areas of the north polar region and northern hemisphere are subject to water ice frost which has a definitive seasonal - frostshoreline. 1 Ceres has a tenuous, but oxygen rich atmosphere - primary cause of the iron oxidation areas. Atmospheric "air" pressure may be approx 0.1519 Mbar (0.015 psi) 4500m below the mean level and increase in even lower laying regions such as Region A, Piazzi and both polar regions. The dark areas in particularly the Reg A basin, its cryovolcanic area, as well as the northern hemisphere Polar and sub-polar regions - may show evidence of a near to surface biosphere - low temperature dwelling psychrophiles upwards to even lichens. References Figs: 01, 03, 06 and my own extrapolations Sept. 2014.
Fig. 06: ESA’s Herschel space observatory has discovered water vapour around Ceres, the first unambiguous detection of water vapour around an object in the asteroid belt. Approximately 6 kg of water vapour is being produced per second from two principal regions. They being from the Piazzi Region at 120 degrees Longitude and the area now known as Region A at 240 degrees Longitude.
Fig. 07: Southfacing Monolithic structure of rocky / clay materials, remnant from water ice retreat / erossive action and subsequent space weathering in the subpolar region near Piazzi Basin.Springs at right and orographic cloud formation left.
Fig. 08: Leaping 30m off the surface of the dwarf planet 1 Ceres - here a hypothetical 1 Ceres Biosphere (lichen and or carbon / coral / clay structure) in the water vapor and oxygen rich cryovolcanic water ice / chaos field of the northern Piazzi Basin. Sub-surface aquifers due to the internal heat sources and or the processes of volatiles released from silicate rich hydro / thermal vents may possibly support microbial to macro life forms in or close to the convection ice and clay rich soils or even rocks. While there are extremely low temperature (below - 30 degrees celsius on the surface of 1 Ceres) there may however be sub-surface dwelling psychrophiles or at least archaeo - single celled microorganisms. Their habitat may be within convection ice / reg material / antifreeze liquids etc. My hypothetical scene illustrated would be located at greater than 4500 m below the 1 Ceres datum. Here a viable atmosphere may be present allowing such extremophiles to coexist. Visible also is a hypothetical moon of 1 Ceres - Proserpina.
Fig. 09: Two moons rising over the eastern equatorial horizon on 1 Ceres. Over 230 minor planets in our solar system are known to have moons and there are approx 84 in the asteroid belt - with 5 minor planets having two moons. Therefore it may not come as a surprise that 1 Ceres also has at least one natural satellite and certainly quasi satellites like the Earth. If there were to be two moons of 1 Ceres, very small as not to have yet been detected, perhaps they should be named by the International Astronomical Union as Liber and Libera. It was the late Republican era Roman - Cicero who described Liber (male) the guardian of plebeian freedom and Libera (female) goddess of wine, fertility and also freedom, as Ceres' children. In 2015 the term freedom has great significance worldwide in these troubled times - Liber and Libera may make their selves known to us.
Fig. 10: Since its discovery by Giuseppe Piazzi in 1801 to the present, I would best describe that we are still in the Science Discovery Period 1.0 when concerning the dwarf planet Ceres. However 2015 is the transitory period to the Science Discovery Period 2.0 with the arrival of the DAWN mission. Inevitably will follow other unmanned missions such as robotic Polar Landers and Curiosity type rovers. Human spaceflight to the dwarf planet 1 Ceres may not be until as late the 2050s although my guess is somewhere between 2032 and 2045/46.Sending humans to Ceres initially could involve trial and tested Luna Lander technology by as early as the 2030s - where: Frank E. Laipert, James M. Longuski, Low-Thrust Trajectories for Human Missions to Ceres, Acta Astronautica, http://dx.doi.org This proposal for a Low Trust Trajectory would spiral the Earth for up to two years before crew would depart for Ceres in a CTV (crew transfer vehicle) configured in LEO. For their study a trajectory from Earth to Ceres that delivers 125 Mg (i.e.metric tons) of mass in 270 days, while minimizing the total departure mass. This 125 Mg includes the propulsion system mass.
In my own conceptual illustration above I have made a scenario for the 1 Ceres - Piloted / Electric Ion Propulsion CTV (5 crew transfer vehicle) in its full configuration - without the 1 Ceres trajectory rocket booster. This ship would be made up of several segments launched separately for LEO assemblage by up to 3 heavy lift vehicles / 1 crew launch vehicle. The CTV would be up to 46.6m in length (including configured rover / hab - see below). The crew of this ship would travel with the addition of a 1 Ceres gravity twin hab centrifuge - achieved at a 12m radii for comfort and adjustment for a long duration mission of up to 2.5 years round trip. A 30cm water jacket (cryo and or waste) surrounding both crew habitat areas, hab egress passages, ship's core and command module walls would suffice against solar and cosmic radiation mitigation. Electric Ion propulsion, after the 1 Ceres trajectory from Earth is launched, would allow the ship to travel up to 3 km/per second en route to Ceres. There would be required an additional heavy lift vehicle - the STV (supply transfer vehicle) sent to Ceres long before the CTV has set course. It carrying an inflatable surface hab / power source / robotics / airlock and Earth return propellant).
Fig. 11: For possible establish of scientific stations and depending on weather 1 Ceres proves to have a biosphere there may required anything starting with an orbital hab to even a geostationary platform with 1 Ceres centrifuge / crew quarters. If 1 Ceres has no detectable biosphere than there may be the use of limited pathway all terrain mobile habitats. Numerous surface missions into obtaining possible bio signatures and other atmospheric gases, drilling clays and or water ice cores and sampling water vapor / soil and rock samples. Scenario (illustrated) for an ATRH - all terrain rover hab / extra-planetary for long duration on the surface of Ceres. Such vehicles may be powered by ASRG (advanced Stirling radioisotope generators). Travel navigation: Stn / sat. interface / data base. Autonomous - 9 wheel ind drive, high torque 3.6 km p/h max with the aid of low power radar and or 3D laser navigation. Atmospheric Stn: vacuum pumps for the extraction of local oxygen / water vapor / Human waste 99.99% recycle. 3 crew - 120 day exploratory vehicle. 3 crew Unit Habs / Airlock Core surface egress to Orbital Stn.
Fig. 12: Concept for a 3 face diamond optical / digital display / transparent tablet computer with magnetic induction pathways / multiple configuration (3 face) and robotics operable in low gravity (1 Ceres) through segway gyro system. System would be linked to ATRH main AI command centre, individual crew / crews' suite interface and small robotics systems. Tablet Dog Systems 2012.
Fig. 13: In the longer time period there may possibly be global Terra-formation of the dwarf planet 1 Ceres - pictured above. In the early phases of a permanent human presence on Ceres firstly Macro Terra-formation or Para Terra-formation (World housing) would probably take place. This would be in or beyond the Period 3.0 (beyond 2070). The components for the colonies' main habitats would possibly be a number of linear cities suspended over the primary Para Terra-formed region(s) from where the colonists would inhabit. Note that the natural oblate spheroid of Ceres would appear more spherical if only global Terra-formation were to take place, as water presently locked up in the porous interior would move towards the lowest surface points at the poles. Therefore these lowest polar points would become the deepest ocean points on Ceres. Ceres now may have a tenuous atmosphere of oxygen, however to sustain a breathable earth-like atmosphere would be virtually impossible to achieve unless the dwarf planet is to have firstly established a magnetosphere. If Ceres has a large enough iron core, or any iron for that fact, perhaps an artificial magnetosphere could be created. This project would involve technology still unavailable such as cold fusion. However with the vast sub-surface ocean which Ceres evidently has the most fundamental resource required - water is in abundance. It may even be the future colony's highest trade able commodity for export to a certain Mars colony or even to the Earth. How Global Terra-formation would impact or influence any possible indigenous life forms is an important ethical and moral question.
As transporting raw materials from Ceres to Mars would be less energy intensive than from the Earth, the dwarf planet makes a valuable resource for inevitable Mars colonization. Macro Terra-formation sites on Ceres would require carbon nano-tube structures to establish and contain an earth-like climate. They would also importantly allow for enclosed cocoon like space for the full protection from the vacuum of space and harm full solar / cosmic rays. Due to the surface gravity on Ceres being only 3% that of the Earth or 0.028 g it would have peculiar effects on hydro-static equilibrium and plant growth. Construction of Earth gravity centrifuges however would be a remedy for the long term settlers well being. The Ceres Colony would have to become near self-sufficient due to the distances and costs involved into shipping in supplies from the Earth. Human and technological capital would initially be imported. If resource rich the asteroid belt will provide for a growing Ceres colony and or a transfer station for the exportation of goods.
Fig. 14: Global Terra-formation Period 1.0 (2100s and beyond). During the Science Discovery Period 2.0 (2015 - 2070s) it will become clear whether Ceres has, dose or can support life. Establishing a colony on Ceres may be possible, however even for this small world, it would involve an enormous enterprise for the completion of global Terra-formation. Once terraformation has been established the low gravity of Ceres would effect the growth of plants and animals on its surface. Bio engineered plants imported from the earth my evolve into a mega flora and would thrive in such an environment where there are poor soils and low light levels. Areas at low altitudes, but close to the equatorial region, geothermal or cryovolcanic regions would also assist in the early stages for global terraformation.
Illustrations in Fig. 05 and 07 - 14 Copyright by Sean D. 2015
The Case for Ceres: Report to the Planetary Science