Trans-Neptunian Dwarf Planets

2021 ◽  
Author(s):  
Bryan Holler
Keyword(s):  
Solar System ◽  
Surface Composition ◽  
Planetary Science ◽  
Chemical Diversity ◽  
Asteroid Belt ◽  
Dynamical Structure ◽  
Forthcoming Article ◽  
Cold Temperatures ◽  
Dwarf Planets ◽  
Physical And Chemical

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Planetary Science. Please check back later for the full article. The International Astronomical Union (IAU) officially recognizes five objects as dwarf planets: Ceres in the main asteroid belt between Mars and Jupiter; and Pluto, Eris, Haumea, and Makemake in the trans-Neptunian region beyond the orbit of Neptune. However, the definition used by the IAU applies to many other trans-Neptunian objects (TNOs) and can be summarized as any nonsatellite large enough to be rounded by its own gravity. Practically speaking, this means any nonsatellite with a diameter >400 km. In the trans-Neptunian region, there are more than 100 objects that satisfy this definition, based on published results and diameter estimates. The dynamical structure of the trans-Neptunian region records the migration history of the giant planets in the early days of the solar system. The semi-major axes, eccentricities, and orbital inclinations of TNOs across various dynamical classes provide constraints on different aspects of planetary migration. For many TNOs, the orbital parameters are all that is known about them, due to their large distances, small sizes, and low albedos. The TNO dwarf planets are a different story. These objects are large enough to be studied in more detail from ground- and space-based observatories. Imaging observations can be used to detect satellites and measure surface colors, while spectroscopy can be used to constrain surface composition. In this way, TNO dwarf planets not only help provide context for the dynamical evolution of the outer solar system, but also reveal the composition of the primordial solar nebula as well as the physical and chemical processes at work at very cold temperatures. The largest TNO dwarf planets, those officially recognized by the IAU, plus others such as Sedna, Quaoar, and Gonggong, are large enough to support volatile ices on their surfaces in the present day. These ices are able to exist as solids and gases on some TNOs, due to their sizes and surface temperatures (similar to water ice on Earth) and include N2 (nitrogen), CH4 (methane), and CO (carbon monoxide). A global atmosphere composed of these three species has been detected around Pluto, the largest TNO dwarf planet, with the possibility of local atmospheres or global atmospheres at perihelion for Eris and Makemake. The presence of nonvolatile species, such as H2O (water), NH3 (ammonia), and organics provide valuable information on objects that may be too small to retain volatile ices over the age of the solar system. In particular, large quantities of H2O mixed with NH3 points to ancient cryovolcanism caused by internal differentiation of ice from rock. Organic material, formed through radiation processing of surface ices such as CH4, records the radiation histories of these objects as well as providing clues to their primordial surface compositions. The dynamical, physical, and chemical diversity of the >100 TNO dwarf planets are key to understanding the formation of the solar system and subsequent evolution to its current state. Most of our knowledge comes from a small handful of objects, but we are continually expanding our horizons as additional objects are studied in more detail.

GAUSS: Towards Sample Return from Dwarf Planet Ceres

2020 ◽  
Author(s):  
Xian Shi ◽  
Keyword(s):  
Solar System ◽  
Asteroid Belt ◽  
Global Ocean ◽  
Geological Time ◽  
Sample Return ◽  
Dawn Mission ◽  
Dwarf Planets ◽  
Geological Features ◽  
History Of ◽  
Physical And Chemical

<p>GAUSS (Genesis of Asteroids and EvolUtion of the Solar System) is a mission concept for the future exploration of Ceres. As both the largest resident of the main asteroid belt and the only dwarf planet in the inner Solar System, Ceres holds critical information for probing the evolution and habitability of our Solar System. NASA’s DAWN mission performed the by far most comprehensive investigation of Ceres during its over three year in-orbit operation around this unique world. Data collected by remote sensing instruments revealed an amazingly diverse landscape comprising different types of geological features. Beneath its volatile- and organic-rich surface, Ceres might have once possessed a global ocean, the remnants of which possibly still exist today as pockets of brine between the mantle and the crust. Hydrothermal activities that took place in recent geological time transferred materials deep inside Ceres to its surface, forming several outstanding surface features that are optimal for future sampling. Similar processes could occur on other ocean worlds in the Solar System, making Ceres a benchmark case for studying the evolution and habitability of these objects in general.</p> <p>To fully understand the physical and chemical evolution of Ceres, high resolution analyses of samples are necessary. With cryogenic sample return as its final step, the GAUSS project aims to answer the following key questions:</p> <ul> <li>What is the origin of Ceres and the origin and transfer of water and other volatiles in the inner solar system?</li> <li>What are the physical properties and internal structure of Ceres? What do they tell us about the evolutionary and aqueous alteration history of icy dwarf planets?</li> <li>What are the astrobiological implications of Ceres? Was it habitable in the past and is it still today?</li> <li>What are the mineralogical connections between Ceres and our current collections of primitive meteorites?</li> </ul>

scholarly journals Visualization and Analysis of Data from Small-Body Missions with NASA’s Solar System Treks Portals

2020 ◽  
Author(s):  
Brian Day ◽  
Emily Law ◽  
Keyword(s):  
Solar System ◽  
Small Body ◽  
Planetary Science ◽  
Asteroid Belt ◽  
Sample Collection ◽  
Science Division ◽  
Small Bodies ◽  
Sample Site ◽  
Surface Sample ◽  
Data Products

<p>This presentation provides an overview of portals within NASA’s Solar System Treks Project (SSTP) that specifically target small bodies within our Solar System. These, and all of the portals in the suite of Solar System Trek portals, are available at https://trek.nasa.gov.</p> <p>These portals each allow for visualization of different data products in 2D maps with various projections. They also allow users to conduct interactive 3D flyovers. The VR tool allows users to generate their own virtual reality flyovers for any user-defined paths along the bodies’ surfaces. Other tools let users measure distances, generate elevation plots, and create 3D print files for user-defined regions or the entire body.</p> <p>JAXA’s Hayabusa 2 mission recently completed a campaign of reconnaissance, sample collection, and rover deployment at the near-Earth asteroid (162173) Ryugu. JAXA is providing mission data to SSTP, which is incorporating it into the new Ryugu Trek portal (https://trek.nasa.gov/ryugu). The internationalized user interface features controls in both English and Japanese. The portal’s bookmarks feature takes users to particular areas of interest for more detailed looks at specific landforms and sites. On Ryugu, we focus on the surface sample site, impactor and sub-surface sample site, as well as landing sites and traverse paths for the HIBOU, OWL, and MASCOT rovers. We also highlight the first landforms on Ryugu to have been given official IAU names.</p> <p>While Hayabusa2 was exploring Ryugu, NASA’s OSIRIS-REx mission began conducting a detailed examination of the asteroid (101955) Bennu, another near-Earth object. At the request of NASA’s Planetary Science Division and the OSIRIS-REx mission, SSTP began implementation a new portal for the asteroid Bennu, featuring data that is being returned from OSIRIS-REx. The Bennu Trek portal (https://trek.nasa.gov/bennu) reveals Bennu’s top-like shape, a fascinating commonality with Ryugu. It also reveals details of Bennu’s intensely boulder covered terrain. Bookmarked features include Nightingale, Sandpiper, Osprey, and Kingfisher, the top four candidates for sample collection. We also highlight the first landforms on Bennu to have been given official IAU names. Each of these features were singled out as landmarks for OSIRIS-REx’s Natural Feature Tracking (NFT) navigation method that will be used to guide the spacecraft down to its surface sample collection site.</p> <p>In its investigations of Vesta and Ceres, NASA’s Dawn mission has returned spectacular data of the surfaces of these two prominent small bodies within the asteroid belt. This presentation will showcase the use of the Ceres Trek (https://trek.nasa.gov/ceres) and Vesta Trek (https://trek.nasa.gov/vesta) portals and demonstrate how they can be used to visualize and analyze particularly interesting landforms such as the pitted terrain on Vesta and relic cryovolcanoes on Ceres.</p> <p>Under development at this time is a new portal for Mars’ larger Moon, Phobos. This portal will make extensive use of data from ESA’s Mars Express. It is being designed in collaboration with JAXA to support Japan’s upcoming Martian Moons eXploration (MMX) mission. This presentation will provide a preview of a prototype for Phobos Trek.</p> <p>Other Near-Earth asteroids being considered as candidates for future portals include (433) Eros utilizing data gathered by the NEAR Shoemaker mission, and (25143) Itokawa using data from JAXA’s Hayabusa mission. Together, a growing collection of small body Trek portals would enhance capabilities for comparative planetology among this fascinating class of objects. </p> <p>All of these products are efforts in the NASA Solar System Treks Project, available at https://trek.nasa.gov. NASA's Solar System Trek online portals provide web-based suites of interactive data visualization and analysis tools to enable mission planners, planetary scientists, students, and the general public to access mapped data products from past and current missions for a growing number of planetary bodies. These portals are being used for site selection and analysis by NASA and its international partners, supporting upcoming missions. In addition to demonstrating the capabilities of selected portals in this presentation, we will solicit input from the community for ideas for future enhancements.</p> <p>The authors would like to thank the Planetary Science Division of NASA’s Science Mission Directorate, NASA’s SMD Science Engagement and Partnerships, the Advanced Explorations Systems Program of NASA’s Human Exploration Operations Directorate, and the Moon to Mars Directorate for their support and guidance in the development of the Solar System Treks.</p>

Terrestrial Analogs to Planetary Volcanic Processes

2021 ◽  
Author(s):  
Peter J. Mouginis-Mark ◽  
Lionel Wilson
Keyword(s):  
Solar System ◽  
Planetary Science ◽  
Lava Flows ◽  
Forthcoming Article ◽  
Shield Volcanoes ◽  
System P ◽  
Volcanic Processes ◽  
Topographic Characteristics ◽  
Solar System Exploration ◽  
Spacecraft Data

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Planetary Science. Please check back later for the full article. More than 50 years of solar system exploration has revealed the great diversity of volcanic landscapes beyond the Earth, be they formed by molten rock, liquid water, or other volatile species. Classic examples of giant shield volcanoes, solidified lava flows, extensive ash deposits, and volcanic vents can all be identified but, with the exception of eruptions seen on the Jovian moon Io, none of these planetary volcanoes have been observed in eruption. Consequently, the details of the processes that created these landscapes must be inferred from the available spacecraft data. Despite the increasing improvement in the spatial, temporal, compositional, and topographic characteristics of the data for planetary volcanoes, details of the manner in which they formed are not clear. However, terrestrial eruptions can provide numerous insights into planetary eruptions, whether they result in the emplacement of lava flows, explosive eruptions due to volatiles in the magma, or the interaction between hot lava and water or ice. In recent decades, growing attention has therefore been directed at the use of terrestrial analogs to help interpret volcanic landforms and processes on the terrestrial planets (Mercury, Venus, the Moon, and Mars) and in the outer solar system (the moons of Jupiter and Saturn, the larger asteroids, and potentially Pluto). In addition, terrestrial analogs not only provide insights into the geologic processes associated with volcanism, but they can also serve as test sites for the development of instrumentation to be sent to other worlds, as well as serve as a training ground for manned and unmanned explorers seeking to better understand volcanism throughout the solar system.

Landslides in the Solar System

2021 ◽  
Author(s):  
Maria Teresa Brunetti ◽  
Silvia Peruccacci
Keyword(s):  
Solar System ◽  
Slope Failure ◽  
Visual Analysis ◽  
Planetary Science ◽  
Aerial Photographs ◽  
Mass Movements ◽  
Submarine Landslides ◽  
Forthcoming Article ◽  
Landslide Mass ◽  
Solid Bodies

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Planetary Science. Please check back later for the full article. Landslides are gravity-driven mass movements of rock, earth, or debris. All of these surface processes occur under the influence of gravity, meaning that they globally move material from higher to lower places. Outside Earth, these structures were first observed in a lunar crater during the Apollo program, but mass movements have been spotted on several rocky worlds (solid bodies) in the solar system, including icy satellites, asteroids, and comets. On Earth, landslides have the effect of shaping the landscape more or less rapidly, leaving a signature that is recognised through field surveys and visual analysis, or automatic identification, on aerial photographs or satellite images. Landslides observed on Earth and in solid bodies of the solar system are of different types on the basis of their movement and the material involved in the failure. Material is either rock or soil (or both) with a variable fraction of water or ice; a soil mainly composed of sand-sized or finer particles is referred to as earth, while it is called debris if composed of coarse fragments. The landslide mass may be displaced in several types of movement, classified generically as falling, toppling, sliding, spreading, or flowing. Such diverse characteristics mean that the size of a landslide (e.g., area, volume, fall height, length) can vary widely. For example, on Earth, their areas range up to eleven orders of magnitude, while their volumes vary by eighteen orders, from small rock fragments to huge submarine landslides. The classification of extraterrestrial landslides is based on terrestrial analogs, which have similarities and characteristics that resemble those found on the planetary body. This morphological classification is made regardless of the geomorphological environment or processes that may have triggered the slope failure. Comparing landslide characteristics on various planetary bodies helps to understand the effect of surface gravity on landslide initiation and propagation, which can be of tremendous importance when designing manned and unmanned missions with landings on extraterrestrial bodies. Regardless of the practical applications of such study, knowing the morphology and surface dynamics that shape solid bodies in the space surrounding the Earth is something that has fascinated the human imagination since the time of Galileo.

scholarly journals Organic matter and water from asteroid Itokawa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Q. H. S. Chan ◽  
A. Stephant ◽  
I. A. Franchi ◽  
X. Zhao ◽  
R. Brunetto ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solar System ◽  
Parent Body ◽  
Asteroid Belt ◽  
True Nature ◽  
Water Ice ◽  
Nanocrystalline Graphite ◽  
Terrestrial Water ◽  
Solar System Bodies ◽  
Small Dust

AbstractUnderstanding the true nature of extra-terrestrial water and organic matter that were present at the birth of our solar system, and their subsequent evolution, necessitates the study of pristine astromaterials. In this study, we have studied both the water and organic contents from a dust particle recovered from the surface of near-Earth asteroid 25143 Itokawa by the Hayabusa mission, which was the first mission that brought pristine asteroidal materials to Earth’s astromaterial collection. The organic matter is presented as both nanocrystalline graphite and disordered polyaromatic carbon with high D/H and 15N/14N ratios (δD =  + 4868 ± 2288‰; δ15N =  + 344 ± 20‰) signifying an explicit extra-terrestrial origin. The contrasting organic feature (graphitic and disordered) substantiates the rubble-pile asteroid model of Itokawa, and offers support for material mixing in the asteroid belt that occurred in scales from small dust infall to catastrophic impacts of large asteroidal parent bodies. Our analysis of Itokawa water indicates that the asteroid has incorporated D-poor water ice at the abundance on par with inner solar system bodies. The asteroid was metamorphosed and dehydrated on the formerly large asteroid, and was subsequently evolved via late-stage hydration, modified by D-enriched exogenous organics and water derived from a carbonaceous parent body.

PLANETARY SCIENCE: How Neptune Pushed the Boundaries of Our Solar System

Science ◽  
2004 ◽  
Vol 306 (5700) ◽  
pp. 1302-1304 ◽  
Author(s):  
A. Morbidelli
Keyword(s):  
Solar System ◽  
Planetary Science

scholarly journals The Grand Tack model: a critical review

2014 ◽  
Vol 9 (S310) ◽  
pp. 194-203 ◽  
Author(s):  
Sean N. Raymond ◽  
Alessandro Morbidelli
Keyword(s):  
Solar System ◽  
Building Blocks ◽  
Protoplanetary Disk ◽  
Giant Planets ◽  
Asteroid Belt ◽  
Terrestrial Planets ◽  
Saturn’S Satellites ◽  
Internal Inconsistency ◽  
Solar System Bodies ◽  
Gas Accretion

AbstractThe “Grand Tack” model proposes that the inner Solar System was sculpted by the giant planets' orbital migration in the gaseous protoplanetary disk. Jupiter first migrated inward then Jupiter and Saturn migrated back outward together. If Jupiter's turnaround or “tack” point was at ~ 1.5 AU the inner disk of terrestrial building blocks would have been truncated at ~ 1 AU, naturally producing the terrestrial planets' masses and spacing. During the gas giants' migration the asteroid belt is severely depleted but repopulated by distinct planetesimal reservoirs that can be associated with the present-day S and C types. The giant planets' orbits are consistent with the later evolution of the outer Solar System.Here we confront common criticisms of the Grand Tack model. We show that some uncertainties remain regarding the Tack mechanism itself; the most critical unknown is the timing and rate of gas accretion onto Saturn and Jupiter. Current isotopic and compositional measurements of Solar System bodies – including the D/H ratios of Saturn's satellites – do not refute the model. We discuss how alternate models for the formation of the terrestrial planets each suffer from an internal inconsistency and/or place a strong and very specific requirement on the properties of the protoplanetary disk.We conclude that the Grand Tack model remains viable and consistent with our current understanding of planet formation. Nonetheless, we encourage additional tests of the Grand Tack as well as the construction of alternate models.

Assembling aliens to explore the Solar System

2021 ◽  
Author(s):  
Catarina Leote ◽  
Sérgio Pereira ◽  
João Retrê ◽  
Pedro Machado ◽  
Gabriella Gilli ◽  
...  
Keyword(s):  
Solar System ◽  
Learning Strategies ◽  
Science Communication ◽  
Planetary Science ◽  
Lessons Learned ◽  
Board Game ◽  
Whole Process ◽  
Informal Educators ◽  
Low Exposure ◽  
Challenging Situation

<p><strong>Assembling aliens to explore the Solar System</strong></p> <p>After analysing the school curricula until 7th grade (13 years old), we concluded that, at least in Portugal, there is a limited coverage of astronomy subjects. This situation is also often accompanied by limited training of primary and medium school teachers and limited availability of resources in their mother tongues, as language can also be a barrier for the use of existing resources. In addition, some astronomy concepts require a level of abstract thinking that might be discouraging for some children. The end result is that some children will have a low interest in astronomy, not only because of their personal preferences but as a consequence of low exposure to the subject or a negative perception towards it. To address this situation, the Science Communication Group of Instituto de Astrofísica e Ciências do Espaço (IA) developed a board game about the Solar System, aimed at children from 6 to 12 years old, and adapted to both formal and informal educational contexts. This project, “Help your Alien – A Solar System Game”, was funded in 2019 by the Europlanet Society through its Public Engagement Funding Scheme.</p> <p><strong>Why a board game?</strong></p> <p>By opting for a board game instead of a digital platform, we made the conscious decision of valuing the power of storytelling and social interaction as engaging and focus-promoting learning strategies, unlike the information and stimuli overload sometimes present in digital environments. Another choice made to make the game as appealing and relatable to our target public as possible was to start with a more familiar perspective, biology, as children of this age group will certainly be familiar with “animals” and their characteristics. We made a leap forward towards astrobiology, and created imaginary aliens somehow adapted to their planets and moons. While trying to assemble these imaginary creatures, in a 3-piece puzzle, the game players have to gather information about different objects of the Solar System and discover the home planet of their assembled aliens.  Another reason for creating a board game was the possibility of reaching different publics, in particular those perhaps not immediately interested in astronomy. With “ET – A Solar System Adventure”, we hope to engage children but also their families (parents, grandparents, siblings…), just for the sake of playing, while exposing them to knowledge about the Solar System.</p> <p><strong>Development of the game</strong></p> <p>The game was developed in a collaborative creative process by members of the Science Communication Group and researchers in Planetary Sciences of the IA, combining knowledge in science communication and different publics with scientific knowledge. Even though the game mechanics was inspired in already existing and well-tested games, the whole process of creating this game involved many challenges, from defining the level of complexity while keeping the game engaging, to the adventure of “creating” aliens somehow physiologically adapted to different planets and moons of the Solar System. Mistakes were made and the team had to adapt to the unexpected challenging situation of a pandemic. This resulted in many lessons learned that we hope to share with the community. The game is now at its final stages of production, with the prototype being converted into a polished version with professional illustration and design. A “Print and Play” version in Portuguese and English will soon be made available online on our website. Physical copies will also be produced depending on funding.</p> <p>In our presentation, we will present our game, as well as the premises and goals behind it, its development process, the challenges found along the way, the lessons learned and some strategies to cope with the “new normality” imposed by Covid-19, while advancing the project. We hope the presentation of “ET – A Solar System Adventure” in the EPSC2021 will help to promote this tool for planetary science education among formal and informal educators and to find international collaborations for the translation and local promotion of the game, as well as additional funding for the production of physical copies in different languages.</p>

Gaia spectroscopic view of the asteroid main belt and beyond

2021 ◽  
Author(s):  
Marco Delbo ◽  
Laurent Galluccio ◽  
Francesca De Angeli ◽  
Paolo Tanga ◽  
Alberto Cellino ◽  
...  
Keyword(s):  
Solar System ◽  
Preliminary Investigation ◽  
Planetary Science ◽  
Reflectance Spectra ◽  
Physical Parameters ◽  
The Novel ◽  
Main Belt ◽  
Compositional Gradient ◽  
Solar System Object ◽  
Science Community

<div class="">Asteroids reflectance spectra in the visible light will be one of the novel products of the Gaia Data Release 3 (DR3). These spectra are produced from Gaia observations obtained by means of the blue and red photometers — the so-called BP and RP, respectively. We will review the strategy adopted to produce asteroid reflectance spectra from BP-RP data, focusing on the choice of spectro-photometric calibrations computed taking into account solar system object astrometry and suitable lists of solar-analog stars.</div> <div class=""> </div> <div class="">Our preliminary investigation shows that we will be able to obtain reflectance spectra for asteroids as small as some km in the main belt, by exploiting the fact that each object has been observed multiple times by Gaia. We will show the capability of Gaia to probe the detailed compositional gradient of the main belt down to small sizes and to study correlations between spectral classes and other asteroid physical parameters, such as albedo and size.</div> <div class=""> </div> <div class="">Concerning the brightest asteroids, we expect to have substantial signal at wavelengths shorter than 450 nm, allowing Gaia to examine this region of the spectrum that has been poorly investigated by ground-based asteroid spectroscopic surveys. This region is characterised by the presence of a reflectance downturn that is diagnostic for the composition of classes of primitive asteroids, for instance those including the parent bodies of carbonaceous chondrites. These asteroids may have played an important role for the delivery of prebiotic compounds to Earth during the early phases of solar system' s history and, as such, are at the center of attention of the planetary science community. </div>

The formation and evolution of the solar system

2021 ◽  
Vol 03 (01) ◽  
pp. 85-87
Author(s):  
Türkanə Mirzəli qızı Əliyeva ◽  
◽  
Vəfa Əjdər qızı Qafarova ◽  
Keyword(s):  
Solar System ◽  
Kuiper Belt ◽  
New Horizons ◽  
T Tauri ◽  
Dwarf Planets ◽  
Celestial Bodies ◽  
Extensive Information ◽  
Formation And Evolution ◽  
Red Giant ◽  
Planet X

The article provides extensive information on the formation, evolution and structure of the solar system. It also discusses the planets of the solar system and the dwarf planets. Its noted that the Kuiper objects are the celestial bodies which belongs to the solar system. NASA's New Horizons spacecraft is currently helps studying four objects in the Kuiper belt. There is also talked about TTauri type stars. The article discusses the future transformation of the Sun from a Red Giant to a White Dwarf. Key words: Kuiper Belt, T Tauri Star, Dwarf Planets, Planet X

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