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From Kuiper Belt to Oort Cloud
Published in Thomas Hockey, Jennifer Lynn Bartlett, Daniel C. Boice, Solar System, 2021
Thomas Hockey, Jennifer Lynn Bartlett, Daniel C. Boice
Collisions or close encounters with other KBOs deflect some objects out of the Kuiper Belt, either ejected to interstellar space or hurtling into the inner Planetary System. As these deflected bodies approach the Sun, their volatile ices will sublimate to form comets with their familiar comae and tails.
Stability of Kinetic Alfven Wave (Kaw) In A Cometary Plasma With Streaming Electrons And Protons
Published in B. Raneesh, Nandakumar Kalarikkal, Jemy James, Anju K. Nair, Plasma and Fusion Science, 2018
G. Sreekala, Sijo Sebastian, Manesh Michael, E. Savithri Devi, C. P. Anilkumar, chandu venugopal
KAWs can be excited in plasmas by many ways including temperature anisotropy, velocity shear, inhomogeneities in density and magnetic field, etc. [15]. When a comet approaches the Sun to within a few AU, the surface of the nucleus begins to evaporate; these evaporated molecules boil off and carry small solid particles with them, forming the comet’s coma of gas and dust. There is a change of density inhomogeneity and temperature anisotropy in a comet when the solar wind sweeps past the comet. The drifting of the solar wind electrons and protons is the cause of a huge increase in free energy and which in turn drives instabilities.
C
Published in Splinter Robert, Illustrated Encyclopedia of Applied and Engineering Physics, 2017
[astronomy/astrophysics, mechanics] Celestial object consisting of frozen medium and solids, leaving a trail of gas and charged particles, the comet’s tail. The tail emanates from the head, or coma of the comet. The principal content of the comet is supposedly found in the nucleus of the coma. Note that the tail of charged particles has a different angle to the comet’s trajectory than the vapor cloud tail; forming two tails. This is different from an asteroid, which has no tail and consists of solids only. One of the more noted comets is Halley’s comet, last seen in 1986. Halley’s comet (initially Comet 1982i; renamed Comet 1986III) moves on its orbit around the Sun, traveling to the edges or our solar system, every 75–76 years, depending on our own position with respect to the observation in our orbit around the Sun. Another notable comet is Hale–Bopp (astronomy nomenclature: Comet C/1995 O1, “discovered” in 1995), which has been described dating back to millennia and has a period of 2537 years, and Hyakutake. So far a total of 10 comets have been identified in our solar system. The direction of the gas/vapor tail is indicative of the solar wind. Comets are considered to be essential constituents of the formation of our solar system; hence are bound to carry information about the history of the creation of the solar system (see Figure C.60).
Homotopy time-fractional enhancement soliton solution for six component complex cometary plasma with thermal heavy ions
Published in Waves in Random and Complex Media, 2023
Comets are important for understanding our solar system, e.g. its creation, and evolution, as well as the fundamental plasma processes at work both inside and outside of it. Cometary plasma systems are multi-ion plasma consisting of both lighter and heavier ions and electrons with different temperatures. When a comet’s nucleus is warmed by sunlight, it generates gas. The gas is ionized, produces plasma, and later interacts with the solar wind in the coma. If the comet's atmosphere is not that dense, solar wind proton ions striking the surface can directly influence the nucleus. Solar wind sputtering on the surface can produce elements such as C, O, Na, K, Si, Ca, and S, which are less volatile than the commonly released molecules H2O, CO, O2, and CO2 [1–3]. In general, cometary plasma systems are consisting of heavy positive and negative ions, hydrogen ions (proton), and electrons with relative densities, and these densities are depending on the distance from the nucleus [4–6].
Cooperative planning for multi-site asteroid visual coverage
Published in Advanced Robotics, 2021
Sumeet G. Satpute, Per Bodin, George Nikolakopoulos
Space missions to explore the small celestial bodies, like asteroids and comets, play a significant role in gaining more scientific insights on the origin of our solar system and life on Earth [1]. These missions, especially to the near Earth objects, i.e. celestial bodies, with perihelion distance smaller than (Astronomical Unit), are essential to advance the efforts to mitigate the hazard of possible asteroid impact with Earth by gaining information about the surface and material properties of the asteroid [2–4]. In addition, the emerging commercial economy for asteroid resource utilization of valuable resources, such as water, precious metals and minerals for the future inter-planetary missions [5,6], is strengthening the interest for enhancing existing asteroid visual coverage missions. For these reasons, during the past decade, various space agencies have conducted asteroid missions for studying, characterizing and sample collection of asteroids like the JAXA's Hayabusa I [7] and Hayabusa II [8] missions to the asteroids Itokawa and Ryugu, and NASA's OSIRIS-REx [9] to Bennu, ESA's Rosetta comet mission [10], and multiple other efforts in order to name a few. Moreover, several other missions are in the design and launch phase, like NASA's Double Asteroid Redirection Test (DART) mission [11] and ESA's Hera mission [12] both to Didymos system, JAXA's Demonstration and Experiment of Space Technology for INterplanetary voYage Phaethon fLyby dUSt science (DESTINY+) [13] and NASA's Phyche mission [14]. In addition to the governmental agencies, in recent years, several private companies are registering their interest in asteroid exploration missions like Beyond Atlas [15], Deep Space Industries and Planetary Resources [16]
Plasma Waves Around Comets
Published in IETE Technical Review, 2022
During its approach towards Sun, the comet sheds its material due to sublimation forming a vaporized gas cloud which becomes its tail, extended up to few AU, on the opposite side of the Sun due to the solar radiation pressure. The gas cloud of the comet comprises H2O, CO2, different hydrocarbons, and other volatile compounds. The plasma environment of a comet is essentially dominated by the interaction of newly generated ions with the incoming solar wind. The large scale features of the solar wind-comet interaction are shown in Figure 1 [57].