Sökning: "Churyumov-Gerasimenko"

Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet Churyumov-Gerasimenko.

  1. 1. Low-energy ions around comet 67P/Churyumov-Gerasimenko

    Författare :Sofia Bergman; Gabriella Stenberg Wieser; Martin Wieser; Gert Brodin; Stein Håland; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Low-energy ions; spacecraft charging; comets; 67P Churyumov-Gerasimenko; Rosetta; RPC-ICA; SPIS; diamagnetic cavity; field of view; plasma; space plasma physics; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : Low-energy ions play important roles in the formation of the plasma environment around a comet. Reliable ways of measuring these ions are therefore of high importance to fully understand the processes and dynamics of this environment. Unfortunately, low-energy ions are infamously difficult to detect. LÄS MER

  3. 2. Plasma environment of an intermediately active comet : Evolution and dynamics observed by ESA's Rosetta spacecraft at 67P/Churyumov-Gerasimenko

    Författare :Elias Odelstad; Anders Eriksson; Andrew Coates; Uppsala universitet; []
    Nyckelord :Rosetta; comet; 67P; RPC-LAP; RPC-MIP; RPC-ICA; RPC-MAG; ROSINA-COPS; Langmuir probe; spacecraft potential; plasma; Churyumov-Gerasimenko; ion composition analyzer; diamagnetic cavity; ion velocity; electron temperature; ion-neutral drag; collisional coupling; wake effects; filamentation; electron cooling; plasma waves; hybrid waves; Bernstein waves; minimum variance; polarization; wavelet; density fluctuations; magnetic field oscillations; drift-cyclotron instability; asymmetric plasma and magnetic field enhancements; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : The subject of this thesis is the evolution and dynamics of the plasma environment of a moderately active comet before, during and after its closest approach to the Sun. For over 2 years in 2014-2016, the European Space Agency’s Rosetta spacecraft followed the comet 67P/Churyumov-Gerasimenko at distances typically between a few tens and a few hundred kilometers from the nucleus, the longest and closest inspection of a comet ever made. LÄS MER

  4. 3. Plasma Interactions with Icy Bodies in the Solar System

    Författare :Jesper Lindkvist; Mats Holmström; Martin Wieser; Elias Roussos; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; plasma interactions; icy bodies; solar system; space physics; plasma physics; hybrid model; numerical model; solar wind; magnetosphere; sub-Alfvénic; subsonic; non-collisional; atmosphereless; exosphere; coma; subsurface ocean; induction; magnetic dipole; pick-up ion; mass-loading; moon; natural satellite; dwarf planet; comet; Jupiter; Jovian; Callisto; Ceres; 67P; Churyumov-Gerasimenko; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : Here I study the “plasma interactions with icy bodies in the solar system”, that is, my quest to understand the fundamental processes that govern such interactions. By using numerical modelling combined with in situ observations, one can infer the internal structure of icy bodies and their plasma environments. LÄS MER

  5. 4. Solar Wind Dynamics within The Atmosphere of comet 67P/Churyumov-Gerasimenko

    Författare :Etienne Behar; Hans Nilsson; Thomas E. Cravens; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rymdteknik; Space Technology;

    Sammanfattning : In this thesis, we explore the dynamics of the solar wind as it perme-ates and flows through a tenuous cometary atmosphere, with a focuson the interaction observed at comet 67P/Churyumov–Gerasimenko.Seven comets had already been visited by nine different probes when the European spacecraft Rosetta reached comet Churyumov–Gerasimenko in August 2014. LÄS MER

  7. 5. Plasma and Dust around Icy Moon Enceladus and Comet 67P/Churyumov-Gerasimenko

    Författare :Ilka. A. D. Engelhardt; Anders Eriksson; Ingrid Mann; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : Saturn's moon Enceladus and comet 67P/Churyumov-Gerasimenko both are examples of icy solar system objects from which gas and dust flow into space. At both bodies, the gas becomes partly ionized and the dust grains get charged. LÄS MER