Sökning: "Comets"

Visar resultat 11 - 15 av 20 avhandlingar innehållade ordet Comets.

1. 11. 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

3. 12. Formation of small molecules in space through the process of radiative association

   Författare :Daria Jones; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astrochemistry; reaction rate constants; formation of molecules; physical chemistry;

   Sammanfattning : This thesis is dedicated to calculating the reaction rate constants for the formation of molecules through radiative association (RA) under interstellar conditions. The molecules that have been studied are CH, AlCl, Na+ − H2 and Al+ − H2. LÄS MER

4. 13. Quantum Chemical Exploration of Nitriles in Prebiotic Chemistry and Astrobiology

   Författare :Hilda Sandström; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; metadynamics; astrochemistry; iminoacetonitrile; hydrogen cyanide; acrylonitrile; azotosome; Titan;

   Sammanfattning : The Universe hosts countless different chemical environments, such as planets, moons, comets and the interstellar medium. The diverse pressures, temperatures and chemical compositions of these environments make a wide variety of processes possible. LÄS MER

5. 14. Nitriles in Prebiotic Chemistry and Astrobiology

   Författare :Hilda Sandström; Chalmers tekniska högskola; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; astrobiology; polymer chemistry; hydrogen cyanide; density functional theory; molecular dynamics; metadynamics; umbrella sampling; prebiotic chemistry;

   Sammanfattning : Life appeared on Earth within a billion years of the planet’s formation. How? - no one knows. Theories regarding the origin of life involve reactions of molecules predicted to have existed on early Earth in what is called prebiotic chemistry. LÄS MER

7. 15. 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