Sökning: "Venus Express"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Venus Express.
1. Escape to space or return to venus : ion flows measured by venus express
Sammanfattning : The present-day Venusian atmosphere is crushingly dense, extremely hot and arid. Yet, in its early history, Venus presumably had a massive amount of water, which, if spread evenly over the surface, provided a water depth of 10s to 100s of meters. Therefore, over the course of the atmospheric evolution, the water must have been removed from Venus. LÄS MER
2. The Neutral Particle Detector on the Mars and Venus Express missions
Sammanfattning : The Neutral Particle Detector (NPD) is a new type of instrumentation for energetic neutral atom (ENA) diagnostics. This thesis deals with development of the NPD sensor designed as a part of the plasma and neutral particle packages ASPERA-3 and ASPERA-4 on board Mars Express and Venus Express, the European Space Agency (ESA) satellites to Mars and Venus, respectively. LÄS MER
3. The induced magnetospheres and magnetotails of Mars and Venus
Sammanfattning : In this work we focus on several aspects of the ionospheres, induced magnetospheres, and magnetotails of the unmagnetized planets Mars and Venus. The solar wind interaction with unmagnetized planets differs from the magnetized planets: they are more directly exposed to the solar wind, and consequently can respond faster and more dynamically to solar wind variations, necessitating careful analysis of the driving conditions upstream simultaneously with plasma measurements in the system. LÄS MER
4. Instrumentation for energetic Neutral atom measurements at Mars, Venus and The Earth
Sammanfattning : This thesis deals with the development and calibrations of sensors to measure energetic neutral atoms (ENAs) at Mars, Venus, and the Earth. ENAs are formed in charge exchange processes between energetic, singly--charged ions and a cold neutral gas. LÄS MER
5. Mars : plasma environment and surface hydrology
Sammanfattning : This doctoral thesis treats parts of the solar wind interaction with the Martian atmosphere and the water-related features known as gullies. The composition of the escaping plasma at Mars has been investigated in an analysis of data from the IMA sensor, which is a part of the ASPERA-3 instrument suit onboard the European satellite Mars Express. LÄS MER