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[Exo]Planetary Atmospheres

Atmospheric Modeling

Here is a top-down illustration of the satellite’s sunlit leading & trailing hemispheres orbiting in the Io-plasma torus with the three external influences highlighted. Red vectors = the O2 source (sputtering). Yellow vectors = the solar radiation, fixed at the bottom of the page. Blue vector = the revolution around Jupiter. The above geometry of the three external influences results in a 'Rotation-Driven exosphere." The molecular oxygen components of Europa and Ganymede's exospheres are thought to be rotation-driven. On these two satellites, the result of this rotation is a large atmospheric bulge near dusk, local time.

Atmospheric Observations

The Galilean satellites present excellent testbeds to understand the behavior of a tidally-locked atmosphere, that is an atmosphere on a tidally-locked body. These bodies are common place in exoplanet observations, where in the above illustration, the primary body is of course a star. These extreme environments deserve focused observational searches in order to characterize their atmospheres.

Atmospheric Technology

While we wait for our simulations to converge, and our observations to be taken, I am in our space instrumentation laboratory, LATMOS, where we are developing an application for a sensitive exosphere instrument using nanotechnology. Pictured above is our Carbon Nanotube Electron Gun (CNTeg) which is capable of emitting a stable current of 100 microAmps with less than 10 milliwatts of power.

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