1. Space Physics at Mars Paul Withers 2006.03.13 Journal Club Research Talk Center for Space Physics, Boston University Aims: Show students how principles of space physics apply at Mars Emphasize wide range of interesting phenomena Stimulate interest in Mars-related research projects

2. Same Physics, Different Place Interaction of solar wind and magnetic field Aurora Ionospheric physics –Solar flares –Meteors –Plasma instabilities and currents Observations –Magnetometers and charged particle detectors –Thousands of Ne(h) profiles –Topside ionospheric sounder

3. Magnetic Field What happens when the strength of the magnetic field varies over horizontal distances of 100 km? What happens when there are multiple cusps close to multiple equators? Expect lots of inhomogeneities Longitude and local time matter, not just local time

4. Aurora have been seen (once) on Mars Electron data suggest they occur often What are the effects of martian atmospheric chemistry? Aurora

5. Ionospheric Profiles Earth (Hargreaves, 1992) F layer due to EUV photons E layer due to soft X-rays D layer due to hard X-rays (Over-simplification...) Mars (MGS RS data) Main peak at 150 km due to EUV photons Lower peak at 110 km due to X-rays Lower peak is very variable, often absent

6. How might flares affect GPS or communications? Do terrestrial empirical models of secondary ionization work at Mars? Can response of neutral atmosphere and ionosphere to changes in solar flux be decoupled? Mendillo et al., Science, 24 Feb 2006

7. Meteors Does Mars have seasonal meteor showers? If so, what are the sources? Does Mars ever experience massive meteor storms? How do meteors affect atmospheric chemistry? What can we learn about the atmospheric structure from these test particles?

8. What ionospheric irregularities and instabilities are present? Equatorial spread-F? Equatorial electrojet? What is the equivalent of the dynamo current system? Can ionospheric currents induce magnetic fields as large as the planet’s internal field? Weird Stuff

9. Available Observations and Models Thousands of Ne(h) profiles New topside ionospheric sounder (MARSIS) Particles and fields measurements 1-D model of ionospheric photochemistry and diffusion MHD models for Mars environment exist Apply CISM tools to Mars?

10. http://science.nasa.gov/ssl/pad/sppb/edu/magnetosphere/images/mag_sketch.gif http://www.windows.ucar.edu/earth/images/earth_magneto.jpg http://mgs-mager.gsfc.nasa.gov/publications/grl_28_connerney/grl_28_connerney_fig1.html http://www.nature.com/nature/journal/v435/n7043/images/nature03603-f1.2.jpg http://www.spaceweather.com/aurora/images/31mar01/haug1.jpg http://sirius.bu.edu/data/flare_effect_jpg.jpg Sources of images