1. Mercury’s Sodium Tail McDonald Observatory “Narrow Field” 2007-8

2. Scale: 8 arc-seconds per fiber 1-2 minute exposures Calibrated with standard stars 2007: –May 28-30, June 2 –Nov. 13 2008: –Jan. 13, 15-17 16” Meade + Image-Slicer Spectrograph: Observing parameters

3. Example of Raw Data Mercury’s Disk Terrestrial Na Mercury Na

4. May 30, 2007 (V R =9.4 km/s away)

5. November 13, 2007 (V R =9.4 km/s away)

6. January 16, 2008 (MESSENGER Flyby V R =9.5 km/s towards)

7. Summary May 30,2007 January 16, 2008 November 13, 2007