GROUND BASED AND MESSENGER OBSERVATIONS OF MERCURY’S

EXOSPHERE

The Bepi-Colombo-MESSENGER Serena Workshop

Key Largo, Florida, May 14-16, 2013

Rosemary Killen&

The MASCS Team & Andrew Potter, Thomas Bida, Kevin Reardon

The Na D line

Mercury Na Exosphere during transit of 2006, Dunn Solar TelescopePotter, Killen, Bida, Reardon

Na exosphere Transit 2003Schleicher et al.

Na Jan.08

Na Observed from Kitt PeakPotter & Killen

Sodium ExosphereMoon and Mercury

Sodium Tail from Kitt Peak

Potassium Emission

Na/K Map

Abundance of Potassium in RocksPatrick N. Peplowski, Larry G. Evans

Abundance of Na in Rocks

Corrected Na Emission vs. TAA

Keck Observations Na June 9, 2000

Mercury Ca 9 June 2000

Ca May 3, 2002

Ca June 27, 2005

Ca May 15 2008

Summary• Na/K shows N enhancement in the exosphere– but K is more enhanced in the rock at N than Na

•Na scale height is lower over the polar regions than equatorial regions indicative of lower temperature

-but this does not seem to be the case in MESSENGER data•Na occasionally shows high latitude enhancements but not always•Na sometimes shows dawn enhancements but not always•We saw no dawn enhancement in 2006: TAA 330•Ca appears to be in a wide corona as seen from dawn or dusk