MESSENGER MASCS M1 Flyby Preliminary Results. MASCS Flyby Trajectories Courtesy Killen et al. 2008 LPSC Abstract.

MESSENGER MASCS

M1 Flyby Preliminary Results

MASCS Flyby Trajectories

Courtesy Killen et al. 2008 LPSC Abstract

TailsweepH, Na

spacecraft (S/C)time shown

~1 min

S, Na

H,O,O,Ca,K,Na

S, Ca, K, Na

MASCS at M1

Courtesy Killen et al. 2008 LPSC Abstract

Preliminary Results

• H, Na, and Ca observed• S and K not observed• First high spatial resolution observations of the Na tail

emission• First detection of the H tail emission• First time H and Na observed in the tail simultaneously• Ca detected in near-Mercury atmosphere• Spatial asymmetries seen in the Na and H emission –

confirms ground-based measurements of asymmetry• Killen et al. collected ground-based observations of the Na

emission from Kitt Peak’s McMath-Pierce Solar telescope during the flyby

Color Scale: 0 – 40 KRayleighs

Color Scale: 100 – 400 Rayleighs