Distribution of hydrogen in the near surface of Mars: evidence for subsurface ice deposits.
Using the Gamma-Ray Spectrometer on the Mars Odyssey, we have identified two regions near the poles that are enriched in hydrogen. The data indicate the presence of a subsurface layer enriched in hydrogen overlain by a hydrogen-poor layer. The thickness of the upper layer decreases with decreasing distance to the pole, ranging from a column density of about 150 grams per square centimeter at -42 degrees latitude to about 40 grams per square centimeter at -77 degrees. The hydrogen-rich regions correlate with regions of predicted ice stability. We suggest that the host of the hydrogen in the subsurface layer is ice, which constitutes 35 +/- 15% of the layer by weight.
Boynton
W V
WV
Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA. wboynton@lpl.arizona.edu
Feldman
W C
WC
Squyres
S W
SW
Prettyman
T H
TH
Bruckner
J
J
Evans
L G
LG
Reedy
R C
RC
Starr
R
R
Arnold
J R
JR
Drake
D M
DM
Englert
P A J
PA
Metzger
A E
AE
Mitrofanov
Igor
I
Trombka
J I
JI
D'Uston
C
C
Wanke
H
H
Gasnault
O
O
Hamara
D K
DK
Janes
D M
DM
Marcialis
R L
RL
Maurice
S
S
Mikheeva
I
I
Taylor
G J
GJ
Tokar
R
R
Shinohara
C
C
D001272:Atmosphere; D004367:Dry Ice; D005118:Extraterrestrial Environment; D005720:Gamma Rays; D006859:Hydrogen; D007053:Ice; D018535:Mars; D008962:Models, Theoretical; D009502:Neutrons; D018531:Spacecraft; D013051:Spectrometry, Gamma; D013057:Spectrum Analysis; D014867:Water
D004367:Dry Ice; D007053:Ice; D014867:Water; D006859:Hydrogen