The MARS EXPRESS Limbs Observations Database.

46th Lunar and Planetary Science Conference (2015)
The MARS EXPRESS Limbs Observations Database.
B. Gondet1, J-P Bibring1, F. Montmessin2, F. Lefevre2, G. Lacombe2, M. Giuranna3, A. Aronica3, H. Hoffmann4,
and the Mars Express Science Ground Segment Team5, 1IAS batiment 121, 91405 Orsay Campus, France,
[email protected], 2 LATMOS CNRS/UVSQ/IPSL, 78280 Guyancourt, France, 3 INAF Istituto Nazionale di AstroFisica,
Via del Fosso del Cavaliere, 100-00133 Rome, Italy, 4 DLR, Institute of Planetary Research, Rutherfordstrasse 2, 12489 Berlin,
Germany, 5 European Space Agency, ESAC, Villanueva de la Canada, Spain
The capability to orient Mars Express makes it possible to implement a great diversity of observations
modes, in particular nadir and limb (fig 1). During day
and night limb’s observations, 4 out of 7 MEX instruments (the spectrometers: SPICAM[1], OMEGA [2],
PFS [3] and the high-resolution camera HRSC [4])
work together to provide spectra (.12 µm to 45 µm) of
the Martian atmosphere (dust and clouds detached
layers, day and night emissions), at each altitude step,
with the associated image.
Fig 2: detached layer observed by HRSC
Fig 1 : Mars Express pointing modes relevant for
limb observations by remote sensing instruments.
Until now, the data reduction of observations of the
limb from each Mars Express instrument had been
done separately. Examples of the potential of each data
set are given in Figures 2,3,4,5). We present here a
database which makes it possible to retrieve the limb
observations from different Mars Express instruments
relevant for a given location and time frame. The limb
database is now accessible to the scientific community
via the ESA/PSA website (
Fig 3: image (left) and spectrum (right) of a dust detached layer (~ 40 kms) observed over the Hellas basin
by OMEGA (Ls: 310°, local time: 18h). Two major
emission lines are observed at 3.2 µm (H2O ice) and
4.7 µm (CO)
46th Lunar and Planetary Science Conference (2015)
tific results, JGR vol 111 , 2006 ; [2] Bibring, J.P. ., et
al., OMEGA: Observatoire pour la Minéralogie, l’Eau,
les Glaces et l’Activité, ESA SP 1240, 37-49, 2004a ;
[3] Formisano, V. et al, PFS onboard theEuropean
Mars Express Mission PSS 40, 963-974, 2005 ; [4]
Neukum, G. et al HRSC: The High Resolution Stereo
Camera of Mars Express ESA SP 1240, 2004b
Fig 4: a synthesis of SPICAM data showing the prominent southern polar ozone layer around 50km
Fig 5: An average of about 3000 PFS limb
spectra, selected during the fall season (180°
< Ls < 270°), in the southern hemisphere
(latitude < 0°), and for tangent altitudes between 50 and 200 km. Several emission bands
can be easily identified in the spectrum. FB,
FH, SH, TH, and FRH mean fundamental,
first hot, third hot, and fourth hot bands, respectively. The small top-left panel shows the
CO emission spectrum at 4.7 μm for the same
average. The gray curve is the Planck radiation at 280 K.
The cross-linking of observations of clouds and detached dust layers in the Martian atmosphere at different wavelengths as provided by the “limbs” database
in the ESA Mex archive should constitute a useful
reference for interpreting each data set and modeling
processes in the upper atmosphere of Mars.
Reference: [1] Bertaux, J.L. ., et al., SPICAM: Observing modes and overview of UV spectrometer data and scien-