Methane on Mars: PFS and VLT, Keck, IRTF, SUBARU joint observations campaigns
Abstract
During April and May 2012 the Planetary Fourier Spectrometer (PFS) onboard Mars Express (MEx) performed a series of observations of Mars' atmosphere in combination with the campaigns of four important ground-based telescopes: CRIRESVLT, NIRSPEC-Keck2, HIPWAC-IRTF, and IRCSSUBARU. VLT is located in Paranal (Chile). Keck, SUBARU, and IRTF are located in Mauna Kea (Hawaii). This is the first time that simultaneous ground-based and remote-sensing observations of Martian atmosphere have been performed. The final aim is to verify CH4 on Mars, constrain its source, and investigate the distribution of H2O/HDO ratio. Moreover, the intercomparison of these analyses is of extreme importance for it will help us to understand the reason for the discrepancies among the results of various groups previously reported, and validate the various retrieval methods involved in the analyses. The areas of most interest for Methane have been targeted in the various campaigns. The observations cover different areas of possible sources of CH4, such as the areas where the extend plumes of CH4 were detected by previous ground-based and PFS/MEx observations [1,2] and suggested potential mud volcanism areas [3,4]. An example of PFS and SUBARU joint observations is shown in Figure 1. The map shows the region of Mars observed by IRCS on April 13th, from 05:00 to 12:00 UTC. Acidalia Planitia [30-60°N, 300-360°E] Terra Sabae [30S-30°N 300-330°W] and the North pole have been observed in early summer (Ls = 96°). PFS tracks of observations (yellow) are also shown in Figure 1 for the time period 10-17 April (cyan is for actual simultaneous observations). Proper retrieval of methane abundance with PFS requires several observations to be averaged in order to get sufficient SNR. If necessary, simultaneous and "quasi-simultaneous" (+/- 3 days) observations may be averaged together. Sub-Earth and Sub-Solar points are also shown in Figure 1 for April 13th, 7:00 am UTC (blue and yellow circles, respectively). We will describe in details the joint observations campaigns and report available preliminary results.
- Publication:
-
European Planetary Science Congress 2012
- Pub Date:
- September 2012
- Bibcode:
- 2012epsc.conf..689G