Tuesday, March 24, 2015

Science from MAVEN, MOM

Key words: Mars Orbiter Mission, MOM, MAVEN, Mars Science results

I must confess that the trigger to write this post is NOT only due to the findings on Mars unfolded at the last week's 46th  LPSC conference (a. discovery of Martian aurora, b. finding dust particles at 90 km), but also a set of 2-papers published today at PNAS by the Curiosity team (supporting the existence of life on Mars). Unlike my earlier posts, most of the contents discussed here would be more on technical side. It has always been in my mind to bring out some expected science products from MAVEN and MOM. As I browsed through the abstracts listed on LPSC site (on a public domain); I went past both the sessions on Early results from MAVEN in a breeze, an exhilarating experience; while MOM had a solitary representation. Let us dig deep into the results (MAVEN-MOM).

MAVEN results (46th LPSC conference):
The two sessions of MAVEN at LPSC pretty much wrap up what is expected from MAVEN. I was awestruck at the performance of IUV-Spectrograph (discovery of Martian Aurora), congratulations......  McClintock/Nick Schnider (great heritage of C.A Barth @LASP). Lyman alpha lines of Hydrogen/Deuterium cleanly separated; along with a broad spectral range to pick, finally offering a luxury of imaging mode... this is awesome. To top it up, the IUVS is a WINNER to grab the image of Siding Spring nucleus, must say a life time opportunity. The mass spectrometer from GSFC, NGIMS has performed exceptionally well by measuring the neutral/ionic species in 150-400 km regimes. Paul Mahaffy's group holds the unique distinction of having their baby on Martian ground as well as on the orbiter. The solar electron/ion analyzers are bang on target in churning out very important data.  The discovery of dust particles at altitudes of 90 km too falls in the kitty of MAVEN. It will be interesting to hunt Helium (Ly-alpha) line 58.4 nm and the other high energy solar radiation by EUV spectrograph, which would give crucial inputs to the radiation budget estimations. Apologies for my ignorance on magnetic field, Langmuir probes.

MOM results Prediction mode:
11th August, 2015 : ISRO makes MOM data public on project proposal basis to Indian nationals, here is the : LINK

The technology demonstrator, MOM has already been out performing its expectations by clicking exceptionally good quality color images by virtue of its  1. Mars Color Camera (MCC) from its apogee (furthest, 76,000 km). Ms. Emily Lakdawalla, in her blog brought out an excellent comparison of MOM images with that of all the other taken in the past. She goes on to say in the same post that even the color images from MOM themselves will be a great success. There have been around a dozen images which are posted on facebook page of isromom. Few weeks ago, the 2. Methane Sensor for Mars (MSM) was showcased by posting a sample image taken near the Methane emission band; discussed in detail here on my post. MSM, basically is a Fabry-Perot etalon based differential radiometer which measures the columnar density of methane. As can safely be assumed that MSM is on its way to hunt down methane, the outcome of this wonder baby depends more on episodic nature of methane gas itself.

Credit: ISRO
This leaves, 3-more payloads to come up to the stage. 

3. MENCA (Mars Exospheric Neutral Composition Explorer) is a quadrupole mass spectrometer, an upgraded version of CHACE (CHandra's Altitudinal Composition Explorer) developed by our team in the Chandrayaan-I mission. It covers 1-300 amu with a resolution of one mass unit. As discussed in my earlier post here, MENCA has a huge potential to measure the neutral species in its ambiance (in-situ) by virtue of its unparalleled sensitivity of measuring gaseous partial pressures down to 10X(-14) torr. As the MAVEN's NGIMS has shown that the neutral species cease to exist above 400 kms; my plea to team-ISRO is please go for a DIP-DEEP mission (as MAVEN did) so that MENCA can skim the prevailing species below the present perigee point of ~400 km of MOM.

4. TIS  (Thermal Infra red Spectrometer): Keeping up the tradition of IR imaging spectrographs, ISRO has come up with a latest development for Mars mission, the TIS covers the 7-13 micron spectral region. The scientific goals of this instrument are:  i. estimate surface temperature, ii. mineral composition and iii. variability of aerosol/dust in Martian atmosphere. Though it falls under the heritage class; this payload has certainly jumped into a new spectral regime and hence an appropriate set of hardware. One can certainly look for a wealth of information on mineralogy and an extra bit on aerosol and dust.

5. LAP (Lyman Alpha Photometer): Team-ISRO has ventured into a new arena by developing a unique payload to measure the Lyman alpha line ratio of Hydrogen, Deuterium which would answer few questions on Martian atmospheric losses. LAP data would certainly have a lot to compare with that of IUVS, which has already brought a clean separation of H, D lines near 121.5 nm. The advantage LAP seems to be carrying is due to its technique of measuring the resonance absorption of H, D atoms by a specially selected solar blind PMT (Photomultiplier) which may offer an appreciable sensitivity to these measurements. Well... lets hope that LAP slips into a heritage class after this mission.

Hoping for an exciting time ahead when we have abundance amount of data from the  payloads of MAVEN and MOM.


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