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MSL scientific results
HughFromAlice
post May 30 2013, 12:45 PM
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Been busy with other things for a while, so it's nice to be back and see all the photo imaging work on the site going from strength to strength rolleyes.gif

I think a lot of you guys would really enjoy "Curiosity On Mars:First Results" 3 part x approx 2 hr presentations at the EuroGeosciences Union General Assembly published on the EGU Channel on YouTube on May16th. Plenty of good listening for the weekend! Although I enjoy the NASA press briefings, it's great to hear key mission scientists talking full-on to their peers. The talks travel along at a nice fast thought provoking pace!

http://www.youtube.com/watch?v=hPbbhfGg0nc

Admin: Moved post from 'First Drill' thread.
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Paolo
post May 30 2013, 06:06 PM
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at long last, the first two peer-reviewed papers on Curiosity's scientific results!

Martian Fluvial Conglomerates at Gale Crater
Measurements of Energetic Particle Radiation in Transit to Mars on the Mars Science Laboratory
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nprev
post May 31 2013, 07:43 AM
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0.66 Sv +/- 0.12...ouch. Not good. unsure.gif


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imipak
post May 31 2013, 10:53 PM
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A story by Jonathon Amos on the BBC news site about the Fluvial Conglomerates paper, with a great interview with Sanjeev Gupta:
http://www.bbc.co.uk/news/science-environment-22708902


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Jimbo1955
post Jun 2 2013, 12:58 AM
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QUOTE (nprev @ May 31 2013, 02:43 AM) *
0.66 Sv +/- 0.12...ouch. Not good. unsure.gif


About what the highest dose received by a Fukashima worker obtained.
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dvandorn
post Jun 2 2013, 01:36 AM
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MSL's cruise phase took place as the Sun was ramping up to an activity peak in its 11-year cycle. And as I recall, we've seen a somewhat unusually active ramp-up this time around. Perhaps radiation-sensitive payloads may have to take advantage of transfer orbit windows that occur during quiet sun periods?

-the other Doug


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mcaplinger
post Jun 2 2013, 03:14 AM
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QUOTE (dvandorn @ Jun 1 2013, 06:36 PM) *
Perhaps radiation-sensitive payloads may have to take advantage of transfer orbit windows that occur during quiet sun periods?

The paper says that only about 5% of the total dose MSL saw in cruise was from solar events, the rest being from galactic cosmic rays. GCR dose rate is thought to be weakly anticorrelated with the solar cycle.

They do point out that "the SEP contribution could conceivably be many times larger in a different time frame" (i.e., closer to solar max.)


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atomoid
post Jun 4 2013, 01:35 AM
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not to get too OT here, but here's some interesting info on the topic and additional flashes of inspiration
"..The computers recover with a reboot; the cameras suffer permanent damage. After about a year, the images they produce look like they are covered with electronic snow.."
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Gerald
post Jun 4 2013, 09:38 AM
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Those flashes are mostly caused by Cerenkov radiation, when charged particles move faster than light moves in the same medium (phase velocity), however slower than vacuum speed of light, of course. (Light moves slower in most media than in vacuum; speed of light is dependend of wavelength in media.)

The main challenge associated with high-energy cosmic rays isn't the Cerenkov radiation, but a cascade of particle-antiparticle pair production resp. (hadronic) showers of secondary particles.
Therefore a shielding can multiply the radiation caused by a GCR hit.
The resulting question is, how to design a shielding that reduces solar energetic particles (SEP), and doesn't multiply GCR-induced secondary radiation too much.
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Gerald
post Jun 4 2013, 10:48 AM
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... one idea to circumvent this dilemma is a dynamic shielding, because most of SEP radiation occurs in peaks: SEP graphics in JPL Photojournal.
Thin shielding during low SEP activity to avoid secondary particles caused by GCRs; thick shielding during SEP peaks, detected by instruments, or presumed by forecast.

That's a transfere of the answer given in the recent telecon 0:47:09 to 0:49:16 to robotic missions.
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Paolo
post Jul 18 2013, 06:33 PM
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another batch of MSL results in Science
Isotope Ratios of H, C, and O in CO2 and H2O of the Martian Atmosphere
Abundance and Isotopic Composition of Gases in the Martian Atmosphere from the Curiosity Rover
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Marz
post Sep 7 2013, 11:39 PM
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fyi: The upcoming Geological Society of America's annual meeting has a few sessions dedicated to MSL:

T1. CURIOSITY AT GALE—PAST AND PRESENT ENVIRONMENTS OF MARS

LATE JURASSIC ROCKS OF THE COLORADO PLATEAU AS DEPOSITIONAL AND DIAGENETIC ANALOGS TO GALE CRATER, MARS

There's also a session on Mercury, Icy Worlds, Lunar Water, and comparison of Saharan and Mars dunes.
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Don1
post Sep 14 2013, 08:20 PM
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QUOTE (Marz @ Sep 7 2013, 04:39 PM) *

I skimmed through the abstracts. Here are some quotes.

* "fluvio-lacustrine sedimentary rocks (showing some signs of volcanic influence), known as Yellowknife Bay formation, which could be as young as middle Hesperian to even early Amazonian."

* " a habitable subaqueous sedimentary environment that persisted from 100’s yrs to 10’s Kyrs. "

* " influence of at least two generations of fluids."

* "Curiosity has observed abundant evidence of geologically recent surface modification at the Gale crater landing site"

* "The flagstone-type fracture pattern, mudstone lithology, presence of swelling clay, and occurrence in a dominantly sedimentary sequence suggest that the polygonal fracture pattern of the Glenelg Regionare formed by desiccation in a drying playa...A possible change in climate resulted in drying of the lake, exposure of mudstones, and formation of desiccation cracks. "

* "ET-THEN: A POSSIBLE MARTIAN MAGMA?"

* " these data suggest late occurring, local alluvial activity on some fans...the timing of possible late alluvial activity in Gale correlates with alluvial activity in Margaritifer Terra hypothesized to result from melting snow...water would have drained downslope and could have contributed to development of late diagenetic features observed by Curiosity in the rocks at Yellowknife Bay."

* "The Yellowknife Bay formation has been split into four members (from base to top): the Sheepbed, Gillespie Lake, Point Lake, and Shaler members. The clay-bearing mudstones of the basal Sheepbed member suggest suspension settling in a distal alluvial or proximal lacustrine setting. A sharp contact traceable in orbital images for hundreds of meters separates the Sheepbed member from the Gillespie Lake member. The Gillespie Lake member consists of sheet-like beds of poorly sorted medium- to coarse-grained sandstone. The lateral continuity of these beds and the lack of channel bodies in the Gillespie Lake member indicate deposition in distal fan lobes. Overlying the Gillespie Lake member is the Point Lake member, characterized primarily by the presence of centimeter-scale vugs. Both volcanic and sedimentary interpretations are being considered for this enigmatic member. The overlying Shaler member consists of coarse-grained trough cross-bedded sandstone and pebble beds and recessive finer-grained intervals consistent with a fluvial environment dominated by bedload and suspended load transport. A set of diagenetic features observed throughout the Yellowknife Bay section suggests a complex aqueous history involving multiple phases of alteration. "

* "they also contain late diagenetic calcium-sulfate filled fractures that relate to their burial history... hydraulic fractures in YB mudstones attest to substantial burial and vertical movement of evolved brines from underlying or laterally adjacent strata."
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CosmicRocker
post Sep 15 2013, 01:47 AM
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Thanks for the nice summary.


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Den
post Sep 15 2013, 11:25 AM
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QUOTE (nprev @ May 31 2013, 08:43 AM) *
0.66 Sv +/- 0.12...ouch. Not good. unsure.gif


According to en.wikipedia.org/wiki/Background_radiation, average exposure in USA is 0.006 Sv/yr. There are several inhabited places on Earth with ~100 times more natural background - making 0.66 Sv/yr not as "ouch" as it looks at the first glance.
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