Dust Storm- Opportunity EOM, the end of the beginning of a new era in robotic spaceflight Options

[Deimos]

It's all good, until you look at more than one clock. The tau site has a reasonably accurate clock, just checked against NAIF. If you change '-b' to '-a' or '-c' in the URL, the clocks are off by several seconds due to lack of leap second correction, and maybe due to precision issues for Spirit. The Opportunity version seems to agree with the dmuller.net link to <10 sec, too.

[mcaplinger]

Opportunity is at the opposite side of the planet from Spirit, so the LST times should be around 12 hours apart.

Maybe overkill, but I use https://www.giss.nasa.gov/tools/mars24/ -- right now it says it's 11:24 at Meridiani and 01:14 at Gale, which sounds about right.

[Phil Stooke]

So, if we can just get Spirit to Gale everything will fit.

Phil

[mcaplinger]

So, if we can just get Spirit to Gale everything will fit.

Pedantic much? They're at about the same longitude and who cares what time it is at Gusev? [Well, in fairness, they're not that close -- Mars24J says there's about 2 hours different between Gale and Gusev. If it's right.]

[mcaplinger]

Perhaps the article linked above is confusing mm with microns (mu-m).

I'm going to blame either Deimos or bad typesetting at Science for this -- in http://science.sciencemag.org/content/306/5702/1753 the abstract says "The dust's cross section weighted mean radius was 1.47 ± 0.21 micrometers (mm) at Gusev and 1.52 ± 0.18 mm at Meridiani." "mm" is, as far as I know, not a valid SI abbreviation for micrometer, which is mu-m. https://en.wikipedia.org/wiki/Micrometre

[Phil Stooke]

Pedantic, moi?

You're right of course, I was pedantic! It was a slow morning... but the discussion arose out of this recent post:

-------------------------------------------------------------
marsophile: (post 130 above)

https://mars.nasa.gov/mer/home/

QUOTE
Opportunity at Meridiani
Sol: 5127 Time: 12:51

Spirit at Gusev
Sol: 5148 Time: 14:18

This doesn't seem right---Opportunity is at the opposite side of the planet from Spirit, so the LST times should be around 12 hours apart. Having the correct local time for Oppy is useful for checking the DSN Now comm schedule.
--------------------------------------------------------------

So it really did concern Gusev, not Gale.

However, I will try not to give in to temptation in future, unless it's a really big juicy temptation.

Phil

[PaulH51]

MRO MARCI Weather report for the week of 18 June 2018 – 24 June 2018. Published June 28, 2018.

http://www.msss.com/msss_images/2018/06/27/

[serpens]

"mm" is, as far as I know, not a valid SI abbreviation for micrometer, which is mu-m. https://en.wikipedia.org/wiki/Micrometre

I was always taught that the symbol for a micron or micrometre is μm. In fact the link confirms this and the SI spelling convention, although I appreciate that this is one of the words where US spelling deviates. Personally I feel that errors in nomenclature or symbols should be considered more than just a passing annoyance given the fate of the Mars Climate Orbiter.

[nprev]

[ADMIN MODE]...and on that note we're done with the abbreviation debate, or 'abd'. Moving on...

[marsophile]

https://mars.nasa.gov/mer/mission/status_spiritAll_2008.html
It could be said that the great dust storm of 2007 indirectly led to the loss of Spirit in 2010. As the sky cleared, dust falling on the solar panels forced Spirit to seek an extreme slope of 25 degrees at "Winter Haven 3" on the northern edge of Home Plate for the subsequent Martian winter. When spring came, Spirit was unable to climb back onto Home Plate, which caused it to take an alternative route below, which ultimately proved fatal.
To ensure a similar fate does not befall Opportunity. it may be worthwhile to seek immediate cleaning of the solar panels in the aftermath of the storm. Perhaps observing wind trails in the new dust deposits would provide information about the current wind regime at Perseverance so that Oppy could position itself where cleaning is most likely in the months before the coming of winter. It is true, though, that Opportunity is closer to the equator so maybe, hopefully, that will not be an issue.

[djellison]

Opportunity experienced a major cleaning event in Perseverance Valley at the end of 2017. The rover couldn't be in a better place to get cleaned than it is now.

[marsophile]

http://www.spaceflightinsider.com/space-fl...ian-dust-storm/

July 1 update.

[marsophile]

http://www.planetary.org/explore/space-top...dust-cloud.html
The monthly MER update.

This might be a good theme song for Oppy under current circumstances:
https://www.youtube.com/watch?v=gYkACVDFmeg
"I Will Survive"

[scalbers]

Here is an updated simulation with Tau ranging from 0.5 to 11.0 in 0.5 steps. This shows the reversal to a darker horizon somewhat better. The software roughly estimates solar horizontal irradiance, ranging from 360 W/m^2 down to 13.5 W/m^2. The solar elevation angle is 45 degrees.





I'll consider adding a strip of land at the bottom next. Below is a table of the estimated global horizontal irradiance.

Tau GHI (W/m^2)
--- -----------
0.5 360.4
1.0 311.3
2.0 230.6
3.0 169.7
4.0 124.4
5.0 90.9
6.0 66.2
7.0 48.2
8.0 35.1
9.0 25.5
10.0 18.5
11.0 13.5

[JRehling]

I had some excellent terrestrial weather last night for observing the Opportunity site which still has terrible martian weather. Meridiani is near the left side of the disc here, and the state of the dust storm is evident in the wispiness of the dark areas, including Syrtis Major at right. However, it's not quite a blank disc, which is a hopeful sign.

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