Dust Storm Season |
Dust Storm Season |
Jun 15 2005, 02:40 AM
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#1
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
Given Steve Squyres consern for the upcoming dust storm season:
QUOTE (Steve Squyres) And in the "it's always something" department... we are now facing a new threat to both vehicles. It is dust storm season on Mars. Dust storm season happens once per martian year, during the southern summer when the input of solar energy into the martian atmosphere is highest. And southern summer is now upon us. The atmospheric dust levels at both of our landing sites are high and climbing, and in fact the dust level at the Opportunity site is the highest we've ever encountered. It's not a serious threat yet, but it's a worry, and we're watching the dust levels in the atmosphere very closely. The thing to realize about dust storms is that the threat is not high winds, nor is the primary threat dust buildup on the solar arrays. Instead, the primary threat is simply the attenuation of sunlight by dust that is suspended very high in the atmosphere, and the resultant loss of power from our solar arrays. RIght now we've got power to spare on both vehicles, and there is no imminent danger. But martian dust storms are notoriously hard to predict. In some years things are pretty quiet, and in other years what starts out as a small regional storm can blow up quickly into a monster that covers the whole planet, with solar attenuation that could be very bad for our vehicles. We have no way of knowing what's going to happen this year. I think a thread about the possible effects is in order... This page has some good info of the dust storm seasons. The peak season this year runs from July 01, 2005 (241° Ls) to August 16, 2005 (270° Ls). The good news is big bad 'global' storms are very rare so hopfully they won't be a problem anyway. (fingers crossed) Steve mentioned that it is the loss of solar power due to the high levels of dust in the atmosphere that is the problem. I searched around for more info about how bad it could get and found this with regard to Sojourner: QUOTE a) Available panel power, any time during a clear-day (tau = 0.5) 6 hour period (20° N, untilted) exceeds ~11 W ( ~14.9 W at mid-day). This power could be attenuated by approximately a factor of two during severe dust storms (optical depth ~4, the worst that Viking experienced). A factor of two loss of power wouldn't be good but that shouldn't be much worse than what Spriit had before her cleaning event, so should be survivable. I think we'll have to be very unlucky to loose either rover to dust storms in the near future. I hope I'm right! James -------------------- |
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Jun 15 2005, 02:49 AM
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#2
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Member Group: Members Posts: 578 Joined: 5-November 04 From: Denmark Member No.: 107 |
Latest flight director report also has something about Opportunity recording the highest tau value yet.
http://www.jpl.nasa.gov/missions/mer/flightdir.cfm But still no power numbers... I would really like an update to see were we are right now -------------------- "I want to make as many people as possible feel like they are part of this adventure. We are going to give everybody a sense of what exploring the surface of another world is really like"
- Steven Squyres |
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Jun 15 2005, 06:16 AM
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#3
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The Insider Group: Members Posts: 669 Joined: 3-May 04 Member No.: 73 |
I think Oppy is hovering somewhere in the low-to-mid 400Whr range in the past few sols...
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Jun 15 2005, 06:52 AM
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#4
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
QUOTE (Pando @ Jun 15 2005, 04:16 PM) Any idea how much of that is due to atmospheric dust as opposed to dust on the panels? i.e what was the power output the last time tau was low? Thanks, James -------------------- |
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Jun 15 2005, 07:40 AM
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#5
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The Insider Group: Members Posts: 669 Joined: 3-May 04 Member No.: 73 |
The power levels were around 600Whr range before the dust storms started to kick in, two weeks ago or thereabouts. So yes, much of it is due to dust in the atmosphere.
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Jun 15 2005, 07:59 AM
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#6
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Senior Member Group: Members Posts: 1870 Joined: 20-February 05 Member No.: 174 |
Dust storm season can run from roughly before mid southern spring to past mid summer. Some years have no global or globe-encercling storm. The Viking landers first winter on mars <soutnern summer> was hit by two globe-encircling storms.
Good views of "dust storm season" on Mars from Earth occur near perihelic oppositions: basically 2 or 3 oppositions, followed by some 5 oppositions closer to aphelion, the whole cycle taking very roughly 20 years. There was a major storm in '56, I don't recall adjacent oppositions, then in 71 the greatest ever, and a major one in 73. Probably not in 75 (before Vikings landed). 2 Storms in 77 (minimally observable from Earth, but observed from ground and orbit by the Viknigs), none the next Mars year (according to Viking 1) and there was a major storm (at least locally) as Viking 1 died from battery failure and command error the year after that. During the perihelic oppositions in the 80's, I think the surprise was no major storms, and that prompted searches to see if there were other storm-free periods as seen from earth in the historical record, which I think was more confusing then informative, due to the spotty periodic occurrences of perihelic oppositions. It's very very unclear, at least from my memory, if there's any consensus on whether storms are random from one year to the next, or occur in clusters with a tendency for several mars years in a row to be storm-free. |
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Jun 15 2005, 11:55 AM
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#7
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Member Group: Members Posts: 378 Joined: 21-April 05 From: Portugal Member No.: 347 |
I does look as Mars is getting an atmosphere
http://marsrovers.jpl.nasa.gov/gallery/all...0P2428L7M1.HTML http://marsrovers.jpl.nasa.gov/gallery/all...0P2428R1M1.HTML It really looks like a different place, less alien, more earth like. But also more rover unfriendly! -------------------- _______________________
www.astrosurf.com/nunes |
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Jun 15 2005, 12:10 PM
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#8
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Member Group: Members Posts: 249 Joined: 11-June 05 From: Finland (62°14′N 25°44′E) Member No.: 408 |
I was hoping to see a good view of the Gusev crater rim from the top of the Columbia Hills. No hope for that anymore.
-------------------- The universe is not only stranger than we imagine, it is stranger than we can imagine.
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Jun 15 2005, 02:47 PM
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#9
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
I see no other no alternative to keep the power up unless Oppys sleeps more often. The next missions to Mars must not depend upon to the light power but another sort of source of energy. I was imaging if the Oppys has own very efficient light that can feed more energy than it consumes and helps to keep battery up all round year.
Rodolfo |
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Jun 15 2005, 03:59 PM
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#10
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Senior Member Group: Members Posts: 1887 Joined: 20-November 04 From: Iowa Member No.: 110 |
Interesting bright streaks where Oppy's front wheels were parked. They look like wind blown streaks. |
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Jun 15 2005, 04:37 PM
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#11
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Member Group: Members Posts: 578 Joined: 5-November 04 From: Denmark Member No.: 107 |
QUOTE (RNeuhaus @ Jun 15 2005, 02:47 PM) I see no other no alternative to keep the power up unless Oppys sleeps more often. The next missions to Mars must not depend upon to the light power but another sort of source of energy. I was imaging if the Oppys has own very efficient light that can feed more energy than it consumes and helps to keep battery up all round year. So you want to make a device that produces more power than it consumes? Good luck with that Before we can do that the good news is that MSL will use RTG power so sunlight and dust storms will not be a problem -------------------- "I want to make as many people as possible feel like they are part of this adventure. We are going to give everybody a sense of what exploring the surface of another world is really like"
- Steven Squyres |
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Jun 15 2005, 04:50 PM
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#12
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
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Jun 15 2005, 05:17 PM
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#13
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
QUOTE (dot.dk @ Jun 15 2005, 11:37 AM) Why is it a problem? -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Jun 15 2005, 05:36 PM
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#14
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Solar System Cartographer Group: Members Posts: 10226 Joined: 5-April 05 From: Canada Member No.: 227 |
It sounds crazy, but it just might work...
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PDF: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Jun 15 2005, 06:08 PM
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#15
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Junior Member Group: Members Posts: 67 Joined: 18-April 05 From: Austin, Texas Member No.: 249 |
Has anyone noticed the black circle in the sand located at about five o'clock within the navcam photo posted today in exploratorium http://qt.exploratorium.edu/mars/opportuni...V4P1914L0M1.JPG? I have tried to include the photo in this post, but am not sure I succeeded. Any ideas what it is? It does not appear to be a mini-crater -- almost as if Oppy parked there over night and dripped oil |
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