Huge Dust Storm on Mars.

silylene old · Jul 21, 2007

Jon, This equation is known as Beer's Law, or the Beer- Lambert Law. It does include both scattering and absorption, and as such expresses an effective attenuation in terms of tau (optical thickness). I have seen variations of the formula which separate out terms for absorption and scattering, but 'tau' seems to combine them together. Io is the incident light intensity in terms of energy / area on the outer atmosphere. I was happily suprised to see that Wikipedia has a very good description of this law and its derivation. Beer's Law <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

dragon04 · Jul 21, 2007

Certainly, if you dollar cost average the MER's based on their expected operational lifetime versus the actual lifetime to date, they've been the biggest bargain ever. As is the case with Voyager 1 and 2. That these systems are so robust is a testament to engineering and the highest standards of component and construction quality. <div class="Discussion_UserSignature"> "2012.. Year of the Dragon!! Get on the Dragon Wagon!". </div>

JonClarke · Jul 21, 2007

So if the recelved light is the incident light raised to the negative expotential of the tau value, it means that with a tau ofg 5 the rovers would be receiving 1/10,000 of the light a satellite in orbit would. That does not seem right. On earth you need tau values of about 12 to cause such extreme onscuration, like the black dust storms of Mongolia. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

robnissen · Jul 23, 2007

The dust storms appear to be abating (tau has dropped from 5 to 4), and the Little Rovers that Could, appear to be going strong: http://www.space.com/scienceastronomy/070723_rovers_update.html

3488 · Jul 23, 2007

Thanks RobNissen. That is truly very good news. Lets hope that the improvement continues & that dust does not coat the panels when it settles. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

arkady · Jul 24, 2007

Excellent news indeed. Disaster turned to opportunity. Certainly this must be the most well documented storm on Mars yet. <div class="Discussion_UserSignature"> "The choice is the Universe, or nothing ... " - H.G Wells </div>

silylene old · Jul 24, 2007

Jon, the scale is a natural log scale, so it is 'e' to the negative exponent. Sorry I wasn't clear. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

3488 · Jul 25, 2007

Hi all. MER A Spitirt Sol 1260. NavCam. It is brightening up, still hazy, but is a big improvement. As Jon Clarke correctly says, they will pull through. Excellent job by JPL to carry through the contingency plans. Looks like they have succeeded. Maybe the MERs will break 2,000 sols yet. I sincerely hope so. Tough rovers these MERs. I certainly think the lessons learned from the back to back failures of MCO & MPL have definately been learned. Well done NASA / JPL, this is what you do soooooooooo well. <img src="/images/icons/smile.gif" /> Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

Smersh · Jul 25, 2007

Yes guys. This seems like very good news so far. Let's keep our fingers crossed eh? <div class="Discussion_UserSignature"> <h1 style="margin:0pt;font-size:12px">----------------------------------------------------- </h1>Lady Nancy Astor: "Winston, if you were my husband, I'd poison your tea." Churchill: "Nancy, if you were my wife, I'd drink it."Website / forums </div>

MeteorWayne · Jul 25, 2007

Yes, it's too early to stop being concerned. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

3488 · Jul 27, 2007

It looks as if the improvement is continuing. MER B Opportunity has returned images for the first time in several sols. Below. Opposite Rim of Victoria Crater. Sol 1234. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

3488 · Jul 27, 2007

MER B Opportunity Mars Dial. Sol 1235. Shadow still pretty weak, but it is there, at least showing that some direct sunlight is getting through. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

MeteorWayne · Jul 27, 2007

That is indeed an improvement, and Oppy is still alive. Whew!! <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

Smersh · Jul 27, 2007

Here's a situ report from NASA dated yesterday ... MARS EXPLORATION ROVER STATUS REPORT: SPIRIT SEES DUSTIER SKY As of Thursday, July 26, NASA rovers Spirit and Opportunity are both enduring levels of reduced power supply. The rovers can survive at these levels, but NASA continues to sharply restrict their activities. Spirit is under the dustiest sky ever seen at that location. Sunlight at Spirit's location is more obscured than current conditions for Opportunity, though not as severe as what Opportunity faced a week ago. Full story <div class="Discussion_UserSignature"> <h1 style="margin:0pt;font-size:12px">----------------------------------------------------- </h1>Lady Nancy Astor: "Winston, if you were my husband, I'd poison your tea." Churchill: "Nancy, if you were my wife, I'd drink it."Website / forums </div>

3488 · Jul 30, 2007

MER A Spirit. Sol 1267. I see. The sky is extremely dusty. The hills of Thera Crater in the distance are sooooo hazy. Lets hope that this does not deterioate further. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

MeteorWayne · Aug 1, 2007

Bad news on Oppy from spaceflightnow "Concern increasing for Mars rover Opportunity MISSION STATUS REPORT Posted: July 31, 2007 Rover engineers are growing increasingly concerned about the temperature of vital electronics on NASA's Mars Exploration Rover Opportunity while the rover stays nearly inactive due to a series of dust storms that has lasted for more than a month. Dust in the atmosphere and dust settling onto Opportunity's solar panels challenges the ability of the solar panels to convert sunlight into enough electricity to supply the rover's needs. The most recent communication from Opportunity, received Monday, July 30, indicates that sunlight over the rover's Meridiani Planum location remains only slightly less obscured than during the dustiest days Opportunity survived in mid-July. With dust now accumulating on the solar panels, the rover is producing barely as much energy as it is using in a very-low-power regimen it has been following since July 18. Keeping Opportunity's activity to a minimum has reduced the amount of energy going into the rover's electronics core, reducing the amount of heat that comes from the electronics components themselves during normal operation. "The overnight low temperature of Opportunity's electronics module has been dropping since we implemented the very-low-power operation, even though the outside environment is actually warmer during this dust storm," said John Callas, rover project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. That temperature has dropped to minus 35 degrees Fahrenheit (minus 37 Celsius), within about 3 Fahrenheit degrees (about 2 Celsius degrees) of triggering survival heaters to turn on. Those heaters could push the rover's total use of electricity higher than what the solar panels produce, soon depleting the batteries. "This is e <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

arkady · Aug 1, 2007

argh! <crosses more fingers /> <gets straw for coffee /> <div class="Discussion_UserSignature"> "The choice is the Universe, or nothing ... " - H.G Wells </div>

3488 · Aug 1, 2007

Oh crap. It looked as if the situation was improving. Apparently not. Thanks MeteorWayne, for tipping us off. It is very bad news indeed. I was concerned at not only suspended dust, but also dust that had been whipped up, settling on the panels. It looks as if my concerns were perfectly justified, unfortunately. I hope very much, that it is still to early for anyone to write an Obituary to MER B Opportunity, but Oppy is in literally critical condition. How it had come to this, eh? Only a short while back, we were discussing the descent into Victoria Crater & / or going onto Ithaca Crater. Now it is looking as if it is all but over. Wonder how her twin is doing in Gusev???? Judging by the image i posted the other day, it was not looking too good there either. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

arkady · Aug 1, 2007

but, but ... I was so looking forward to the descent into Victoria. Think I'll just put on the optimistic hat and decide she will make it through. Btw, are the rovers, or spacecraft in general actually, usually referred to as male, female or just it/they? Never really noticed. Would make sense to me with female names just as is tradition with other kinds of vessels. <div class="Discussion_UserSignature"> "The choice is the Universe, or nothing ... " - H.G Wells </div>

3488 · Aug 1, 2007

Hi arkady, AFAIK, spacecraft are also 'she or her, etc'. I only hope that this is not the end of the mission, but as MeteorWayne pointed out, it is absolutely dire at Meridiani Planum right now. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

MeteorWayne · Aug 1, 2007

Well the girls <img src="/images/icons/smile.gif" /> are mighty spunky, so they just might survive the impossible, but it looks like this will be one tough test. From what I read in the rest of the article above, things are not yet as dire for Spirit. think warm thoughts <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

arkady · Aug 1, 2007

I'll be praying for clear skies and dustdevils it seems. <div class="Discussion_UserSignature"> "The choice is the Universe, or nothing ... " - H.G Wells </div>

vandivx · Aug 1, 2007

I was wondering a while back when the solar pannels miraculously cleaned up (that was before this current dust storm) why hadn't they been made on hinges with ability to be flipped over and maybe having solar sensitive pannels on both sides of the flappers, that would solve the issue of the dust settling on them vanDivX <div class="Discussion_UserSignature"> </div>

MeteorWayne · Aug 1, 2007

I'm not sure if that would help. AFAIK, the dust is very sticky, so flipping it over might not cause the dust to fall off. And then you are adding complexity and weight, both of which decrease the chances of success. Still, and interesting idea. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

heyscottie · Aug 1, 2007

There had been thoughts about including "windshield wiper" like technology to remove the dust, as well, but for a variety of reasons (added complexity and weight, possibility of scratching panels, and most notably, 90 day mission criteria), this was not added. I'm actually still fairly optimistic. The worst IS over; it's just not getting better fast enough. As long as power gains can stay ahead of power sinks, as has been the case so far, I think they'll pull through. They may, unfortunately, have restricted science afterward, though, if their panels are too coated to allow them to achieve as much per day as previously...

Huge Dust Storm on Mars.

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