Spaceweather (www.spaceweather.com) is reporting a dust storm on Mars visible in amateur telescopes. Hope we don't get too much dust-fall on the solar panels....

Click to view attachment

Worth keeping an eye on but hopefully this will be short lived and not turn into a major storm. Chryse is a common location for "localised" storms so lets hope that the Rovers' luck holds out and this isn't the start of a big one.

On the other hand, it may provide a good science opportunity to study a Martian dust storm at the source.

Hope this one will NOT reach any MER rover !
Here is how it really looked like at Viking 1 landing site at Chryse on sol 324 of its mission during a storm (with image taken on sol 282 as a comparison)...
Enjoy ! (if I may say...)

Wow. Gets dark doesn't it. Are those piles of dust laying on the deck of the Viking Lander?

Scott

Ooh - nasty. Here's a chart of the Solar Panel output of a hypothetical MER-V1 roving around the Viking-1 site in 1976\77. If such a beast occurs Oppy and MER will see solar panel output reduce by about 75%.

Click to view attachment

The piles of dust were made trough soil sampling activities when soil was put inside the collector funnels of the soil analysis and biology instruments. Wind effects were quicky observed as piles of dust moved swiftly across the deck of the Lander which had a grid painted on it to measure such movements... However, at the end of the mission, after having endured 5 big dust storms, the VL1 lander deck and covers were losing their gray blue color and parts of them were already looking red-brown...
And, thanks to nuclear power energy, VL1 was still working !

Handy site to keep an eye on this storm feature as it develops (or fades).
Marswatch - Images and their Dust Monitoring page

Neat. I wondered if the Viking landers were ever in a dust storm. Fortunately they had RTGs for power.

Update on dust storm here with short interview with a MER team member on weathering a storm.

From the latest images there, I estimate the storm is currently roughly 2000km from the closest rover, Oppy.

Looks like the storm is getting bigger and it apparently has a green color when viewed from Earth. www.spaceweather.com

Latest storm picture from Ed Lomeli of Sacramento, CA:

Reminds me of a National Geographic from 1955 which declared a giant greenish patch appearing on Mars to be a huge field of some kind of plant life.

Had Mariners 4, 6, and 7 found more than just a lot of craters back in the late 1960s (leading to the assumption of Mars as a "dead" planet) and instead imaged the volcanoes, canyons, and valleys found by Mariner 9 just a few years later, it is likely we would have gone ahead with manned Mars missions in the 1980s.

I'll have to meet Ed. It looks like he's got a really nice telescope.

How frequently do global dust storms occur on Mars? I know there was one in 2001 and one in 1971 but that's all I'm aware of. Surely there must have been many more recorded in the last century.

It also looks like he's mastered the art of TouCam image-stacking - it's a joy to see amateurs taking such images!

Bob Shaw

There's a pattern to them, based on the rather more elliptical orbit which Mars has and which leads to the southern hemisphere having a greater range of temperatures than the north - colder winters, warmer (but still frigid) summers. Just count on dust storms at oppositions!

Bob Shaw

Somewhere I heard a quote that there had been 10 recorded since 1877.

Looking into it a bit further there appear to have planet wide storms in

1877 (Schiaparelli), 1909, 1924, 1941, 1956, 1971 (Mariner 9), 1973, 1977 (x2? Viking), 1994 and 2001.

James

There is fresh activity being seen VERY close to Opportunity, as visible in some of the imaging done earlier today.

5:30 UT : http://marswatch.amaonline.com/10-28-050030.jpg
6:00 UT through 7:59 UT : http://www.arksky.org/asoimg/MarAF4AD5A.jpg

I took Dr. P. Clay Sherrod's 07:38 image and fit it to a JPL Solar System Sim image of the same time, which I marked with Opportunity's landing site. I transfered that mark over onto a overlapping version of the webcam image and with permission from Dr. Sherrod I present it here to you.

It isn't a perfect lineup or position marking, though as you can see, a little difference goes a long way. This one is close!

I wonder what imagery Damien Peach has managed to get.

Doug

Whoah !!! thats close. Would Opportunity be able to see this in the sky?

I think yes. This looks in the order of tens of miles away. Oppy better start close her eyes.....or at least...find a way to point her panels to the sun as much as possible. This storm looks huge !! Any insights on the direction of atmospheric movement these time of year on Mars ? I hope it's going westward...

BTW, by convention, and I presume that they still do this, on astronomical images of planets, South is up.

I fear that this may be not-good for Oppy. Remember that we observed wind immediately blowing evaporite dust from the tracks the other day, so there is an increase in the wind velocity from the northwest.

--Bill

I think this dust storm is already on top of Oppy. It looks like to me that there is one "finger" of dust extending over Oppy's position. See the comparison of these images from the original observer:

http://www.arksky.org/asoimg/MarAF4B178.jpg

This could be a very serious situation.

The green colors in these images - are those real or artifacts? What is causing them if they are real?

On the ASO website http://www.arksky.org/asoimglib.htm (by "Object to Browse:" enter Mars, and "date:" 10.28.2005) there are some weird notes about this "dust storm". Do they wonder whether it be caused by an impact?

The green color was mentioned at http://spaceweather.com/ on Oct 21.
It may be a combintion of the yellow dust and high blue clouds

"The storm has seven appendages that stretch in all directions.
The overall cloud is about 700 to 800 miles across.
It is spreading at a speed of about 35 mph and may become larger by the weekend."

http://www.space.com/scienceastronomy/051028_mars_storm.html

Rakhir

You're absolutely correct. I rotated Sherrod's original image to north-up so as to conform to the JPL SSS image, and to make it a bit more familar for those who only know the Opportunity site from north-up maps. Sorry if that caused any confusion.

Good article, although they don't mention Sherrod's other comments (quoted below, re Tman's post #26) from the ASO web site or how close it is to Oppy. Have these kinds of odd "extensions" been seen before in Martian dust storms?

"There is an incredibly brilliant outbreak, perhaps yellow dust, between Margaritifer Sinus and Sinus Meridiani this morning, this developing from a minor yellow cloud just 24 hours ago. This feature is so bright that it is difficult to accurately image it without greatly underexposing the rest of the Martian features surrounding it. Note the (at least) seven (7) "fingers" or extensions that seem to radiate or spread outward from a large central area of unprecedented intensity. This odd area was first noted early this morning by Frank Melilo and Joel Warren and as it has rotated into view I believe that it has actually rapidly intensified in brightness. Hopefully west coast (USA) observers will get this as well.... I would appreciate the opinions and input of others, but honestly with the symmetry of the radiations emanating from this bright spot, I am not sure that we cannot rule out a catastrophic outflow, similar to that of eruption or even impact in nature. This does appear, because of the concentration in brilliance and the rapidity of development, to be extraordinary in nature."

There is also an animation now on the ASO web site.

OMG this is outstanding spectacular !

from the estimated spreading rate at 35mph and the close location to Opportunity it must be visibily already in the current images (at least as substantial darkening of the sky)
Too bad that the exploratorium site is down right now

So what does this storm mean for the rover ?

hopefully the degradation of solar power will be not too bad to kill the rover
eventually..

on the other hand: if Oppy survives this, then chances are that the panel are
more clean than before due to the dust cleaning effects of the high wind speeds...

This is going to become a really exciting development

I'm not sure how "tall" a martian dust storm is. A 100 meter object would be just visible from about 20 km away. But, given that the object is dust, and the background is the already-dusty sky of Mars, it might have to be a lot closer to be visible. The easiest way to detect it would be to notice the setting sun passing into the storm.

Given the speed at which the storm is traveling, it could arrive before any image seeing it in the distance is taken -- unless an imaging campaign devoted to this is undertaken.

"Opportunity has seen some signs of the dust storm, which is apparently nearby.

Opportunity showed elevated dust levels, which were measured at an optical depth of about 1.4. The largest dust storm experienced by the rover occurred in June and rated an optical depth of about 2.

For comparison, a smoggy day in Los Angeles would rate an optical depth of about 1.0, and moderate days on Mars are about 0.5

"We started seeing more and more dusting on the solar panels," Mark Lemmon added. "And we have indirect evidence that these storms are windy. We've seen material blown out of the rover tracks over the last two weeks."

Meanwhile, Spirit has found some signs of additional atmospheric dust at Gusev Crater. She detected an optical depth of about 0.6"

http://space.com/scienceastronomy/051028_mars_storm.html

Rakhir

Do you have the URL handy? I'm not familiar with ASO's web site, and I've been unable to find any obvious link to this animation thus far..

Mike, you have to start with the link and guidance in my post#26. http://www.unmannedspaceflight.com/index.p...indpost&p=24766

It's also the site where they show the pictures and the animation.

http://www.arksky.org/smf/index.php?topic=833.0

Just wondering if the "extraordinary" brightness of this dust\storm\wotsit event is related to opposition surge:



From Marswatch

On the FwdHazcam and RearHazcam images from Sol 625 I thought that both looked a bit "hazy" with bright shadows.

Fwd HazCam

Rear HazCam


--Bill

However, these pictures were taken three days ago. Now it is sol 628. The Tau would be around 1.4 (like almost sunset) and the worst that Oppy has experienced was around 2.0 on June of last year. After that, the wind will clean again the dust from plan solars and hope it would be even better when it is close to Mogollon rim.

Rodolfo

I wish we could get to see some dust storm images from Odyssey, Mars Global Surveyour and Mars Express.

Dr. Sherrod has captured the storm activity again tonight, to which I've added Opportunity's position.

The odds on a major planet encircling storm seem to be around 20% per Martian year or one every decade or so for us Earthlings. The last global storm was in 2001 - heres a nice write up and animation from TES .

Previous major storms were seen in 1909, 1924, 1956, 1971, 1973, 1975, 1977 (twice) and 1982 although apparently only the 1971 event is considered global in that it obscured the whole planet apart from the tops of the Tharsis peaks. Nice write up here by Jeff Beish

There was a fairly significant non planetwide storm in 2003 that was concentrated in Hellas and lasted for most of December 2003.

Could the dust storm be a serious matter for our intrepid explorer? I am assuming that if the dust storm does hit and decrease the solar panel output to below the minimum, Oppy can go into a deep sleep mode and wait the storm out, waking up once the storm clears. And if the solar panels get dusted over, we'll wait for a cleaning event. Or am I too accustomed to Oppy being The Energizer Mars Rover?

--Bill

Bill:

We're talking End Of Mission!

Bob Shaw

That's what I was afraid of...

--Bill

We're only talking end of mission if things get really bad and stay that way. Oppy's been generating somewhere in the 600Watt/hours per day range lately. An extended period where Tau is around 2 would reduce that by 20-30% which would make things more difficult but wouldn't kill her. A really major event (Tau~ 5) would bring that down to around 240 Watt/hours which is below the level that I think she needs to survive for an extended period. Even at that level though I think there would be enough juice to wake up and blip out a "Hello I'm still more or less alive" direct to earth message.

To give you an idea what a major planetwide storm would do - the second 1997 storm had Tau > 4 for approximately 36 Sols (based on a model from Viking data) and Tau >2 for about 80 sols. It's important to remember that the general consensus is that we're too late in the season for a storm like that.

The

ok, I'm confident that the Rover could survive during the duration of most dust storms but the question is: how does the storm affect the accumulation on the solar panels *after* the storm ?

I'm afraid that the wind itself ceases long before the majority of the dust (very light particles !) eventually falls out of the atmosphere:

this could be bad because all the dust that had been kicked high up into the atmosphere would now slowly trickle out of the air like snow-flakes on a windless winter day, accumulating on the solar panels without the wind necessary to blow it away ...

Question for the experts (hevlick ?): how did the dust accumulation develop after past dust storms that Oppy observed ?

on the other hand if some of the increased wind activity associated with the dust storm continues shortly after much of the dust has fallen back to the ground, then
it could even improve the solar panel situation by "wind cleaning events"

Firtly I'm not an expert - just an amateur trying to understand something that intrigues me and would really love for a real expert to chime in if there are any reading.

What should happen (obviously) is that dust that is elevated by storms and dust devils will then settle out of the atmosphere over some period of time. Assuming that the Tau levels give some indication of that rate (which is not wholly correct I know) then looking at Spirit's Tau levels at the start of the mission it appears that this settling out process at the end of the last Martian Summer took about 140-150 sols. There was a pretty big storm centered on Hellas for most of December 2003 which cleared up just as Spirit landed. Tau at the Spirit Site started off at ~0.9, fell to ~0.55 by Sol 90 and then reached a stable level of around 0.3 on Sol 145 where it stayed until ~ Sol 350. One of the published MER papers confirms that the rate of power lost due to dust deposition during the primary mission followed the expected model which I take to mean that it dropped off at approximately 0.18% per Sol. So a big storm like the 2003 one at the end of summer would mean that the long term impact of dust loss moving through autumn and into winter would be around 30% which isn't too bad. It would also be fair to say that if Tau is around 1 when the Rover's first martian anniversary happens in a few weeks then we should expect the same ~30% dust loss over the following 150 Sols. It's worth pointing out that Opportunity is currently generating power in "the high 600's" which is 15-20% below what it would generate if there was no dust loss. IF things stabilise and follow the pattern from the start of the mission then the power output at mid winter will be about 340 Watt hours unless they happen to find themselves stopped on an unfavourable inclide.

Ok, the dust storm has hit Meridiani



Good luck Oppy

Youcha. I think a lot of that is because of the low sun causing an awkward stretch of the JPG - but the rover has got a LOT of camera-dust recently.

This one is stretched back a bit because of the missing data and it feels very very strange..

http://marsrovers.nasa.gov/gallery/all/1/f...23P1211L0M1.JPG


Doug