The Storm, Dust storm of 2007 Options

[OWW]

Well, according to Mark Lemmon's site tau is now 3.3 for Spirit. Same as Oppy. Maybe it will stabilize around this value then.

Everybody says Martian dust storms begin in the summer. But what time of year IS it anyway? The official MER-site and the MMB both have very nice martian clocks, but no calendar!
Is it 'June', 'July' or 'August' now? And is there a comparison somewhere on the net with the 1971 and 2001 storms? In which 'months' did those storms start and decay?

[alan]

The southern summer solstice was last week.

[Greg Hullender]

For a Mars calendar/clock, I like Mars24:

http://www.giss.nasa.gov/tools/mars24/

--Greg

[elakdawalla]

And here's a table showing some past and future Mars seasonal dates. I have always intended to add some past ones going back to Mariner days, but never got around to sitting down with Mars24 and plugging dates in to find all the solstices and equinoxes.

http://planetary.org/explore/topics/mars/calendar.html

The Mars dust storm season begins just after perihelion at around Ls = 260°, wich is 10° (that is, 1/36 of a year or 1/3 "month", whatever that means for Mars) before the summer solstice.

--Emily

[MarsIsImportant]

Look at those drastic differences in the tracks after the new drive!

http://qt.exploratorium.edu/mars/opportuni...RZP2571L2M1.JPG

That's amazing. Does anyone know which days those tracks are from? I know the clear ones were just made.

[fredk]

That 255 whr figure for Sol 1225 is bugging me (Sorry Astr0 - feel free to object right back )

I calculate that at a Tau of 4.1 on Sol 1225 for Opportunity she should have generated around 310Whr.

Some updated numbers in the latest Oppy update:

The tau measurement as of sol 1225 is 4.12, resulting in a mere 280 watt-hours of array energy.

Also, some more details to add to the confusion about how much power Oppy needs to survive:

A tau measurement of 5.0 would result in approximately 150 watt-hours. If tau begins to approach 5.0, the team will have to begin deleting communications windows in order to conserve energy and keep from draining the batteries.

[mhoward]

Some updated numbers in [url=http://marsrovers.jpl.nasa.gov/mission/status_opportunityAll.html#sol1220]the latest Oppy update

Before anyone worries unduly, we should remind everyone that the news updates usually lag behind. Sol 1225 was the peak tau (as far as we've been told). It's now early on sol 1234 (heh, neat), and the tau is lower than that, unless it's spiked back up in the last two sols.

[OWW]

Actually....from mark lemmon's site:

Sol 1233B: Opacity B1233 was 3.8 but it got above 4 during the sol.

Continues to rise for both Oppy and Spirit. Unfortunately.

[mhoward]

D'oh. Okay, I guess it has spiked back up. How unfortunate.

[fredk]

Yeah, mhoward, I could have said "some updated old numbers".

Speaking of Lemmon's site, he also writes:

New sol 1233B: Special guest appearance by the first of several fast dust devil movies at Meridiani to characterize lifting near and beyond the crater rim.

What the heck does he mean by "lifting"? Lifting of dust as the storm subsides? It's not exactly subsiding! He says "fast dd movies" - does that mean they're looking for short time scale phenomena? Gusts of wind perhaps?? Any other ideas?

[CosmicRocker]

Yeah, I saw those frames come down today and wondered, "are they doing DD movies at Meridiani?" I suspect all of the frames are not down, but some looked to be fast, and others were many seconds apart. We at least seem to have parts of two movies so far.

I thought I noticed some subtle, local brightness variations in the sky among the available raw navcams. Maybe some of our "above the horizon" image magicians can find evidence of dust being lifted from the ground. That's what I think was meant by lifting.

The storm is certainly not subsiding yet. Meridiani and Gusev are experiencing new peaks. Searching for some good news, it sounds as if the rovers have plans for tau values around 5,

[djellison]

New record for Opportunity on B1234 of 4.2. Much kudos to Mark for keeping the figures updated despite being involved in a Phoenix ORT.

Doug

Attached thumbnail(s)

 

[nprev]

Oh my...not good. I searched in vain for the latest amateur Mars obs of this storm...anybody have any updates? This data suggests regional enrichment.

[djellison]

Damian Peach has put a few up at the BAA website ( www.britastro.org )

Doug

[OWW]

I also found this site:

http://elvis.rowan.edu/marswatch/news.php

Click on images on the left.