Dust storm alert: Zephyria, 2020 March 8

[Dr Richard John McKim]

I have just posted the following alert on the Mars Section 2020 opposition blog page. This is accessed from the front page of the Section website, and earlier entries contain early images of the opposition.

March 9

Yesterday evening I received a dust storm alert from Clyde Foster (South Africa), whose image of March 8 (CML = 162, and at Ls = 163) shows a change since the previous day in the region of southern Zephyria (nearly up to the border with Aeolis), which was then following the CM. His own words are as follows:

“Bright cloud is visible over Olympus Mons (lower left) and the Tharis Montes (left). However, what was very noticeable to me was the significant change from yesterday in the region to the upper right of centre. There appears to be at least 3 discrete clouds. They are visible in B and G, but also definitely show bright in R and can also be detected in IR. They show a yellowish tinge as against the white clouds over the Tharsis region, which makes me suspect there is at least some dust component in the clouds.”

The Director compared this event with others in the BAA catalogue of dust storms. As soon as I saw the images I thought that the region was a rarely active one. I recalled there had been past events there in 1937 and 1969, and when I looked them up I found they had occurred at very similar Ls values.

The catalogue entries are:

1937 Jun 25-Jul 8 Ls = 174   SE Zephyria/Atlantis

1969 June 3-10    Ls = 167   SE Zephyria/Atlantis (longitude 173 deg.)

The 1969 event is illustrated in the catalogue.

Further observations of these regions are urgently required.

Richard McKim, Director

[Jeremy Shears]

Dear Richard,

excellent blog and thanks for the info about the dust storm.

Might we tempt you to speculate on how the dust storm might progress, if indeed it’s confirmed? I hope you have arranged for there not to be a major dust storm around opposition, unlike last time?

Jeremy

PS: well done to Clyde on his stunning images!!

[Dr Richard John McKim]

There has been further activity upon Mars. There was some local activity in Hellas, which now seems to be finished, a very brief episode of local dust activity in the Argyre basin, and a few days ago (possibly ongoing) there was some dust along Valles Marineris. Of course, the planet is still far from opposition and the disk tiny, but we need more well equipped observers to check all longitudes to provide a good level of coverage. The 2018 opposition showed that we must expect the unexpected….The Section’s 2020 blog has just been updated today. Good observing!

[Author]

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