LtE in CMO #276

From Thomas A DOBBINS

® . . . . . . . .Date: Tue, 29 Jul 2003 12:06:04 -0400

From: Tom Dobbins <r&>

To: <>

Subject: Mars news


On 7/29/03 11:01 AM, "Masatsugu MINAMI" <> wrote:


Please see my remarks inserted below...


> Dear Tom,


> Thank you for your nice instruction before for the flare

> observation on Mars.


> We are going to start tomorrow (30 July) and repeat five nights

> until 3 August under ISHADOH's superintendence in Naha. We are

> expecting De=Ds will occur on 1 August.


> Members and instruments are not adequate, and so we just choose

> no more than the possible hours. We suppose the reflector on

> Mars is put lateral in a shallow trench.


> Recently the phase angle decreased to 25 degrees and so since

> 25/2 ~15 degs, we shall start one hour before the point comes to

> the CM and basically quit observing when the candidate place

> reaches the CM. Is it OK? Should we prolong our watching time?


Perhaps by as much as two hours from the time of CM transit... I hope that the news of flares on July 22 9:53 UT near Solis Lacus has reached you. From memory, the CM at the time was 85.5 degrees, the site was at latitude -19, longitude (more approximate) 110. This event was seen by an amateur in Fort Myers, Florida (on the coast of the Gulf of Mexico) named Paul Atkinson using a C-14 at 400X+ in excellent seeing as two brief flashes, each of about one second duration. Don Parker and I have spoken with him by telephone and find the report very credible. His attention was directed at other features at the time, and he was only vaguely aware of the flare vigil. Like the 2001 flare at Edom, this event suggests very little inclination of the reflector on a north-south axis, but an appreciable inclination on an east-west axis. Puzzling...


Paul will be joining the gathering at my home on August 4 that will include Don Parker, Walter Haas, John Westfall, Bill Sheehan, Richard Schmude, Eric Ng, Tan Wei-Leong, and Ed Grafton. ("The greatest concentration of talent since Thomas Jefferson dined alone at Monticello.") Later I will send a detailed account and photos of our meeting.


> It is however difficult to choose the object point. Maybe

> FUKUI's spot.


Yes, probably the best candidate.


> Do you see the yellowish white haze is now covering the whole

> surface of the red planet, and it has become the Yellow Planet?

> The details are still seen (just because the angular diameter is

> de-ja extraordinary) but the markings are quite obscured and the

> gradation of the markings has been decreased. ToUcammunists just

> want the details, and so the most of recent ccd images without

> the description of thin overall yellowish-white haze look

> nonsense for study. I hope the obscuration does not obstruct the

> flare observations.


I enjoyed a splendid view of Mars on the morning of 26 July under conditions of very stable air but poor transparency (fog). You are correct, the contrast between the maria and deserts is quite muted compared to early June 2001.


By the way, I suspect a subtle change in the albedo feature known as Aryn on old maps - this bright indentation in the "underside" (i.e. the northern side) of Meridiani Sinus seems darker and reduced in extent compared to 2001, making the characteristic two-pronged "fork" appearance of "Dawes Forked Bay" in Proctor's old nomenclature less evident.


I am pleased to report that the Adirondack Atmospheric Dispersion Corrector performs very well, and this device (consisting of a pair of counter-rotating 2-degree wedge prisms) has made it possible for me torecord beautiful color video of Mars at an elevation of less than 30 degrees without red and blue fringes. (In the coming weeks I will extract some still images from these tapes.) Parker has also been using one successfully in the Keys during the past week.


> In Okinawa, the streaming clouds often appear, and so we may

> miss the chance during the time when we are temporarily clouded.

> At the Florida Keys, were you very confident about the clear

> skies every night at that season?


No, summer weather in the Keys can be poor due to the onset of the Atlantic hurricane season every June. During our 2001 visit the skies over the Keys remained clear almost by a miracle - a powerful storm churning over the Gulf of Mexico made Texas, Louisiana, and much of the Florida peninsula rainy and overcast. We remained just out of the storm's reach, but it was quite windy during our entire stay. (Windy weather here in Ohio and other continental locations almost invariably is accompanied by poor seeing, but in the Keys the seeing remained very good even in gusting winds.)


 Tom DOBBINS  (Coshocton, OH, USA)

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