Solar&Planetary LtE Now for CMO/ISMO #105 (CMO #479)

Solar & Planetary LtE Now for CMO/ISMO #105 (CMO #479)

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¤·····Subject: Mars images on 30 November

Received: 30 November 2018 at 23:08 JST

Mars images on 30 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181130/Ak30Nov18.png

Tomio AKUTSU (Ibaraki, JAPAN)

¤·····Subject: Mars　M181130 ishibashi

Received: 30 November 2018 at 22:36 JST

Mars images on 30 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181130/Is30Nov18.png

Tsutomu ISHIBASHI (Kanagawa, JAPAN)

¤·····Subject: Mars 2018/11/30-Kumamori

Received: 30 November 2018 at 22:37 JST

Mars images on 30 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181130/Km30Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars 2018/11/29-Kumamori

Received: 29 November 2018 at 23:32 JST

Mars images on 29 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181129/Km29Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Percival Lowell article for CMO

Received: 29 November 2018 at 05:34 JST

Dear Mastatsugu and Masami,
   I have been working on a new Mars book, and unfortunately have found that the chapter on Percival Lowell is far too long, and have—though somewhat regrettably—had to cut out most of what I wrote about the Japan phase of Lowell’s adventurous life. I am sending it as an attachment, in case—now that Mars is again scuttling away from us—you may wish to publish it as one of your off-year features, if you find it of interest.
   Regards,

Bill Sheehan (flagstaff, AZ)

¤·····Subject: Mars 28 November 2018 1646UT IR.

Received: 29 November 2018 at 03:40 JST

Hi all,

Poor conditions this evening, so I was limited to IR. The view looks down on the Insight lander and Curiosity rover sites.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181128/CFs28Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars　2018/11/24

Received: 28 November 2018 at 20:56 JST

Mars images on 24 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181124/Oz24Nov18.png

Kimikazu OZAKI (Aichi, JAPAN)

¤·····Subject: Uranus (November 26th.)

Received: 28 November 2018 at 06:59 JST

Hi all,

Here is an image of Uranus from November 26th. Good seeing. This is a false colour IR685nm image. The bright polar region is prominent and also a faint equatorial band. No storms were detected.

http://www.damianpeach.com/uran2018-11-26-0149_2-IR685dp.jpg

Best Wishes

Damian PEACH (Selsey, WS, the UK)

http://www.damianpeach.com/

¤·····Subject: Mars 27 November 2018 1708UT RGB and IR. NASA Insight tribute.

Received: 28 November 2018 at 05:40 JST

Hi all,

I thought that I had used up my supply of goosebumps as I followed the touchdown of the NASA Insight Lander yesterday. But as Mars came on screen this evening, less than 24h after the touchdown, I found myself getting quite emotional as I gazed down, in real time, on the region where Insight has made its new home, and where it will hopefully, in the coming months, perform amazing science.

Over and above my standard image set, I have included a tribute image to the Insight mission team, who did such an amazing job of getting the spacecraft to the surface safely. The approximate landing site is marked with a red “X”

We live in amazing times.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181127/CFs27Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars 2018/11/27-Kumamori

Received: 28 November 2018 at 00:01 JST

Mars images on 27 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181127/Km27Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars images on 27 November

Received: 27 November 2018 at 23:24 JST

Mars images on 27 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181127/Ak27Nov18.png

Tomio AKUTSU (Ibaraki, JAPAN)

¤·····Subject: Mars　M181127 ishibashi

Received: 27 November 2018 at 23:09 JST

Mars images on 27 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181127/Is27Nov18.png

Tsutomu ISHIBASHI (Kanagawa, JAPAN)

¤·····Subject: Mars images on 14, 15 & 25 November

Received: 27 November 2018 at 00:18 JST

Mars images on 14, 15 & 25 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181114/Ak14Nov18.png

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181115/Ak15Nov18.png

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181125/Ak25Nov18.png

Tomio AKUTSU (Ibaraki, JAPAN)

¤·····Subject: Mars

Received: 26 November 2018 at 09:29 JST

Hi to All!, Here are some recovered sets and my latest session of Mars.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181120/EMr20Nov18.png

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181017/EMr17Oct18.png

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181012/EMr12Oct18.png

Efrain MORALES RIVERA (Aguadilla, Puerto Rico)

¤·····Subject: Uranus/Neptune Spectra 2018 November 18th

Received: 26 November 2018 at 01:42 JST

Hi all,

Here are my first experiences with low-res spectra on Uranus and Neptune. These are calibrated and corrected data by dividing the raw spectrum of each planet by the raw spectrum of a nearby solar-like star (details are on the sets). Original data is also corrected from offset, dark, and flat.

Results look correct in that the Neptune spectrum is brighter in blue and Uranus slightly more in green.

I have some more projects about this:

1) Try to obtain a full spectrum with IR part. This cannot be done by one shoot as there is an overlapping of the 1st and 2nd order after 750 nm.

2) Try to calculate BRVI magnitudes. This is quite more ambitious but it would be already more interesting.

Best wishes,

Christophe PELLIER (Nantes, FRANCE)

Planetary astronomy and imaging

¤·····Subject: Mars images - November 23

Received: 25 November 2018 at 15:27 JST

Gentlemen,

Seeing was better than average (3/5 - 4/5). Transparency was fair. Local transit was at 23:10UT.

Regards,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181123/PGc23Nov18.png

Peter GORCZYNSKI (Oxford, CT)

¤·····Subject: Mars: November 24, 2018

Received: 25 November 2018 at 11:00 JST

Hi ,

I have attached my latest images of Mars November 24, 2018 between 1:00 UT and 1:35 UT.

Thanks,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181124/FMl24Nov18.png

Frank J MELILLO (Holtsville, NY)

¤·····Subject: Mars 2018/11/24-Kumamori

Received: 25 November 2018 at 00:18 JST

Mars images on 24 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181124/Km24Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars　2018/11/20

Received: 24 November 2018 at 21:18 JST

Mars images on 20 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181120/Oz20Nov18.png

Kimikazu OZAKI (Aichi, JAPAN)

¤·····Subject: Mars: November 23, 2018

Received: 24 November 2018 at 14:34 JST

Hi,

I have attached my images of Mars November 23, 2018 between 22:48 UT and 23:13 UT

Thanks,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181123/FMl23Nov18.png

Frank J MELILLO (Holtsville, NY)

¤·····Subject: Mars 22 November 2018 1717UT IR.

Received: 23 November 2018 at 04:18 JST

Hi all,

Clear skies but very poor seeing conditions limited me to this IR from this evening.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181122/CFs22Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars　M181122 ishibashi

Received: 22 November 2018 at 21:24 JST

Mars images on 22 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181122/Is22Nov18.png

Tsutomu ISHIBASHI (Kanagawa, JAPAN)

¤·····Subject: Mars 21 November 2018 1725UT RGB and IR.

Received: 22 November 2018 at 18:59 JST

Hi all,

Mars image set from yesterday evening, with Hellas and Syrtis Major central.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181121/CFs21Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars 2018/11/20-Kumamori

Received: 21 November 2018 at 11:50 JST

Mars images on 20 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181120/Km20Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Jupiter images (May 8th.)

Received: 21 November 2018 at 07:36 JST

Hi all,

Excellent seeing for these images on May 8th.

Note Io is occulting its own shadow due to Jupiter being very close to opposition.

http://www.damianpeach.com/barbados18/2018-05-08-0353_1-RGBdp.jpg

http://www.damianpeach.com/barbados18/2018-05-08-0227_7-RGBdp.jpg

Best Wishes

Damian PEACH (Selsey, WS, the UK)

http://www.damianpeach.com/

¤·····Subject: Mars 20 November 2018 1659UT RGB and IR

Received: 21 November 2018 at 04:37 JST

Hi all,

A very short gap in the ongoing cloudy conditions allowed capture of this image set from this evening.

Hellas and Syrtis Major are prominent. The markings in Hellas are best seen in IR.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181120/CFs20Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Uranus 15th November 2018

Received: 19 November 2018 at 01:07 JST

Hi all,

Here are 5 consecutive images of Uranus taken in 2 hours. Seeing was good. However even in animation I don't see the storm (following Marc's ephemeris it could have been visible that night at 64° long. Thanks Marc). So either it is not resolved, or not there, or faded already !

Regards

Christophe PELLIER (Nantes, FRANCE)

Planetary astronomy and imaging

¤·····Subject: Mars 2018/11/17-Kumamori

Received: 18 November 2018 at 17:42 JST

Mars images on 17 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181117/Km17Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars images 24 October and 15 November

Received: 18 November 2018 at 00:10 JST

Hi all,
Some late images taken under good to very good seeing, as the planet is now reaching better elevations from here.

Regards

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181115/CPl15Nov18.png

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181024/CPl24Oct18.png

Christophe PELLIER (Nantes, FRANCE)

Planetary astronomy and imaging

¤·····Subject: Mars　M181117 ishibashi

Received: 17 November 2018 at 22:25 JST

Mars images on 17 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181117/Is17Nov18.png

Tsutomu ISHIBASHI (Kanagawa, JAPAN)

¤·····Subject: Alert: storm on Uranus - ephemeris

Received: 17 November 2018 at 22:13 JST

Dears,

A storm on the edge of Uranus' bright boreal polar zone is visible. That would be the first one well visible since 2014! Here is an animation taken with Mont Wilson's 1.5m reflector : http://alpo-j.asahikawa-med.ac.jp/kk18/u181022a3.gif

According to my analysis, several amateurs have observed a similar feature, and 4 of those observations are coherent with the wind speed at this latitude and Blake's observation. I could then calculate the following tentative ephemeris, to be confirmed:

Now it's up to you (one of the observations was made with a 20cm reflector), and above all please send me your images (delcroix point marc at free point fr), indicating at least on the image:
- mid-time acquisition (UT)
- filter
- your name
and have a processing leaving the satellite(s) visible (do not raise the black level too much) so I could calibrate and measure your observations.

Steady skies

Marc DELCROIX (Tournefeuille, FRANCE)

http://astrosurf.com/delcroix

¤·····Subject: Saheki tithonius lacks observation

Received: 17 November 2018 at 05:44 JST

Dear Murakami and Dr. Mnami,
   I have been working on a new Mars book (with Jim Bell of Arizona State University), in which I have mainly been concerned with the history and he is doing the spacecraft era. (Jim is the Principal investigator for the 2020 Mars rover camera system.) In the course of my researches and writing, I came again to Tsuneo Saheki’s August 8, 1951 flare observation, which really seems quite unique in the records of studies of the planet. Though the observation was quite widely discussed at the time, all of the explanations—specular reflections from mountain ice, volcanic eruptions, meteorological phenomena, or a nuclear bomb explosion—have seemingly been ruled out. The only remaining option seems to be a meteorite impact. Jim Bell and several other Mars scientists with whom I have discussed this the matter are in agreement. If so, then Saheki is the only person to have seen such an event in real time.
   I did a back of envelope calculation, and concluded that the flash—to be visible from Mars at the great distance it was at the time (with an apparent diameter of 5.3”) would likely to have been produced by a blast in the megatonnage range. Alfred McEwen at the University of Arizona indicated that this likely means formation of a crater at least 700 meters across, and Jim Skinner, a geologist at the USGS in Flagstaff, has gotten interested in the problem (see below) and has offered to devote resources to searching for such a feature. What would greatly help us if you could provide any information, sketches, etc. that would help us to make a more targeted location possible. Though I memorably visited the Saheki family (with Minami-san and others) in 2004, and saw his telescope and also looked at some of his observing sketches, I did not see any records showing the 1951 event.
   It would certainly be a great achievement if we could find a crater in the location where the legendary Japanese observer indicated the flash.
   All best wishes,
   Bill
    -----------------------------------------------------------

Thanks for the contact. The documented activity by Saheki is really quite interesting. It might be possible to locate an impact crater, though I admit it is much like looking for a needle in a haystack at that diameter. Based on what Alfred indicated, we would theoretically look for something around 1 km or below (down to 200 meters). The boundaries of Tithonius Lacus are fairly poorly defined ... occurring somewhere between +2 to -8 degree N latitude and 265 to 285 E longitude, based on Antoniadi's map as depicted in Blunck's nomenclature book. The sketches by Saheki are of too low resolution to make a targeted location possible. Is there any more information, sketches, etc. that you have that would help narrow down the field of investigation? There are many CTX images in that region to make a systematic search possible. I can ask our data gurus to pull a section of a CTX mosaic and get a student to take a look a systematic look. We would look for a <1 km crater with no superposing craters (of any diameter), with possible rays, identifiable ejecta, and sharp rim. This area is extremely dusty and it is possible that parts of the crater and ejecta might be thinly buried and obscured. If you have any information at all that can help narrow the area, that would be extremely helpful if not absolutely critical.

It occurs to me that Tithonius Lacus is part of the broader Valles Marineris canyon system wherein landslides have occurred for eons. A landslide could reasonably create a reflective plume of dust that would eventually settle within the time frame reported. It could also occur in conjunction with (and be initiated by) a local impact due to inherent slope instabilities on Mars. Unfortunately, there are no landslides that have been documented as geologically recent, and certainly none as young as 70 years young. However, we can also peruse the CTX excerpt for youthful landslides and see if the community has missed anything.

More to come.

Jim

-----------------------------------------------------------

Bill Sheehan (flagstaff, AZ)

¤·····Subject: Mars 16 November 2018 1659UT RGB and IR.

Received: 17 November 2018 at 05:10 JST

Hi all,

After a period of cloudy evenings, I had a short gap this evening for this image set before more clouds came over. Hellas was very bright with interior markings showing in IR and R. The SPC is very small.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181116/CFs16Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars 2018/11/15-Kumamori

Received: 15 November 2018 at 23:40 JST

Mars images on 15 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181115/Km15Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars　M181114 ishibashi

Received: 15 November 2018 at 14:58 JST

Mars images on 14 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181114/Is14Nov18.png

Tsutomu ISHIBASHI (Kanagawa, JAPAN)

¤·····Subject: Mars good seeing (November 9th.)

Received: 14 November 2018 at 05:42 JST

Hi all,

Good seeing again on the 9th. A nice view of Mare Sirenum.

http://www.damianpeach.com/mars2018/m2018_11_09dp.jpg

Best Wishes

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181109/DPc09Nov18.png

Damian PEACH (Selsey, WS, the UK)

http://www.damianpeach.com/

¤·····Subject: Fw: Re: Saheki asteroid impact on Mars?

Received: 13 November 2018 at 14:11 JST

----- Original Message -----
From: Jim Bell
To: William Sheehan, William Hartmann, vzv03210@nifty.com

Subject: Re: Saheki asteroid impact on Mars?
Date: Mon, 12 Nov 2018 20:04:12 +0000

Interesting. Of course, all such estimates (including Saheki’s original magnitude estimate) are fraught with uncertainties.

Running this by Ingrid Daubar could be interesting. She’s now at Ingrid.Daubar@jpl.nasa.gov. Tell her I sent you…

Thanks,

Jim

Jim Bell

--------------------------------------------------------------------------------

From: William Sheehan

Date: Friday, November 9, 2018 at 9:56 AM
To: Jim Bell, illiam Hartmann, "vzv03210@nifty.com"

Subject: Saheki asteroid impact on Mars?

Dear Jim, Bill, and Masatsugu,

I did a very rough back of envelope calculation to see what kind of asteroid impact would create a flare as bright as a sixth magnitude star with Mars was so far away (apparent diameter 5”3), as described by Saheki in his remarkable observation at Tithonius Lacus (approx. 85o long., -4o lat.) of Dec. 8, 1951. I did a lot of rounding but came up with a result in the 50-100 megaton range—probably an overestimate, but of the magnitude of the “Tsar Bomba” explosion in 1961. I would guess an explosion of this magnitude would result in an impact crater in the tens of kilometer range. This is, of course, far greater than any of the fresh craters formed in the past 20 years mentioned in the Journal of Geophysical Research Planets paper by Dauber et al. (The maximum size of craters they found were in the 20-30m range.)

It seems extremely improbable that such a large crater could have formed and not left telltale signs all over that region of the planet, and this leads me to think it more likely (given the position of the “flare” near the limb) that a very high altitude cloud was being illuminated at this point.

Would it be worth running this by some of the authors of the small fresh craters paper in the Journal of Geophysical Research, such as Daubar, Atwood-Stone, Byrne, or McEwen?

I have included Saheki’s drawings below. His skill must be regarded as beyond question.

Best, Bill

--------------------------------------------------------------------------------

¤·····Subject: Mars: November 12, 2018

Received: 13 November 2018 at 12:39 JST

Hi ,

I am sending you my latest image of Mars November 12, 2018 at 1:53 UT.

Thanks,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181112/FMl12Nov18.png

Frank J MELILLO (Holtsville, NY)

¤·····Subject: Mars 2018/11/11-Kumamori

Received: 12 November 2018 at 15:58 JST

Mars images on 11 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181111/Km11Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars good seeing (November 7th.)

Received: 12 November 2018 at 07:53 JST

Hi all,

Good seeing on Nov 7th. A nice view of the Elysium hemisphere despite the dwindling apparent diameter. Small SPC at bottom.

http://www.damianpeach.com/mars2018/m2018_11_07dp.jpg

Best Wishes

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181107/DPc07Nov18.png

Damian PEACH (Selsey, WS, the UK)

http://www.damianpeach.com/

¤·····Subject: Jupiter photometry of belts and zones, 2018

Received: 12 November 2018 at 00:58 JST

Hi all,

Over the last months I have tried to develop some methods for a more objective following of the evolution of jovian clouds colors.

I'm using a Star Analyzer 100. If one rotates the camera in a right way, the low-res spectrum obtained is displaying values for all resolved belts and zones. With a bit of care, it looked possible to extract smaller spectra for the main belts and zones, so I cropped EZ, STrZ, SEB, and NEB (I'm skipping details of the process, it is more complicated than that).

The spectra are corrected for instrument response and atmospheric exctinction using adjacent A3 star Beta Librae. The project was not to find the proper albedo of the planet (which requires division by a G2V solar star) but to measure color photometry. While in theory the instrumental response will not vary with the type of the reference star, it is just more easy to calculate with white or blue stars.

You will find attached various presentations of some results:

1) A comparison of the absolute photometry of the four regions (... relatively to EZ). The comparison is coherent with images taken at that time, with STrZ being the brightest region of the planet in UV and blue, while after 490 nm the EZ is recovering its normal first place. The yellowness of the EZ can be deduced from its steeper drop in UV/B albedo. Without surprise, the two equatorial belts are noticeably less bright than the zones.

2) Individual spectrum for each of the four regions processed under Rspec, and one for the whole planet.

3) An attempt at making north-south photometric cuts for relevant wavelengths. I tried to match the UBRVI johnson bands (only I is different, because the photometric I band's center wavelength falls on the CH4 absorption band!). I've been trying to calibrate those but did not succeed and I would welcome help or advices.

My project is to repeat that work for each jovian apparitions and to try enhancing objective color changes on main belts and zones. Maybe more ideas could follow ?

Christophe

PS I can give any detail of how I process the data if needed.

Christophe PELLIER (Nantes, FRANCE)
Planetary astronomy and imaging

¤·····Subject: Mars images on 7 & 11 November

Received: 11 November 2018 at 23:25 JST

Mars images on 7 & 11 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181107/Ak07Nov18.png

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181111/Ak11Nov18.png

Tomio AKUTSU (Ibaraki, JAPAN)

¤·····Subject:Mars 10 November 2018 1743UT RGB and IR.

Received: 11 November 2018 at 17:46 JST

Hi all,

I managed to capture some Mars data in amongst all the rugby yesterday afternoon and evening. Turns out conditions were quite good. It is becoming more challenging with the planet now reducing towards 10 arc-seconds in diameter.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181110/CFs10Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars: November 9, 2018

Received: 10 November 2018 at 12:14 JST

Hi,

I have attached my latest image of Mars November 9, 2018 at 1:36 UT.

Thanks,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181109/FMl09Nov18.png

Frank J MELILLO (Holtsville, NY)

¤·····Subject: Fwd: Saheki's flash at Tithonius Lacus

Received: 7 November 2018 at 07:03 JST

Dear Masatsugu and other CMO editors,

I have been working on a new book with Jim Bell, for U of Arizona Press. In the course of my writing, I came to Saheki’s observation of Dec. 1951, in which he saw a bright flash?estimated to rival a sixth magnitude star, even though Mars was only 5.3” of arc across. Jim agrees that the only possible explanation for this must be a meteorite impact.

We are trying to estimate the size of crater that would likely be formed by a blast visible from Earth with Mars so remote, and I am also asking for the views of Bill Hartmann, who is the expert on such things.

It would be gratifying to be able to identify the crater that Saheki saw forming! He must always be remembered as one of the greatest of all Mars observers, and I feel greatly privileged to have met his wife and family at Osaka in 2004.

Regards,

Bill Sheehan

Begin forwarded message:

From: Jim Bell

Subject: Re: Saheki's flash at Tithonius Lacus

Date: November 4, 2018 at 2:58:14 PM MST

To: William Sheehan

Hi Bill,

I’m working on a chapter this weekend, too. Gotta keep pushing myself to crank this out!

I think that most Mars scientists today would favor the idea that Saheki possibly observed a small (or not so small) impact cratering event on Mars ? perhaps thus becoming the first and so far only person to observe one on Mars in real time*. As you are probably aware, and which I will discuss in my chapter on MRO and HiRISE, we’ve now detected HUNDREDS of small new impact craters that have formed on Mars over the past 40+ years of near-constant orbital monitoring. Most of these are quite small, of course, only a few tens of meters across, but those events occur in a continuum of sizes from very common small ones to much rarer larger ones. Perhaps Saheki was lucky enough to see a rarer, larger one that created a more impressive impact explosion and plume? It would be interesting to look through the population of new craters discovered in the last few decades and see if there’s anything that appeared in that area (any idea how precise his lat/lon estimate was?). I don’t know of any single particular outlier “big one” that’s been discovered, but they are somewhat hard to find unless they occur in bright (dusty) areas, because it’s the dust disturbance and excavation of the darker material below that provides most of the contrast to notice them in before/after pictures over time.

See, for example, this one, which is perhaps still the largest yet found:

https://www.jpl.nasa.gov/news/news.php?release=2014-162

More typical is this recent one:

https://mars.nasa.gov/resources/21891/a-new-impact-crater/

And this older one:

http://www.msss.com/msss_images/2009/09/24/

See also the attached PDF, representing a bunch of work on this from the HiRISE team…

Thanks for the fun diversion… Reminds me that we will need to be looking for ways to more strongly link your part of the book to mine, maybe with some added text/pointers/footnotes later ? this is one example! (don’t forget!)

-Jim

*While no one has definitively (digitally) recorded impact flashes on Mars, many have been found on the Moon. See, for example, https://www.nasa.gov/centers/marshall/news/lunar/index.html

These can help to calibrate the brightness of the flash with the energy (size) of the event. Did Saheki estimate a magnitude for his flash?
>>
From: William Sheehan
Date: Sunday, November 4, 2018 at 1:38 PM
To: Jim Bell
Subject: Saheki's flash at Tithonius Lacus

Hi, Jim,
I’m working on the Mars book this afternoon. I’ve introduced a brief discussion of the flashes seen from time to time on Mars, and have come to the curious observation made in 1951 by Tsuneo Saheki (whose family I actually visited and had dinner with in Osaka in 2004). You can read the whole description; but the gist is?he was observing Mars, very small at the time, when he saw a bright flash (he said it rivaled the North Polar Cap and was probably about as bright as a sixth magnitude star) at Tithonius Lacus, which is as you know
in the martian Valles Marineris complex. It twinkled brightly for about five minutes, then faded and became “only a common white cloud near the limb,” and then disappeared.

It wasn’t near the subsolar point. At the time it was thought it might be a meteorite impact, or even an “atom bomb” going off on Mars. I suspect the most likely explanation was that it was a reflection of sunlight off some of the fog or mist that clings to the sides of the canyons, but I wanted to see what you thought.

There have been subsolar specular reflections at Edom Prom (Schiaparelli crater) from time to time, even when spacecraft imagery shows no clouds in the area; but there doesn’t seem to be anything about the geology that is unusual, as you and I have remarked in our conversations.

Hope everything is going well with the 2020 rover!

Best,

Bil
Text from chapter 5, “Mars above there dreaming spires”:
On the night of December 8, 1951, a leading Japanese planetary astronomer, Tsuneo Saheki of the Osaka Planetarium, was examining the tiny 5.3" disk of Mars through his 20-cm Newtonian reflector, with a magnification of 400x, when he noted a “very small but extremely brilliant spot,” which suddenly appeared at the eastern end of the small dark spot known as Tithonius Lacus. It remained visible for five minutes, with a brightness surpassing that of the north polar cap, and twinkling like a star. It then began to fade; ten minutes after it first appeared, it was “only a common white cloud near the limb,” and a half hour later he could make out no trace of it.

Saheki’s observation created quite a stir, eliciting a flurry of comment and speculation. A meteorite impact seemed like one possibility, and could not easily be ruled out. It would produce both a flash and a cloud of ejecta debris. More farfetched, but widely publicized at the time, was the idea that an atomic bomb had been exploded on Mars. (Recall that in 1951 memories of Hiroshima and Nagasaki were still fresh, particularly in Japan, and ever-more powerful nuclear weapons were being tested at a feverish pace by the US and USSR on remote atolls in the Pacific and on the Arctic island of Novaya Zemlya. Saheki rejected this interpretation, and instead leaned to the opinion that he had likely observed nothing more than a reflection from ice on a mountainside--though he hastened to add that this explanation could not explain the formation of a cloud just after the flash was observed. (The flash was observed far from the subsolar point, the location on Mar where the Sun would appear at the zenith, which immediately ruled out specular reflection from brine pools or a sheet of ice, ideas that were also considered.)

Bill Sheehan (flagstaff, AZ)

¤·····Subject: RE: Mars 8 November 2018 1657UT RGB and IR.

Received: 9 November 2018 at 15:37 JST

Hi all,

Mars image set from last night in rather poor conditions, which were deteriorating further, preventing any view of the Arsia Mons cloud.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181108/CFs08Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars 2018/11/08-Kumamori

Received: 8 November 2018 at 23:30 JST

Mars images on 8 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181108/Km08Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars 2018/11/07-Kumamori

Received: 8 November 2018 at 12:15 JST

Mars images on 7 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181107/Km07Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars　M181107 ishibashi

Received: 7 November 2018 at 23:17 JST

Mars images on 7 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181107/Is07Nov18.png

Tsutomu ISHIBASHI (Kanagawa, JAPAN)

¤·····Subject: Mars 2018/11/06-Kumamori

Received: 7 November 2018 at 12:10 JST

Mars images on 6 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181106/Km06Nov18.png

Teruaki KUMAMORI (Osaka, JAPAN)

¤·····Subject: Mars 4 November 2018 1655UT RGB and IR. 1750UT RGB

Received: 7 November 2018 at 03:14 JST

Hi all,

I had an extended session (16.50-19.25UT) on 4th November with the intent of trying to follow the development of the Arsia Mons cloud from early(Mars) morning until later in the day.

Unfortunately the seeing conditions, particularly at B wavelengths, was not as good as the 3rd November, and it was difficult to detect the cloud.

Attached two image sets from the session. I did not take an IR for the second set.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181104/CFs04Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Mars: November 5, 2018

Received: 6 November 2018 at 12:57 JST

Hi ,

I have attached my images of Mars November 5, 2018 at 0:11 UT and 0:31 UT.

Thanks,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181105/FMl05Nov18.png

Frank J MELILLO (Holtsville, NY)

¤·····Subject: Mars images - November 4/5

Received: 6 November 2018 at 05:18 JST

Gentlemen,

Seeing was above average (3/5-4/5) for the first time in over a month. Transparency was poor. There was an even layer of thin clouds. Local transit was at 23:42UT.

Regards,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181104/PGc04Nov18.png

Peter GORCZYNSKI (Oxford, CT)

¤·····Subject: Saturn image (May 8th.)

Received: 6 November 2018 at 02:44 JST

Hi all,

Here is an image from May 8th in good seeing.

http://www.damianpeach.com/barbados18/s2018-05-08-0725_9-RGBdp.jpg

Best Wishes

Damian PEACH (Selsey, WS, the UK)

http://www.damianpeach.com/

¤·····Subject: Mars images on 5 November

Received: 5 November 2018 at 21:47 JST

Mars images on 5 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181105/Ak05Nov18.png

Tomio AKUTSU (Ibaraki, JAPAN)

¤·····Subject: Mars images - October 19

Received: 5 November 2018 at 01:17 JST

Gentlemen,

I finally got around to processing these images. Seeing was poor (2/5). Transparency was very good with a low dew point.

Regards,

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181019/PGc19Oct18.png

Peter GORCZYNSKI (Oxford, CT)

¤·····Subject: Jupiter images (May 7th.)

Received: 4 November 2018 at 21:58 JST

Hi all,

Here are some Jupiter images from May 7th. Some excellent seeing at times.

http://www.damianpeach.com/barbados18/2018-05-07-0328_8-RGB.jpg

http://www.damianpeach.com/barbados18/2018-05-07-0526_9-RGB.jpg

http://www.damianpeach.com/barbados18/2018-05-07-RGB01.jpg

http://www.damianpeach.com/barbados18/2018-05-07-RGB02.jpg

http://www.damianpeach.com/barbados18/2018-05-07-RGB04.jpg

http://www.damianpeach.com/barbados18/2018-05-07-RGB05.jpg

Best Wishes

Damian PEACH (Selsey, WS, the UK)

http://www.damianpeach.com/

¤·····Subject: Mars images on 3 November

Received: 4 November 2018 at 20:52 JST

Mars images on 3 November 2018.

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181103/Ak03Nov18.png

Tomio AKUTSU (Ibaraki, JAPAN)

¤·····Subject: Mars 3 November 2018 1731UT RGB and IR. Arsia Mons linear orographic cloud

Received: 4 November 2018 at 15:59 JST

Hi all,

Clear skies and some decent seeing last night, following a cold front that had moved through the last couple of days, that had prevented imaging.

The linear cloud emanating from Arsia Mons can be seen most clearly in B, to a lesser extent in G and also just visible in RGB.

Solis Lacus at upper left and Olympus Mons lower right, below the cloud.

Best regards, Clyde

http://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2018/181103/CFs03Nov18.png

Clyde FOSTER (Centurion, SOUTH AFRICA)

¤·····Subject: Arsia Mons linear orographic cloud. 3 November 2018 1733UT B.

Received: 4 November 2018 at 14:51 JST

Hi all,

I had some decent conditions last night after another cold front had moved through the last few days(cloud unfortunately prevented imaging).

Although I could not see anything on screen, as soon as I started processing the B images, the linear cloud emanating from Arsia Mons, and reported by the Mars Express team, was very evident.

I will circulate the full image set in due course, but thought this was of interest.

Best regards, Clyde

Clyde FOSTER (Centurion, SOUTH AFRICA)