Vallis Schroteri on the Moon -2/01/15

Good evening, all. Valerie and I have just come in from observing an 11 day old Gibbous Moon.

Near the terminator, we observed at 112X Vallis Schroteri coming out north of the crater Herodotus. It is shaped like a snake's head. The brightest crater on the Moon -Aristarchus was also present. We could see the Agricola Mountains and for the 1st time: an observation of Mons Herodotus which is 5 kilometres wide. I cannot find out its height though strangely. Still, the sight included the excellent plateau surrounding the whole area.

My guidescope has a 6 degree field of view at 11X. And I could easily fit in the bright star Aldebaran east of the Moon.

Then the haze got too thick -so we called it a night.

Thank you for reading -its my 1st night of 2015. Happy New Year, everyone.

Aubrey.

Hi Aubrey

I have just today completed an exercise for a course whereby you calculate the hight of lunar features from their shadows. What time did you observe Mons Herodotis and I will try calculating the height and compare it once we find it?

What's the most detailed Lunar Map that you are aware of? I am looking for the depth of the crater that sits within Descartes and the best I can find is a lunar topography map showing between 2 & 4 km?

Thank
Kevin

Wow, Kevin! This is a surprise.

I was observing Mons Herodotus between 20 UT and 20.30 UT. You must be clever at mathematics and geography.

The only maps I use is Antonin Rukl's Atlas on the Moon. Is it the crater Descartes A that you are wondering about? Or is it Descartes C? I cannot find any information on either on Google. Sorry, Kevin. Discovering the depths of craters outside Rukl's book is very difficult to attain.There is another book I have heard about. It is the Cambridge Atlas of the Moon. Some amateurs think it is the best.

Many thanks, Kevin.

Aubrey.

Hi Aubrey

Don't need much mathematics and it’s probably more important to observe and sketch to scale. I am currently getting around a 95% accuracy if done properly close the terminator and along the lunar equator.
I calculated the height of Mons Herodotus at 1.59 Km but there are so many wild assumptions in there that I am surprised it’s not further off and very difficult to determine the right shadow length unless you do it properly when observing (I used Moon Globe set get the shadow at the time of your observation and I find the contrast can be a little off). I did actually find an estimated height from an Apollo 15 image and funny enough the height is estimated by the length of the shadow at 1200m. the-moon.wikispaces.com/Mons+Herodotus recent exercise.

Here is my image still on the drawing board from yesterday which I took a photo of and inverted it so you can see the detail. I can share the mathematical formula and exercise if you like as its really easy using a few distances and angle to the sun. Calculating the height of the southerly peak (can’t find a name for it) on Montes Caucasus was a treat and its estimated that the highest peaks are at 6km and I calculated the peak at 5.64km high but I see that the third peak's shadow is a little longer so I think I am about right.

Thank you, Kevin, for providing me with this information. Let me make sure you know where Mons Herodotus is positioned. It is about 50 kilometres south of Montes Agricola. I am only making sure that you are aware it is not near Montes Caucasus.

Please do continue your research. Perhaps the mountain is 1.6 Km high. That seems feasible to me.

I did very much enjoy seeing it on Friday night for the 1st time.

Aubrey.

Yes that’s the one, If you follow the URL it will take you to the Apollo image of it. I only added the Caucasus drawing to show you what I have been doing on the feature heights for some fun - when I do the same exercise for Mons Herodotus it comes out at 1.56km high using some estimations but I believe that they have measured from the same photo in the URL that the height is actually around 1.2km.