Lunar Sketch 12 of 12: Vieta

Hi All,

I hope you and those close to you are keeping well.It is great delight that I am posting my 12th installment of my lunar sketches - I've also created a collage of all 12 sketches - see attached images. As some of you might recall I started this project last year when the plan then was to sketch a lunar feature each month for 12 months. While I was unable to sketch a lunar feature during August and December, I am happy to have completed 12 sketches over the course of a year.

The main aim of the project was to learn about the Moon. And while I've only scratched the surface - pun intended - I have come away with knowing a little bit more about our closest celestial neighbour. What's more, I have thoroughly enjoyed reading through the comments and feedback that many of you have be so kind to offer over the past year. Your posts have been a great source of encouragement, particularly your ones Aubrey, and your recommendation to buy Rukl's Atlas of the Moon was a great piece of advice.

In terms of the the final sketch, I decided to go for 'Vieta'. While the conditions were not great last, this crater stood out. I was struck by the triangular shaped shadow that was being cast from Eastern crater wall, and much of the crater floor was covered in darkness. In saying that, I did see some sort of feature in the center of the crater. Having checked Rutk's Atlas it seems that it may have been a smaller crater. At 139X it appeared more like a rocky outcrop though.I did try to push the magnification to 208X, but with poor seeing and transparency last night 139X was about as far as I could go.

In addition to 'Vieta' crater, 'Fourier', and a series of craterlets North of 'Fourier' were observed. Fournier displayed a more circular shape, and did not seem as deep as 'Vieta'. And those craterlets were notably smaller than Vieta, but provided me with an idea of its size. According to my Virtual Moon Atlas, the smallest craterlet, which is Fournier 'G' is only 11km in diameter - eight times smaller than Vieta!

Other details from last night's session include:

Location: Dundrum - Bortle 8
Instrument: f/5 250mm Newtonian Reflector on a Dobsonian base
Seeing: 3pk
Transparency: 2
Time: 20:36 - 21:11 UT

As always many thanks for taking the time to read the above, and your comments and feedback are always welcomed.

Clear skies to all,
Darren.

Hello, Darren. 

Once again I very much would like to thank for your 12th lunar sketch. It is indeed an excellent one of the 87 km crater which is called Vieta. I see it on Map 51 in Rukl alright. What a real treat to notice those super shadows which I reckon is a double shadow - one dark and one quite grey. I am also admiring the satellite craters which you have dotted around Vieta. 

I see in Rukl's Atlas Monsieur Francois Viète was both a lawyer and a mathematician who lived from 1540 to 1603. So he even predates Galileo. I wonder how life was during those many years ago. Answers on a postcard for that one!! 

Thankfully I have observed the Vieta at some time in the past, Darren. There is also a very strange looking crater Palmieri which I also observed very recently and it is near Vieta but Rimae Palmieri was hidden from me at the time. 

Clear skies from Aubrey.  

Hi Aubrey,

Very many thanks for your kind message.

When observing the crater I thought there was a slight difference in the colour of the shadow on the crater floor. That may have been caused by the cloud cover though!

It always amazes me when I think about the number contributions that individuals such Vieta made during those early days of astronomy. Could you imagine what they would do with the instruments we have today!

I did not notice that other crater you mention; but based on where it is located I reckon Palmieri was pretty much washed out. From Rukl's Atlas of the Moon it seems to have a teardrop shape to it. I must try to observe it at a later date. This is one of the things I love about the Moon: there is always something interesting to look at.

Clear skies,

Darren.

Hi Aubrey,

Very many thanks for your kind message.

When observing the crater I thought there was a slight difference in the colour of the shadow on the crater floor. That may have been caused by the cloud cover though!

It always amazes me when I think about the number contributions that individuals such Vieta made during those early days of astronomy. Could you imagine what they would do with the instruments we have today!

I did not notice that other crater you mention; but based on where it is located I reckon Palmieri was pretty much washed out. From Rukl's Atlas of the Moon it seems to have a teardrop shape to it. I must try to observe it at a later date. This is one of the things I love about the Moon: there is always something interesting to look at.

Clear skies,

Darren.