Lunar 100 observing report 29.7.2010

[Doc]

29.7.2010

Meade Lightbridge 16" F4.5 FL 1829mm

Slightly cold night, some dew appeared.

Lunation 18.09 days

Illumination 87.2%

Phase 318°

Started obsedrving 23.00

Nummber 48 Cauchy region Fault, rilles, & domes

Had a look around the area of Cauchy on the eastern shores of Mare Tranquillitatis, saw the Rima Cauchy through my 6mm ortho at x 304 it's 127 miles long and just 2 miles wide and very hard to spot, also there are numerous little craters and domes situated around the Crater Cauchy itself, a very interesting area of the moon.

Number 20 Posidonius Floor-fractured

On the eastern side of Mare Serenitatis sits the fantastic looking crater Posidonius, in my mind it looks oval in shape but according to VMA it's actually circular being 58 miles in diameter, it's height is unknown. This crater comes from the Upper Imbrian period in the moon's history which makes it approximately 3.6 billion years old. Through my trusty 9mm ortho I could detect higher walls on the eastern side and the lovely 13 mile diameter crater J cutting into Posidonius northern rim. There is a crater just of centre within Posidonius and with the 4mm Uwan inserted giving x 457 I could just detect with averted vision three formations surrounding the centre crater.

Number 21 Fracastorius Crater with subsided & fractured floor

On the Southern shores of Mare Nectaris lies the lovely crater Fracastorius, this is a lave filled crater 75 miles in diameter. The northern walls are missing swallowed up by the lava but steep walls can be seen on the eastern side. I decided to count the craters on the floor of Fracastorius and with the 9mm ortho giving x 203 I managed 3 craters with fracastorius L being the biggest at 3 miles in diameter. With the 6mm inserted I could see a further two bringing the total to five. With this eyepiece I could detect a few darker lines going accross the crater's floor were these the fractures I was meant to find, if so they were very hard to spot.

Number 34 Lacus Mortis Strange crater with rille & ridge

Next up to a very old crater VMA states at least 4.3 billion years old it is called Lacus Mortis and is 91 miles in diameter and has a very uneven shape. It contains the crater Burg which was very easy to see, but through the 6mm at x 304 I could detect many rilles running accross Lacus Mortis crater floor, a very pretty view and these wrinkle ridges really stood out.

Number 33 Serpentine Ridge Basin inner-ring segment

Just to the west of Posidonius is a north to south wrinkle ridge known as the Serpentine Ridge and also by the name Dorsa Smirnov, it is quite long at 79 miles and VMA states 12 miles wide. The libration was not ideal but the 6mm ortho easily picked it up and I travelled the whole distance of the magical ridge, I came accross a little crater about halfway up the Serpentine's length just before the kink known by the strange name crater Very, and is only 3 miles in diameter. If you follow it towards the southern end it joins up with many rilles but these were extremely hard to see.

Number 40 Janssen Rille Rare example of a highland rille

There is so much going on in this area of the moon, I located the crater via the two craters Fabricius and Metius, Janssen lies just south of these two craters. Janssen is very old and deformed and has numerous craters inside and outside it's walls. I could detect the series of ramified rilles inside the crater with my 6mm ortho.

Number 41 Bessel Ray of uncertain origin near Bessel

Situated on the Mare Serenitatis not far from the Serpentine Ridge is a strange looking bessel ray. With the 9mm ortho inserted I could see the white stripe accross the mare's floor which shows the ray cutting through the crater Bessel and heading towards the crater Menelaus but I could not work out where this ray originated from.

Number 18 Mare Serenitatis dark edges Distinct mare areas with different compositions

Staying in the area of Mare Serenitatis I went hunting for the dark edges around the southern shores of the sea. Through the 9mm ortho I could easily detect the dark edges in the area known as Dorsa Lister, they carry on for quite a long way round the outer rim of Mare Serenitiatis.

Number 90 Armstrong, Aldrin & Collins Small craters.

The best of the night was next, I studied this area for over 1 hour and it was fantastic, I could easily see the crater Armstrong at 3 miles in diameter it wasn't hard, Collins was alot harder and I had to insert the 4mm Uwan and after alot of trying I finally spotted Collins with averted vision, this crater is alot harder at 2 miles in diameter, the strange thing is once spotted I could then detect it quite easily with normal vision. The third crater of this trio was really hard, Aldrin lies amoung many very faint features and I think I spotted this but cannot be 100% sure but I'm sure I saw the occasional glimpse when viewing allowed.

While searching and observing this fantastic area I looked at the landing areas of Surveyor 5 and Ranger 8. On September 8, 1967 Surveyor 5 was launched and landed on September 11, 1967 not far from the crater Collins on the Mare Tranquillitatis, 19049 images were sent back to Earth and we finally lost communication on 16th December 1967. I then moved down to the Ranger site, this was launched on the 17th Feb 1965 from Cape Kennedy and sent back 7137 photographs.

But it is more famous for Apollo 11, the first mission to land a man on the moon. It was launched on a Saturn V rocket at at 9.32am local time (EDT) on July 16, 1969 from Pad 39-A from Kennedy Space Center, Florida, USA. It was the fifth manned mission in the Apollo Program. It landed very close to the three little unamed craters which were later named after the astronauts.

Number 53 Lamont Possible buried basin

Not far from the Ranger 8 landing site and the crater Arago I could see the ghost crater Lamont, you could just make out the walls of the crater and maybe a central peak, which is now lava filled and almost invisible.

32 Arago Alpha & Beta Volcanic domes

Just to the right of Arago is two white patches which are the volcanic domes Alpha and Beta Arago, easily seen and distinguished in the 9mm ortho, a very pretty sight and one that would finish the nights viewing just perfectly.

[bish]

That was a good nights observing and great report. I don't know how long the Lunar 100 has been around but I've only recently come across it and realised how little of the Moon I've actually identified. I only saw the straight wall recently and have been observing for 3 years. There's so many interesting things to look at on the Moon I should make the effort to observe it more often.

[barkis]

A very interesting project this Mick. It takes a dedication and patience I don't possess, although I love lunar observing.

I tend to just wander around muttering Wow occasionally.

I was out with the 12" sct early am Thursday, just cruising up and down the terminator at medium powers. Fascinating sights.

I always prefer the waning shadows for reasons I can't explain.

As usual though, my visit was brief due to cloud taking a hand.

Ron.

[johnkirkpatrick]

Great read, very detailed report.

[Jamie]

A very thorough and well thought out report Mick.

I have never taken the time or effort to do this, maybe its time i did.....

Thanks for posting.....

[BAZ Senior]

Excellent report Doc.

I didn't finish work until 11.30, and had to get up at six on Friday, I was tempted, but I wouldn't have got my head off the pillow!