Sirsalis Rille

[Mark at Beaufort]

I have been following the Lunar 100 for over 7 years and one object I have not observed, for one reason or other, is the Rilles around the crater Sirsalis. The general advice is to observe on the 12th day, which is today.

I set up the Orion VX8 with the TeleVue 8-24 zoom together with a Baader 2.25x barlow and a Polarising filter and viewed the area.

I could easily view the Rille across the whole length as shown in this SVS NASA Moon Phase and Libration website for tonight. The Rille stretches from De Vico past Cruger and onto Sirsalis.

Well worth a look tonight because this is the best day to observe this Rille.

[mikeyj1]

Congrats on your achievement, that's preservation!

[cardigan wearer]

Ok I had to Google it but tonight I discovered what a Rille is. And of course tonight is perfectly clear because I sold my old ETX 125 on ebay and posted it today. So thanks to my usual luck expect a clear sky until I buy my retirement present in 2 weeks (end of January)

[John]

Nice report Mark and thanks for the "heads up" on this interesting area of the Moon.

I can make out quite a bit of the rille with my ED120 tonight at 257x. We have thin high cloud patches here tonight and when those cross the Moon the rille is not resolveable with my scope.

It's quite challenging recognising features so close to the limb because of the foreshortening effect. 

 

 

[Astro Imp]

Nice report and congratulations on completing the lunar 100. I have been working my way through the list and seem to be stuck on 85 completed but intend to carry on.