Unnamed rille near Rupes Recta

直壁附近不知名小月溪

9月14日日出前1小時拍的，受惠於香港的低緯度，當時月亮近天頂位置，視寧度十分理想。所以我嘗試超指標的加個2x巴羅透鏡用f/22拍攝。很訝異在2微米像素相機以11x焦比下，能夠拍下一條跟直壁呈直角的不知名小月溪。1972年，香港太空館創館館長廖慶齊先生於其香港上水自家天文台拍攝的同一區域獲得美國天文聯盟主協的天文攝影比賽冠軍，評委認為從未有人試過能拍得如此清晰的伯特月溪。他的作品及自家天文台更於1974年4月榮登「天空與望遠鏡」雜誌封面專題。很幸福的是，我們今天在數碼科技助力下，月面上比這更細小，僅一兩百米尺度，只能從月球勘測軌道飛行器照相機影像或Google Moon上才有的小地貎也不難拍下來了，當然也是因為這個天文台選址在吐露港及船灣淡水湖畔，地理十分優越，讓高解像度天文觀測得以實行。

This image was took on Sep 14 and hour before Sun rise, when the Moon was near zenith here in Hong Kong, thanks to the rather low latitude. Seeing was very good, so I tried shooting at f/22 with a 2x barlow on, I am surprised that at higher than suggested focal ratio, at f/22 with this 2um pixel camera or 11 times the pixel size, I am able to capture the very faint unnamed rille perpendicular to Rupes Recta. In 1972, Mr. Joseph Liu, the founding curator of the Hong Kong Space Museum, captured images of the same lunar region from his private observatory in Sheung Shui, Hong Kong, and won champion in the astrophotography competition organized by the Astronomical League of the United States. The judges remarked that no one had ever succeeded in photographing the Birt Rille with such remarkable clarity. His work and private observatory were later featured on the cover story of Sky & Telescope magazine in April 1974. Fortunately, with the aid of modern digital technology, even finer lunar surface features, on scales of only one to two hundred meters and only appear on Lunar Reconnaissance Orbiter Camera images or Google Moon, can now be captured with ease. This was also made possible by the observatory’s advantageous location on the shores of Tolo Harbour and the Plover Cove Reservoir, which provided excellent environment for carrying out high-resolution astronomical observations.

方社長攝於星河科研社大美督天文台

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Photo: Savio Fong Director of Galaxy Scientific Group

Celestron EdgeHD14 telescope

SkyWatcher EQ8R Pro eq mount

ZWO ASI678MM camera

Carl Zeiss Abbe 2x Barlow

Astronomik ProPlanet 642 BP filter

Galaxy Scientific Group Tai Mei Tuk Observatory

For inquiries about stargazing activities, please WhatsApp us at https://wa.me/85298119630

Reference:

Lunar Reconnaissance Orbiter Camera images, 

Google Moon image,