Contact information

Ursa Astronomical Association
Kopernikuksentie 1
00130 Helsinki

Ursa Astronomical Association

Bailly - 16.3.2022 at 22.00 - 16.3.2022 at 22.15 Vantaa, Pähkinärinne Observation number 105250

Visibility IV / V

Paula Wirtanen, Ursa (Helsinki)

Bailly Crater is located on the southwestern edge of the Moon in the libra area. At its worst, the northernmost parts of it may be visible, but when the southern libra is great, you can see it completely and the Hauseck , which is visible from behind, may then be in the field of view.

Bailly is named after Jean Sylvain Bailly , a French astronomer and politician. He should not be confused with the British Francis Bailyy (with one L) born a little later, who is remembered for Baily’s pearls associated with complete eclipses. Francis Baily got its name from the surface of the Moon on the isthmus between Mare Frigori and Lacus Mortis - that is, on a completely different side of the Moon.

JS Bailly had the misfortune of living during the French Revolution and so his life ended at the age of 57 on the guillotine while he supported constitutional monarchism.

Bailly is round in shape, 300 kilometers in diameter. However, due to its location on the edge, it looks very flat when viewed from Earth. Even with a small telescope, that can be distinguished, but it is difficult to study the details. Seeing was at the borderline of mediocre and inadequate at the time of observation, and much more detail can certainly be visually distinguished from Bailly than in my own drawing.

At the bottom of Bailly, the satellite craters Bailly A and Billy B on the edge stood out, Bailly B quite bright. The ridges and small craters on the west side of the base were visible only in vague pits, and the hole in the rampart on the edge of the crater is probably the shadow of Hausen in the back, with the Moon Terminator just passing by Bailly.

Of the Zucchius, Bettinus, and Kircher craters above Bailly, I did not distinguish at all in detail, only the shadows and brightness of the edges. These craters as well as Bailly almost completely in the shade stand out better in the photo I took the day before.

#Lunar100: 037 Bailly

Additional information
  • Observation target
    • Moon surface feature
  • Name of the observation target
    • Bailly
  • Seeing
    • Average
Technical information

Sky-Watcher Skymax-127 (M127 / 1500) & SP 10 mm (150x).

Send a comment

Comments are checked and moderated before publication If you want to contact the observer directly about possibilities to use these images, use the Media -form.



characters left

By sending in this comment I confirm, that I've read and understood the the observation system's privacy policy.