Contact information

Ursa Astronomical Association
Kopernikuksentie 1
00130 Helsinki

Ursa Astronomical Association

Mare Crisium - 4.5.2022 at 21.50 - 4.5.2022 at 22.05 Vantaa, Pähkinärinne Observation number 106643

Visibility IV / V

Paula Wirtanen, Ursa (Helsinki)

The rising crescent moon was reasonably high in the western sky after sunset. I started the observations well in advance before the sickle dropped unnecessarily low. Yes, you notice the early twilight, the background sky was clearly blue and the contrast was not as good as when you saw the darker Moon. However, the seeing was quite reasonable.

Mare Crisium was nicely displayed, especially on its western edge with suitable shadows. The Yerkes, almost ghostly on the surface, stood out clearly, as did the Yerkes E and the strain between them. Under suitable lighting conditions, these sometimes resemble a pattern reminiscent of flying Kotka when the object is looked downwards. However, Yerkes E stood out so strongly that there seemed to be an extra "vortex" in the wing of Kotka. The pimples to the north of the Yerkes E also stood out well under these lighting conditions.

There are also ridges at the bottom of M. Crisium, Dorsum Oppel stood out very clearly from these, I didn't see any other ridges despite the reasonably good seeing. It’s worth noting that the Dorsum Oppel appeared light, even though I’ve marked it as a line in the drawing.

Promontorium Olivium and Lavinum on the western edge of M. Crisium were very clear and sharp. This is a place that looks like a cohesive bridge in some lighting conditions, now those headlands stood out so clearly that no bridge could be obtained from it, even with a vivid imagination.

The eastern edge of the Mare was left unfinished for a while, as the seeing suddenly began to deteriorate and, oddly enough, its details were no longer separated. It's just that I didn't expect a darker sky, but now I was able to explore the area at a slightly higher magnification under comfortable lighting conditions.

#Lunar100: 010

Additional information
  • Observation target
    • Moon surface feature
  • Name of the observation target
    • Mare Crisium
  • Seeing
    • Good
Technical information

Sky-Watcher Skymax-127 (M127 / 1500), SP 6 mm (250x).

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.