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Ursa Astronomical Association

Mons Gruithuisen Gamma ja Delta - 17.10.2021 at 00.39 Porvoo, Sondby Observation number 101819

Visibility III / V

Jorma Koski, Ursa (Helsinki)

When the Moon finally came out of the cloud after midnight, I punched a picture of it on a peg. As Teemu Öhman said in his blog (, today - on International Moon Observation Night - there was an opportunity to spot two strange sour volcanoes in the terminator, Mons Gruithuine’s Gamma and Delta, and they appear as dim spots next to Sinus Iridium. #InOMN

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  • Observation target
    • Moon surface feature
  • Name of the observation target
    • Mons Gruithuisen Gamma ja Delta
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