Post B4vnCD0sNCDZCeUya8 by markmccaughrean@mastodon.social
 (DIR) More posts by markmccaughrean@mastodon.social
 (DIR) Post #B4vnCD0sNCDZCeUya8 by markmccaughrean@mastodon.social
       1 likes, 5 repeats
       
       You'll likely catch this image a million times in your various feeds: Earth as seen by Reid Wiseman from Artemis II en-route to the Moon.My first thought? That's *really* noisy 🧐But then I realised – it's the *nightside* of Earth, illuminated by the almost full Moon, not the Sun 🌕The bright limb at lower-right is where the dayside starts, & the fact that you can see aurorae, airglow, & cities in Europe, Africa, & S & N America also gives the game away. Cool.#Photography #Artemis
       
 (DIR) Post #B4vnCDZcI20UwOkijQ by markmccaughrean@mastodon.social
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       Two planets for the price of one 🙂This screenshot from Celestia is pretty close to the orientation of the #Artemis II picture taken of Earth's nightside.The stars in the background line up pretty well, & as @Nina_cried suspected, the bright object to the lower-left of Earth is Venus 👍And as the original shot suggests, the Sun is behind Earth, slightly to the lower-right of centre, hence the bright dayside limb there. #Space
       
 (DIR) Post #B4vnCDy4p5ZaAGCFrE by markmccaughrean@mastodon.social
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       I tried getting Astrometry.net to solve for the starfield first, but it failed (perhaps not surprisingly given the stupid big planet in the way).So I went into Celestia, set the time to a reasonable guess for when the Artemis picture might've been taken (I ended up at 00:30 UTC last night), played with the orientation, & bingo – everything lines up.Not completely perfect, but good enough for government work.
       
 (DIR) Post #B4vnCEbQSn348IbgBs by markmccaughrean@mastodon.social
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       Ha – I promise I didn't check before fiddling in Celestia, but I see that the EXIF information in the original Artemis JPG says it was taken at 00:27:39, presumably UTC.And putting that time into Celestia, I get a sub-latitude of -2.8º, a sub-longitude of -13.9º, and a distance of ~10,000km from the surface of Earth.Which is niche information unless you're a planetary aurora specialist like Jonathan Nichols, who asked 🙂
       
 (DIR) Post #B4wbb7rFflPMA74Vd2 by rick@a.n0id.space
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       @markmccaughrean ohhhh thats why! O.OI was wondering myself yesterday, why i see electricit light from big settlement if they are in daylight
       
 (DIR) Post #B4wejlKv4m8imWl5gu by edgeofeurope@mastodon.social
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       @markmccaughrean I wonder what this is, just above and to the right of the center. A reflection of the moon in the sea?
       
 (DIR) Post #B4wejlba4pT1cCYOf2 by aetios@sns.minovsky.space
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       @edgeofeurope @markmccaughrean it's the inside of the window
       
 (DIR) Post #B4wgmcGFTSeHPc3uqW by markmccaughrean@mastodon.social
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       @rick 🤔😊👍