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

@markmccaughrean What do you mean by the bright limb at lower-left?
@saarmuller I mean that that's a typo – the limb at lower-right. Ugh – will edit.
@markmccaughrean Sorry for the pedantry, but isn't it "limn"? Happy to be wrong if there's another use of "limb" that I'm misunderstanding here.

@monotremata “Limb” is the term used for the edge of a planet or moon in astronomy:

https://dictionary.obspm.fr/index.php?showAll=1&formSearchTextfield=limb

“Limn” is arguably a related term, although whether it actually is, etymologically, I’m not sure: one of its meanings is to “outline or delineate with light”:

https://dictionary.obspm.fr/index.php?showAll=1&formSearchTextfield=limb

An Etymological Dictionary of Astronomy and Astrophysics - English-French-Persian

@markmccaughrean Wow, thanks! I'm glad to learn a new term!