ISS transits the Moon!

By Phil Plait | November 17, 2009 7:30 am

German amateur astronomer Bernhard Christ was in the right place at the right time — due to very careful planning and foresight — and captured this astonishing scene:


[Click to embiggen.]

That’s the International Space Station crossing the face of the Moon, what astronomers call a transit (like an eclipse, but when something small goes in front of something big). This image is actually a composite of several images taken in a row, with some sharpening to make it cleaner looking.

The transit only lasted for 0.4 seconds, so Christ had to be on the ball to capture this. He used a digital astronomical camera that can take what is essentially video (really just rapid still shots, but after all that’s what video is), and processed the individual frames. It’s a gorgeous image, with the Moon looking really stunning.

And if you’re wondering why he only got four shots of the ISS, look again: there is a shot of it just inside the limb of the Moon, but it’s low contrast and hard to see. Just follow the path of the ISS as it crosses the Moon and you’ll find it.

My thanks to Herr Doktor Christ for allowing me to post this picture. Well done, and vielen Dank!

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
MORE ABOUT: ISS, Moon, transit

Comments (39)

  1. This image is actually a composite of several images taken in a row

    I’d hope so, given what we’re seeing. o.o

  2. Ryan The Biologist

    Wow! Very impressive work!

  3. “Herr Doktor Christ”

    If in German, then it needs to be in the dative case: Herrn Doktor Christ. :-)

  4. Fancy! I love shots like this!

  5. cancer monkey

    In that picture it almost looks like the ISS is SMALLER than the moon! Crazy optical illusions!

  6. @Phillip Helbig: Accusative case, not dative case. 😉

  7. Charles Boyer

    This is awesome photography — if you know much of the art and science of what Christ had to do to take take this, then you are undoubtedly very impressed. Sure, computer controls make it easier (read: possible) but even then, every thing has to be just-frakkin-so or you miss the moment.

    Considering the moon is a moving target on multiple planes relative to a stationary camera, and that the ISS is rapidly transiting, this is the sort of thing that makes me really say “WOW!” out loud.

  8. Another cool thing about this photo (as if more were needed!) is the way it gives some scale to the ISS. I know how big the angular diameter of the moon is when I see it in the night sky – now I have an idea of how tiny the ISS is whenever I see it go over. Fantastic!

  9. lagomorph

    Christ that’s impressive!

  10. Mchl


    I like how solar panels are directed towards the Sun.

  11. Levi in NY

    “Hooray for Christ!”…says the atheist.

    (BTW, he’s German so his name rhymes with “fist”, not “diced”)

  12. Steve Paluch

    That is really cool. Thanks for sharing, Phil. Took me awhile to find the low-contrast frame. 😉


  14. Wait, the ISS looks sort of fuzzy and out of focus! I am doubting its existence. 😛

    Wow, imagine that, using science and math to predict something (i.e. this transit)! Funny how that works!

  15. I have to wonder if being a fan of Christ makes one a Christian, and if so what that would imply?

  16. TSFrost

    Well, I’M wondering how many Christians will end up here from Google because of all the Christ dropping.

  17. Chip

    ISS? Looks to me like the spaceship from Forbidden Planet! 😉

  18. FdelV

    I doubt that photo is possible. My intuition and experience with pictures of the moon tells me that the moon and ISS need completly different exposures. The moon is so bright compared with anthing else (except the sun), that is not possible to see detail of the ISS with the moon behind.

  19. Really an awe inspiring picture. Thank you for posting it

  20. Photoshop! This is obviously an edited photograph because I’ve seen several photoshop jobs in my time and this one is really blatant.

    P.S. Sarcasm!

  21. So, Christ took this picture? I wonder what camera Christ used for this heavenly shot?

  22. Lars Bruchmann

    I’d think the exposure would be F3.16… LOL.

  23. Sili

    I actually thought I saw the ISS today while waiting for the train (I’d misread the schedule), but from Heavens Above I can see that it should be visible today.

    I did think it was moving too slowly, but then it seemed to blink out as it passed to the East.

    ETA: not an Iridium flare either. Anyone know where/how I can check what might have passed there? (Assuming it was celestial and not a plane – it didn’t remind me of one.)

    I was around 56.4°N, 9.8°E looking South(ish) around 18:00 (ECT). I’m not good with the constellations, but it was directly opposite the Big Dipper. It came from West (but I don’t know for how long) and blinked out about two fist-worths further East.

  24. Damn, this guy had such a good weather there in Rüsselsheim? I live just about 100 km north of his place and I had rain and dense clouds for weeks. I didn’t even see the moon for two weeks… :(

  25. 13. kuhnigget Says:


    Why do I feel like you must have a ‘BatBoy’ shirt? 😉

    Okay… here it is:

    That’s no moon…, oh, wait… it is…..


  26. Petrolonfire

    Thank Christ for that! 😉

  27. csrster

    Fdelv: I would suggest that you experience and intuition are completely misguided. The moon has a famously low albedo, while the ISS is made of shiny stuff. I would therefore expect the ISS to have considerably _higher_ surface brightness. However as they are both being illuminated by the same Sun I would expect that photographing them together wouldn’t be any harder than photographing any other high-contrast scene in bright sunlight, something that modern digital cameras are quite good at.

  28. 19. Chip Says: “ISS? Looks to me like the spaceship from Forbidden Planet!”

    If in Geek, then it needs to be in the dative case: C57-D

    – Jack

  29. Tony

    When was this taken? There’s been no moon over Europe for a few days.

  30. Beasjt

    I want a name like that so I can also make pictures like that.

  31. Norman Weingart

    What a great bit of photography. When I first saw the picture I thought there was a hummingbird crossing in front of the lens…

  32. GregInVancouver

    I’m sorry but I can’t help hearing the Blue Danube Waltz whilst looking at this image.

  33. Plutonium being from Pluto

    Another photo of the ISS against the Moon – not as good but still quite nice is linked here via the BA blog :

    Wonder if these will make the BA’s best of 2010 pictures list?

    My all-time fave though would have to be this one of the International Space Station and space shuttle which made no. 5 on the BA’s Best Astronomy Pictures of 2006 list :

    & in colour & the original version (I guess) :


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


See More

Collapse bottom bar