Two solar ISS transits!

By Phil Plait | May 26, 2010 7:23 am

I have two more amazing images for you! Both show the same thing — the International Space Station crossing the Sun — but in different ways.

The first is, once again, from Thierry Legault:


Wow! You can clearly see the station (with Atlantis docked on the left!) as it crosses the Sun. Here’s a slight closeup:


There’s a nice sunspot pair there in the upper right; the one on the right looks like a face, actually. Cute. This shot was taken at 1/8000th of a second, which froze the action nicely. He has higher resolution pictures on his webpage for this event.

The second picture is slightly different:


It was taken by Heiko Mehring and obviously shows a series of silhouettes as the ISS and Atlantis crossed the Sun. You can clearly see the same sunspots, but the path of the spacecraft is slightly different, and the spots look a bit different as well. The equipment Heiko used was less fancy than what Thierry has, but you can still see a lot of detail in the image. It really is amazing that we can see such detail on the station from the ground!

I suspect the atmosphere was steadier at Thierry’s observing site too; in the images on his page you can see the granulation on the surface of the Sun. Those granules are vast columns of hot gas rising to the Sun’s surface, cooling off, then sinking again. It’s a grand version of the convection that happens when you boil water in your teapot!

[Update: A third site with a great shot of the transit was pointed out in the comments below. I wonder how many more are out there?]

These kinds of shots take a lot of planning, a lot of experience, and a bit of good fortune (or whatever politically correct term skeptics are supposed to use these days). When I was younger I shot a LOT of film of the Moon, and got maybe a 10% success rate if I was doing well. Digital cameras and the Internet make it a whole lot easier to get spectacular shots like these. I’m glad to see more people tackling these difficult shots, and expect that we’ll be seeing lots more like these as time goes on.

Tip o’ the dew cap to Thierry Legault and Jan Sorg for sending these to me.

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (30)

  1. Wow.

    Those pictures are amazing. The Legault pic is freakishly clear! Incredibly impressive. My mind boggles to think of someone taking those from the ground.

    Makes me want to buy some nice binoculars and spend enough time with them to prove that a telescope wouldn’t be a complete waste of money. :p

  2. Cool. Again.

    So, it only takes 1/2 a second for the ISS+Shuttle to cross the width of the Sun. How wide is the path of the “shadow”?

  3. Cz-David

    This is awesome…

  4. I suppose the mathematically inclined could use the two sets of photos and produce all sorts of nifty information regarding the orbital height of the ISS, the distance to the sun, the quantity of awesomeness these guys eat for breakfast, etc.

  5. ClemsonAstronomer

    I cannot articulate how awesome these images are. Thanks so much for posting them. I’m going to try and show them in our planetarium. The kids will be in awe.

  6. Michel

    I look almost every day to pick one up, but nothing.
    Super great pictures. Both of them!

  7. Mount

    “Fortune” and “luck” are both fine, you don’t have to walk on eggshells here.

  8. The Al Dente One’s noodly appendage was resting on the shutter. It’s the only way these magnificent basterdz could get such great shots.

  9. Adam English

    It’s so weird seeing the sun like that, it puts it into perspective that we live so close to something so cool.

  10. #9. I really agree. The sun is awesome and the fact we can fly an object like a satellite in orbit and then take a picture like this is also amazing.

    Great pictures Phil!

  11. Here is another solar transit from Athens, Greece taken through thin clouds: and which made fine resolution all but impossible.

  12. I like Heiko’s website name. “Heiko looks into Space”!

  13. Jon Hanford

    With all the new technology being used to obtain these shots, how soon can we expect to see transits of satellites across *planets*? The ISS would probably cover most or all of Jupiter, Venus or Saturn (I’m estimating based on the approx diameter of the sun ~30 arcminutes vs Jupiter & Venus[max] at ~1 arcminute). Mobility and highly accurate tracking software are a few of the prerequisites. Has this already been achieved?

  14. Oh noes! Teh ISS is too close to the suns! AIEEEE!!!

  15. Glen from Australia

    Hey Phil! I finally got a solar filter for my crappy backyard scope and saw my first sun spot(s) – the ones in these pictures! So freakin’ cool. Now I can show everybody @ home what I saw PLUS the ISS and docked Orbiter! Thanx Heaps.

  16. Here are some similar images I got from my backyard scope. Not sure what that spot is, though.


  17. MadScientist

    Ah, if only I were still at a solar observatory with the latest E2V CCD detectors and a H-alpha filter. That would give me some incentive to figure out the ISS transit times and take some images.

    @Jon #14: Thierry tracks the sun by hand – an even older technology than clockwork equatorial drives. The only new(ish) technology he has is his camera – and of course the software for calculating orbits and predicting transits. As for transits by the ISS of the other planets, the question is do they occur at all? Since the ISS is so close to the earth, your location on the planet does matter. Otherwise observing the transit is no challenge at all; you will easily record the transit with a photometer. Getting enough light to make a short enough exposure will be a challenge though; you may need one of the larger terrestrial telescopes if you want the ISS to be anywhere near as well defined as in these images from Thierry.

  18. Santone

    One part of the magic is so-called “lucky imaging”, which is when the atmospheric fluctuations in front of the camera aperture statistically happen to flatten out so the diffraction limited resolution of the camera can be realized. The brighter the object, the more images per second can be taken, and so the chances of getting a diffraction-limited image increase. And the sun is pretty bright.

  19. Heiko´s friend

    The really cool thing about Heiko´s shot was the equipment used:
    A used $200 8″Dobsonian and a budget cam attached to the eyepiece with a clamp…
    The only gizmo involved was the radio controlled alarm clock he took outside from his bed room to have the exact time 😉
    At transit time he just started taking a video wich resulted in the shot published.
    Fire away Glen from Australia – it´s THAT simple…
    @MadScientist: The transit times are on Calsky:

  20. The docked space shuttle looks like the rooster on top of an old farmhouse Wind Vane.

  21. Sridhar

    Question: Why is there holes in the solar panels? Why are we able to see through the panels?

  22. Rick W.

    I have a three monitor setup at work. I’ve cropped the top and bottom of Thierry’s full image and it is now my background image. Talk about awesome. That’s about 42 inches of awesome.

  23. Seoane

    Hi! I don’t know if you have this one:

    Thilo Kranz, a staff member at DLR, the German Space Agency, took this image of the transit of the International Space Station ISS with Space Shuttle Atlantis during the STS-132 mission.

  24. Pi-needles

    @24. Sridhar Says:

    Question: Why is there holes in the solar panels? Why are we able to see through the panels?

    Lots of micro-meteorite hits since its been up there? 😉

    No, not really, I think the real answer is that we can’t see through the panels themselves and that the impression we can is an illusion based on the way the panels are layed out.

    There are gaps between panels and lot of panels so I think that answers it for real.

    Also I’m sure the ISS has a webpage or two dedicated to it (incl. Wikipedia natch) where you could a) look a bit more closely at the areas you suspect to be holed & b) ask someone with more knowledge about this than I have. Hope that helps.

  25. Messier Tidy Upper

    As I belatedly noted on the last ISS-Sun transist Legault’s photo thread (comment # 67), Thierry Legault’s Sun with ISS & Atlantis orbiter image appeared full colour with a reasonable write-up in my state (South Australia) print newspaper – The Advertiser – page 17, Sat. May 22nd 2010.

    It now adorns my pinboard. Old fashioned media & method of display true but still an amazing photo which brightens my day every time I look at it. :-)

    Magnificent photos and well done to all the folks that have taken them & had the kindness to share them with us. :-)

  26. Messier Tidy Upper

    @ 24. Sridhar – Check out this image :

    Which will hopefully help explain the “holes” in the ISS solar panels. :-)


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