See the ISS over the next week

By Phil Plait | July 1, 2009 12:15 pm

Orbits can be a bit complicated. As the International Space Station orbits the Earth every 90 minutes or so, the Earth is spinning underneath it… and not only that, the orbit of the ISS is tilted by about 50 degrees to the Equator. All of this means that any one spot on Earth doesn’t see the ISS every 90 minutes, and in fact it can be days or weeks between favorable overhead passes.

To help you figure all this out, NASA has created a nifty applet to help you determine when the ISS (and a handful of other satellites, including Hubble) are visible at your location. You can enter your country or zip code and it will tell you when the next visible pass of the ISS occurs. You may have to click "Next Sighting" a few times to get one that’s at a decent time, but keep at it.

ISS and the Shuttle rising over the trees.
I shot this picture in 2007.

As it happens, the next week or so yields many favorable overhead passages of the ISS in the US — think of it as a holiday celebration (even though there’s that pesky I in ISS). For me, in Boulder, the next good sighting is on Monday July 6, when it passes very close to directly overhead at 10:17 p.m. (there are a few sooner but they are early in the morning when I tend to be asleep).

This application also provides you with a map of the sky to help you out.

And while it’s nice and all, I still prefer to use Heavens Above, a fantastic resource on the web for satellite passes, sky mapping, and tons more. All you need to do is put in your latitude and longitude as accurately as you can (Google Maps will help there) and it will give you a table of dozens of visible satellite passes, including ISS, Hubble, and a gazillion more.

For you Americans out there, the Fourth of July is a great time for skygazing; even though the Sun doesn’t set until late, a lot of folks will be out after dark anyway. So why not stay outside a few extra minutes and watch the real fireworks?


Comments (37)

  1. «bønez_brigade»

    “…I still prefer to use Heavens Above…”
    I’ll second that. H.A. always has quite a large selection of objects/events to watch, with helpful sky maps and info on the various points of light (and rather accurate prediction times, at that).
    [Oh, and thanks for the heads-up about the upcoming ISS passes.]

  2. Almurray1958

    upcoming Massachusetts visable are all between 01:30 and 04:30 until Jul 5, there is a partial (shadow) pass at 23:58. That is if it ever stop raining here. Been using Heavens above for more than 10 years, excellent site.

  3. Twitter users can also follow @twisst or use to get personalized updates on when the ISS is viewable from their location.

  4. @Almurray1958

    That is if it ever stop raining here.

    No kidding. I guess we’re in monsoon season.

  5. Bigfoot

    Heavens Above is definitely heads above any other resource for this, but kudos to NASA for also sharing this info.

    One of the things worth mentioning is that you don’t just need a pass above you in a dark sky, but a pass above you when your sky is dark AND the ISS (or other night object) still has a view of the Sun from its orbit above — which can;t be too long before Sunrise or too long after before sunset.

    Its definitely cool to see the ISS (especially just before after shuttle rendesvous, when both can be clearly seen). I always look at the detail info so when it disappears into Earth’s shadow, you know how far it travelled in just that minute of time (something Heavens Above tells you if you click on the details).

    To truly inspire awe in the minds of youngins around you, if you plan on catching and pre-announce a -8 magnitude Iridium flare, and gather the kids using an accurate-to-the-second watch and make them look up at the right moment, they will witness the flare which quickly appears, rapidly grows bright, becomes absolutely brilliant for a couple of seconds, and fades rapidly away, all within the just a handful of seconds. At their peak, these things actually produce glare in your dark adjusted eyeballs! Another great Heavens Above feature — definitely check these out!

  6. Charles Boyer

    Another good resource is Simple Satellite Track from spaceweather. Just type your zip code into the entry box here and see a list of all the flybys in your area over the next ten odd days:


    I was pleased to learn that we will get a visible pre-dawn and a visible post-sunset flyby on July 7, 8 and 9 here in NC.

  7. chili

    To echo Bigfoot, nice on NASA for adding this resource. But I’ve been using Heavens Above for years and will continue to do so since it provides a lot of good info in a single location. Not just satellites, but also sky charts, comet locations, etc. Simple Satellite Tracker lives up to its name: simple, no fuss and not many objects available.

    By the way: Happy Birthday Canada!

  8. Thanks, Phil. I use the ISS NASA applet every time I go out to star gaze. If you have an iPhone or iPod Touch, I highly recommond “Starmap Pro.” It’s the coolest app I have now. It doesn’t do sat tracking but has all the star, planets, nebula and such. Here is a more detailed review:

  9. Kevin

    We always try to show off ISS passes, along with Iridium’s during our public observing sessions at our observatory. Just a few weeks ago we had a -8 flare during twilight, and made sure the public got to see it.

    ISS over Observatory

    And just under an hour later…

    -8 Iridium Flare

    Last Winter I caught the ISS as it went through Orion

  10. tarrkid

    About a year ago, in a bit of nerdy excess, I actually wrote a PHP script to periodically scrape the HA data for my location and export out an iCal feed that I can import into Google Calendar. Now I’m never without my satellite passes!

    Sync that puppy to my iPod Touch thanks to NuevaSync, and I’ll be sitting around the house when my iPod will beep at me to tell me that there’s a pass coming in 10 minutes. Just-In-Time Astronomy!

  11. I was also going to mention the twitter account, but it looks like bsander beat me to it.

  12. Robin

    Got anything on telescopes? That is the next lesson in my class. We just finished discussing the “Face” on Mars, volcanic sunsets, AND using Heavens Above for an assignment. HA is very cool.

  13. Flying sardines

    For you Americans out there, the Fourth of July is a great time for skygazing; even though the Sun doesn’t set until late, a lot of folks will be out after dark anyway. So why not stay outside a few extra minutes and watch the real fireworks?

    Now then, what if the ISS astronauts were to launch say a couple of flares or fireworks from the International Space Station* into space esp. during a fly by over the US (or France -Bastille Day too innit?) on the 4th July? 😉

    How might that look? 8)

    * I’ve said it before & I’ll say it again – I sure wish they’d give the station as a whole a proper name argher than just its separate modules. ‘Freedom’ / ‘Babylon-1’ / ‘Serenity’ / ‘Harmony’ / ‘Skylab II’ /’DeepSpace -1′ / ‘Cooperation’ / Orbiton / ‘Kennedy’ / O’Neill’ / ‘Von Braun’ / whatever … anything beats that dull clunky acronymn its currently lumbered with.

    In My Humble Opinion Naturally.

  14. Ken

    OK, for an astronomy nOOb … what is the “magnitude” scale, and how do you relate to it? Am I understanding right that the farther negative is brighter? What can one expect to be able to see naked-eye in a reasonably light-polluted town (not city – on a really good evening I can *just* barely make out a faint smudge of Milky Way. I’m not sure I’ve seen Polaris yet).


  15. «bønez_brigade»

    @Flying sardines,
    “Freedom” was indeed one of ISS’ original names. Much like the previously discussed MSL, ISS works just fine for me, though.

    BTW, I came across an old (c. 1992) info packet for SSF at a flea market a couple of years ago (and snatched it up for $1, I think). They projected a “man-tended phase” by Spring 1997 and permanent inhabitance by early 2000 — so, they weren’t too far off on that. However, they also projected quite a bit of scientific research to be carried out… and with research being conducted by (in addition to NASA & gov’t peepz) people from schools, universities and private companies… throughout its “30-year life in orbit”…


    Correct. Lower numbers mean brighter appearance. Might as well start here for a lengthier explanation.

    If you can see the Milky Way where you are, then objects from ~ mag. 3.5 to 4 should be possible for you (depending on yer vision, of course). Polaris is ~ mag. 2, so you’ll be able to see it. An easy way to find it is by using the “Big Dipper”, like so:


    [and, methinks this comment will get sent to overnight moderation purgatory… yep]

    BTW, Phil, any chance of making the orange/brown color for hyperlinks stand out a bit more?
    [or did I miss a previous discussion/war over that?]

  16. Mike Wagner

    I’m on Prince Edward Island for the summer and it’s the first time in 20 years I’ve been able to see the Milky Way *at all* at night. I forgot how truly breathtaking the night sky is here.

    At 11pm I can usually go out and catch 3 satellites passing by within 5 minutes, but have only noticed one shooting star so far.

    I’d looked for a decent planetarium program, and Stellarium is nice, but I don’t know if it has an earthbound view of the skies. I just end up jumping around looking at planets :)

    Heavens Above is awesome! I’d not seen this site before, but I poked in my coords and the ISS is going right over top of me in the next half hour.

    And it’s full cloud cover here. ARGH!

    I brought my mom outside to look at satellites and a bright star that pulses red, white, blue, and even though she’s lived here for years she hadn’t actually stopped to look at the sky at night. After that evening she’s planning on getting a telescope next summer :)

    I’ve already forwarded the Heavens Above link to her.

    Thanks :)

  17. fred edison

    You can also use the HA database selection. Select your country and then type in the name of your town/city. I think it keeps your personal coordinates in HA cookie(s), but if you’re like me you clean out your cookies every so often and have to redo it.

    I’m with you, Phil. It’s my favorite kind of fireworks. I *love* to watch the ISS fly over and make a point to catch it when possible. It’s quite a sight, especially when it flies directly overhead and shines like a white jewel in the sky. Then I think to myself, there’s astronauts/humans onboard the ISS, cruising along at a brisk 17,500 MPH or so. Catch it if you can.

    Here’s a NASA flash animation of International Space Station assembly from 1998 through 2010. The ISS is better than 80% complete. Space Shuttle mission STS-127 to launch July 11 (fingers and toes crossed) will notch up that percentage with scheduled work on the ISS. Along with that beautiful jewel getting a little bit brighter in the sky.

    Click on the “Full ISS Assembly….” button to see it.

  18. @Neil,
    Go take your crocoduck for a walk.

  19. @Bigfoot: On Heavens-above you can know when the ISS is in shadow or not without going into the details as the starting altitude will be 10 degrees for no shadow, higher for shadow entrances / exits. The site won’t show passes in shadow.

    @Flying sardines: How about “Colbert”?

  20. Andrew

    Just watched the ISS pass overhead from western Canada. What made it a bit more interesting was that it was being followed by what I assume was Progress 33, some 50 or 60 degrees behind it and considerably fainter. According to Wikipedia, Progress undocked on June 30 and will rendezvous with the ISS again on July 12th, so it might be keeping loose formation with the ISS for a while. If so, something to watch for.

  21. BigBob

    Fred Edison @17
    No worries about cookies, just select your observatory site from the Heavens-above database then when it has your location and takes you back to the homepage, simply save the page as a favourite. I have two Heavens-above favourites, one for Olton in the UK where I live and one for Iridium flares at my workplace, (because a few miles makes a big difference with Iridium flares). Set them up once and get instant predictions whenever.

  22. Alan

    I got my one public nerd certificate by being published in New Scientist informing them about Heavens Above – it’s a great site, but it would be good if it had some sort of interface to a scheduling system for alarms on my phone – I haven’t seen an iridium flare for years because I always forget at the time …

  23. tarrkid

    OK, so, this is AMAZING…

    Next week I have THREE viewing opportunities where I live where the magnitude is brighter than -3.0!

    -3.5 on Monday, -3.4 on Wednesday, and -3.3 on Friday.

    I’ll (once again) be taking my kids out there, watching it fly by, and telling them – HUMANS PUT THAT UP THERE. HUMANS ARE ON THAT RIGHT NOW.

    Is it due to get any bigger? Magnitude -3.5 has got to be pretty close to being visible in the daytime.

  24. Neil

    Let’s see.
    An ISS orbit is 90 minutes.
    And so there’s a sunrise or sunset every 45 minutes.
    So there’s about 16 orbits per day.
    So there’s about 32 sunrises and sunsets viewable per day from ISS.
    And they’ve allegedly been up there for every minute of every hour of every day of every year for nearly ten years.
    And so, roughly, that’s been about 116,800 sunrises and sunsets
    And still no video of a sunset or sunrise.
    Not a single one.

    But why should they?
    They’re busy with really important experiments to do.
    And besides the only people that would want to see that are people that will never get to the ISS and so who cares?
    Why care about providing a smidgen of entertainment value to the prole taxpayers that paid for the thing?
    The astronauts do not and should not and will not, ever, ever, ever take their attention away from more important things to photograph the ISS on the dark side of Earth in silhouette against a brilliant star-filled universe.
    It would be beneath any astronauts dignity to press record on a videorecorder pointed out an ISS window and trouble themselves to return 90 minutes later to download the video to YouTube.
    ISS is a hoax.
    What you see in the sky is a lighted prop.

  25. Davros

    last night the timing was just right for me to see The ISS just after i got off the train there is a good side to getting home after dark
    and another chance tonight a bit later

    @ Neil a picture of a sunrise would be proof but all the Other data and pictures are not good enough fool

    ps my location is a bit North of Gosford NSW Australia

    sorry for feeding the troll

    Ps my Location is East Coast of Australia aprox 80 KM north of Sydney

  26. Neil

    What you saw was an ISS prop.

    A picture of a sunrise would not be proof and neither is the mediocre video and photos thusfar supplied during ISS’s alleged 10 years of operation.

    Proof would be a public demonstration of the operation of NASA space suit in a high vacuum chamber before a sworn under oath team of technically qualified American witnesses.

  27. Mike Wagner

    Well Neil,
    While you’re insulting NASA and America’s astronauts, you’re also insulting 15 other countries including Canada.
    On behalf of Canada I would like to present you with a bottle of fine mineral oil. It may assist you in removing your head from your ass.

  28. Davros

    @ Neil
    See the Mythbusters Moon Special for that

    or Google space walk pictures

    or pictures of sunrise from ISS

    I could not Preview the Clip as i am at work but i think it is the one i remember
    of sunrise and the ISS from the Shutle

    Sorry feeding the Troll again

  29. «bønez_brigade»

    Is this “ISS prop” also located ~220 miles overhead and traveling in excess of 17,500 mi/hr (possibly within the ether)? Or, is it instead maybe something that appears in the particular sheepl…, err, I mean viewer’s eyes — such as an aftereffect produced by all those silently noxious chemtrails (which are clearly courtesy of the NWO)?

    Unless, of course, you’re a Poe, no?

  30. Neil

    It’s not what those photos and video show but rather what they don’t that lead to me to believe they’re fakes.

    For 32 times a day, there’s an opportunity to videorecord either passage of an ISS in silhoette against a brilliant star-filled sky slowly illuminated by the rising sun and the fantastic blue of the Earth or the reverse. But no. They give us that boring thing you provided the link for. Not a star in sight. Never a star in sight. For fifty years never a star in sight. Something’s very wrong.

  31. Bishop

    My wife and I just finished seeing the I.S.S. fly over Sacramento, Ca. As it was about 3/4 across the sky, we notice a small “light” following about 15 degrees behind the I.S.S. It was not a plane. It was not blinking. Not even a few seconds later, I looked towards the East and seen one more of these slow moving objects. I remember when I was a kid, we used to call these things “satellites”, but I not so sure lately (I’ve been listening to Coast to Coast AM nightly).

    This was cool. Not only did we see the I.S.S., but we seen two “ufos”. For a comparison, there was a few high flying planes over head, but those had red lights and a blinking lights. These two ufo or satellite objects was a solid white color and moved slowly across the sky and then faded.

  32. Dave Wilde

    At the top of his Blog, you mention the “pesky I in ISS”
    Have you seen a map of the Globe recently. The US of A is not the only land mass.
    Have you seen population Figures lately India = Billions China = Billions, usa = 0.3 Billion
    Have you read the papers lately, the upcomming economies will be the BRIC ecconomies ( look it up – it will educate you ).
    Have you seen the financial figures lately, Europe has pumped more money into ISS than usa.
    – OK I’ll give you that “you” put it up there, but everyone else is keeping it up there.
    Don’t be so Parocial ( look that up also ).


  33. Dave Wilde (#35): I suggest you look up something as well: the definition of the word “joke” (or “humor” if you prefer). Also, I looked up “parocial” but didn’t find it, so I further suggest you look up Skitt’s Law.

  34. Surya Prakash C N

    please provide me as to how and when i can view ISS through 4″ telescope.
    i am very much eager to get information on this. further it is requested to please provide me through e-mail abiut the ISS over india occurs as and whenever.

    thanking you,
    yours faithfully,

    surya prakash c n


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