funny to see this today - I just used it yesterday for the first time, and saw the ISS fly by above Seattle, with the naked eye. Was so cool!
coolest part was, I saw it pass by sometime around 8:00pm. Made dinner. Ate. Did the dishes. Now it's around 10pm. Checked the app again, and... the ISS was passing by again in ~5mins. Looked out the window, and... there it is!
I had this moment of total awe - over the course of my dinner and some cleanup, that little craft, with humans in it, traveled around the entire planet, and there it is again!!
hoping to see a starlink train next, weather permitting.
My favorite part of this experience was seeing it “turn” above my head. I was finally able to truly visualize from a first person POV, the sign wave I had previous seen on Mercator orbital projections... as seen on the wall of the classic NASA control room view.
It honestly felt like I was able to visualize a whole new dimension.
I trust that you thought you saw that, but bear in mind that satellite do NOT turn at all.
The turns you see on Mercator projections are just that: projection artifacts. Circular low earth orbits (like the ISS) are great circles on the sphere. (The equator line is a great circle for example, but there an infinity of them, with various inclinations)
The turn that you think you saw in real life is just a combination of perspective, optical illusion due to landscape or objects in your field of view, and your mental model of orbits making turns (which they don’t).
Usually, if you can see the ISS flyby, you'll get to see it a couple of times. I was out at a dark sky spot one night to see 3 passes. Caught one in a timelapse sequence I was shooting at the time.
I use an iOS called "ISS Finder" that sends you notification right before a ISS flyover. It points you to the right corner of the sky and gives you a short bio of the astronauts on board.
While typically such actions would annoy me, I would say it seems pretty reasonable in this case.
It seems like it's just doing it's just gracefully degrading from the precise location to imprecise. I do think I tracking free option would be good though.
The magnitudes are actually logged to the dev tools console. But be aware that the magnitudes calculated by all tools like this are little more than educated guesses, and the real brightness can easily be different by several magnitudes in either direction.
This might be a dumb question, but how far out are really accurate predictions of satellite locations good for without measurement? Like, if I kept scrolling forwards in time, how long would it take before the prediction of the satellite's location was off by an arcsecond (I'm guessing days)? Or a full degree (I'm guessing many years)?
It depends on a ton of factors. In general there's more uncertainty for lower satellites, especially ones that straddle the thermopause. The error isn't necessarily constant, it depends on hard to predict events like space weather.
For something in LEO, an arcsecond of error is only a few meters. If you're plugging data into a standard orbital model like SDP4, a few meters is within the typical error margin basically as soon as the TLEs are published.
A full degree of error would take a while. For what it's worth, NORAD publishes new TLEs for things in LEO pretty regularly, sometimes multiple times a day. For higher up objects it can be more than a week before the refresh the data.
I'm not sure what the answer is, but something to keep in mind is that most are reboosted every once in a while. Once this happens, it should be completely off.
These days, even with Los Angeles light pollution nearby, I can just look up at sunset and spot multiple satellites per minute. I remember how exciting it was to see a satellite when I was a kid. Now it is pretty commonplace, and only becoming more so.
This made clear for me just how big the starlink constellation is.
I can see the ISS or some random satelite every odd day, but I can look up and see a whole trail of starlink satellites passing over basically any time...
As much as I love this type of app, I can't help but feel depressed that before we know it there will be an app that does the opposite.
We are allowing governments and billionaires to pollute our view of the cosmos.
The night sky is such an important part of the human experience and most people never experience it in all its beauty.
Allowing American business owners and world militaries to block it from above just makes my stomach turn if I am honest.
this reply is nothing but hyperbole and fear mongering - I've been out in a very rural dark sky location and seen a group of starlink satellites going past. they did not obscur or brighten the view of any stars. If you really want to be concerned about something, worry about light pollution in urban areas, or people polluting the atmosphere. I'm sure the folks living in the grey smog of haze in Lahore or Mexico City would be more concerned about breathing clean air, and having clean air to use a telescope if they wanted to, than occasionally seeing a satellite flying past.
I disagree that this is hyperbolic -- to be in the wilderness is to be alone and away from humanity. A starlink train is a stark expression that one can never really be alone anymore.
When I was a kid, it was a fun/rare occurrence to see the occasional satellite -- they were more common than the night's meteors, but not by more than a factor of ten or so. Today, there are oodles.
in my mind, a starlink train is a "oh, neat, look at that", same as seeing a collection of meteors, it's not like a diesel-electric locomotive suddenly appears in your wilderness...
On the bright side (pun intended), the easier it is to put things in space, the closer we'll be to being able to - whenever we fancy - get to an altitude where those satellites are below us, so to speak :)
So I feel like this is a self-correcting problem, in a sense. We need more astronomy capability in-orbit (and beyond!), and it'd sure be nice if we as humans could chill out up there and do it ourselves, with our own eyes, unhindered by any planetary atmosphere. The proliferation of LEO satellites only serves as further motivation toward that goal.
Sometimes! Conditions have to be just right. Specifically, only the most recently launched few can usually be seen as they travel to their final orbits over several weeks; the thousand plus operational ones generally can't be seen (which is good as there will be tens of thousands soon). And of course also they can only be seen if they happen to pass over in a time window about an hour after sunset or before sunrise, not the rest of the night. And these days SpaceX is deliberately rotating the satellites to reflect less light toward Earth, so sometimes they are still difficult to find.
Any satellite can flare and if you look at a dark sky you'll see something go over before long. But the Iridiums were special because they were so predictable and bright. I really enjoyed pointing them out to regular people who had no idea about satellites. The ISS is the only thing now, but it's not as bright as a good Iridium flare and it stays in the sky so long that it's more like a plane flying over than a flare.
coolest part was, I saw it pass by sometime around 8:00pm. Made dinner. Ate. Did the dishes. Now it's around 10pm. Checked the app again, and... the ISS was passing by again in ~5mins. Looked out the window, and... there it is!
I had this moment of total awe - over the course of my dinner and some cleanup, that little craft, with humans in it, traveled around the entire planet, and there it is again!!
hoping to see a starlink train next, weather permitting.