Heavens Above! This things not working?

[JamesK]

Please excuse the cheap pun.

I logged on to heavens above a couple of days ago, to enter my location- I found my area (which is fairly small) in the database, presuming it to be 'accurate enough'. I found times for satellite passes and Iridium flares. When I went out that night, I took the data with me. By the stars I could easily see easily to magnitude 4, dimmer with some effort through naked eye. I found one of the sat prection to be correct, and I happily followed it over the sky with my binos.

However, another two sattelites I should have been able to see I could not find. I accept this is probably down to skill as it was my first attempt at observing sattelites. When I got to the Iridium flares, I made sure I was looking in the right direction at the right time. And nothing happend. Are these just as they say, predictions? I thought being accurate to the second they would have apperaed give or take miniute at the published time? Surely I could not have missed something at magnitude -5!?

Is this something I am doing wrong - or are these predictions not always reliable? How can I improve my chance of seeing sattelites, or a flare.

Thanks in advance,

James.

[lunator]

Hi James

I have always found HA to be accurate.

For the really bright flares I don't use any thing but my eyes to observe.

Cheers

Ian

[Talitha]

James, I recall a few times when I'd written info down and then decided to go back and print the page only to find that the time was different. No idea why it did that.. maybe the site receives updated info and automatically changes it? Try checking the page just before you go out, maybe that would help.

[JamesK]

Thanks.

Will try and check closer to the time.

To be honest, I think I'm going to put this one down to skill. I've never really used co-ordinate systems before, just used TLAO and nearby guideposts to find things. I'm doing this really because I want to build up a decent knowledge of the sky before further investment!

Perhaps I should plot on a star chart before going out, I think I prefer star-hopping and guideposts for finding things rather than co-ordinates. Though I'll probably have to learn them well eventually.

Thanks, James.

[ashenlight]

Hi James,

Apologies if you have already thought of this. I can't remember from the last time I used HA, but do the times take into account British Summer Time? You might need to add an hour onto the predicted times they give you, if this is the case. However, as some of the other predictions were correct... maybe the fault lies somewhere else. As Ian said, iridium flares are so bright, you just have to be looking in the general direction to be able to see them - I've only seen one but I sure couldn't have missed it.

Hope you manage to work out what the problem, using HA is one of my favourite astronomy-related things to go, it's so satisfying when you can point something out to someone and say 'that's the ISS/ so and so satellite.'

Best wishes

Amanda

[The Warthog]

It's kinda neat when you can direct your friends gaze upwards to an Iridium flare, and then tell them what it is, and how far away it is. I've got about 50 Iridium satellites on my list including #33, which crashed into a Russian satelllite a while ago.

There are many ways to miss them. You can miss one while you are checking your watch. The times are quite accurate, so set your watch using a reliable time service. I use the National Research Council (Canada) time from CBC Radio. I sometimes get confused between east and west, and have missed some flares because I was looking in the wrong direction. All you need is to be facing the right direction and looking up in the sky at about the right angle.

They are quite fun to see, and if your skies are clear, you can see the satellite that produced the flare before and after it flares. they have a magnitude of about 6. I have seen -5 and brighter flares through thin cloud.

[Talitha]

WH, thanks for reminding me.. forgot to say that I always synchronize my watch with the site's 'what time is it' link near the bottom of the main page.

[doat1]

I am new to all of this, could someone explain what Heavens Above is? It seems like a site or program that you put your location in and it tells you when you can see planets or things of that nature correct?

[DanDare]

I am new to all of this, could someone explain what Heavens Above is? It seems like a site or program that you put your location in and it tells you when you can see planets or things of that nature correct?

Among other things its a site that will, after you have entered your location, predict the times that the ISS , satellites and Iridium flares can be seen from a your location. Here's a link. Heavens-Above Home Page

Its a great site and well worth checking out.

Roy

[jgs001]

I believe there is a check box for updating the predictions if you adjust for summer time. I keep a watch in sync with the HA clock for catching images of satellites. The flare predictions have always been on time, but as you only have about a 30 second window, you do need to be looking at approx the correct location in the sky. I have seen the ISS passes to be up to 3 minutes behind the prediction. I believe that HA gets the TLE (not sure what that means) positioning data from spacetrack and updates based on that. If you run orbitron on your PC then you can get the latest TLE updates just before making your own predictions, they will match with HA, but HA appears to only show current active satellites, and not test and backup units, so orbitron actually shows more.

[doat1]

Among other things its a site that will, after you have entered your location, predict the times that the ISS , satellites and Iridium flares can be seen from a your location. Here's a link. Heavens-Above Home Page

Its a great site and well worth checking out.

Roy

i thought it was something like that, thanks for the link much appreciated.

[Capricorn]

Found HA a little odd in its action.

I was entering position data at work and getting a different result from when I entered the same data at home.

It was for the ISS, but left me wondering why the difference in the predicted elevation of the ISS for what the same input information.

I would always double check the times as we are presently on BST and what HA defaults to I cannot recall.

[tinvek]

HA gives its results in local time, if you click the link at the bottom you can see what it thinks is the local time for your location and also a UTC figure. if the local figure agrees with your watch then your ok, if its an hour out, just make the adjustment to the times or if you have a spare watch or spare timezone on your watch / phone set it to the sites "local time"

[The Warthog]

I have always gotten the correct local time from H-A without any fuss. I set my watch by the National Research Council signal as I am sure it is more accurate than a time that comes over the internet. H-A is a German site, so I am sure it is very, very precise.

[Capricorn]

I never had a problem with the time. I checked for the ISS for a given date and found that it said the ISS would go over at whatever time at an elevation of 82deg, just about right overhead. Checked the next day at work, another person I work with has an interest, and yep the ISS was to go over at the same time but the elevation was now something like 38deg. Somewhat lower.

I was a bit puzzled and rechecked at home that evening, it said 82deg, next day at work it was 38deg.

Coordinates given were 52N 0W, just north of London.

Never did see it as it was cloudy. But never did determine why the different elevations.

[Talitha]

James, I found out something regarding the Iridium Flares which may be of help. Apparently the chart provided on H-A is to be used as an overhead one. If you use it like a terrestrial map, you'll be looking in the wrong direction: link

[JamesK]

Thanks Talitha, knew it would be somthing like that! I didn't print the map, just the direction and alltitude so that will be the problem.