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View Full Version : Saw the ISS fly over twice in one evening



Tucson_Tim
2009-Apr-03, 06:58 PM
I know it happens pretty often but I've never managed to see the ISS flyover twice in one evening before last night. The first flyover at 19:05 was great, 5 minutes in view. The second flyover at 20:35 was only about a minute in view but still pretty bright. I also saw a very bright Iridium flare. All in all, a good night of satellite viewing.

You can almost set your watch by the Heavens Above times of transit.

Heavens Above website: http://www.heavens-above.com/

KaiYeves
2009-Apr-03, 07:01 PM
It's been cloudy here all week, but if it's clear tomorrow for 100 Hours of Astronomy, that's one of the first things I'm going to try!

Tucson_Tim
2009-Apr-03, 07:08 PM
You can't go wrong with the Heavens Above website. All you have to do is register to create a (free) account, plug your latitude/longitude in, and your good to go . . . .

KaiYeves
2009-Apr-03, 07:15 PM
I created an account last week. But the first few days, I mistakenly read the next day's pass time or made similar mistakes, and then these clouds set in.

slang
2009-Apr-05, 11:18 PM
You can't go wrong with the Heavens Above website. All you have to do is register to create a (free) account[...]

Not to be pedantic, but you don't need to create an account. You can also just pick your location, and bookmark the URL with the location (lat=,lng=,etc) in it. Not trying to make you look bad, Tim, just making sure that this wonderful resource is not avoided by people hesitant to create (even free) accounts.

KaiYeves
2009-Apr-06, 12:44 AM
Oh, lookie- first clear night this week and Heavens Above tells me there won't be any visible passes for ten days!

Tucson_Tim
2009-Apr-06, 01:05 AM
Oh, lookie- first clear night this week and Heavens Above tells me there won't be any visible passes for ten days!

See if there are any Iridum flares for your location. While they are short-lived (only a few seconds) they can be quite amazing and very bright, sometimes magnitude -8.

Also, if you want a little more challenge, but a lot less spectacular view, the HA website has transit times for the Hubble Space Telescope (HST). It rarely gets brighter than magnitude 1.5 and can be as dim as magnitude 3.

KaiYeves
2009-Apr-06, 01:11 PM
Hubble only goes over my house at three in the morning. I am not getting up at three in the morning. Not even now that I'm on vacation.

slang
2009-Apr-06, 03:11 PM
Lucky you, it's never (AFAIK) visible here!

Sam5
2009-Apr-06, 03:34 PM
I know it happens pretty often but I've never managed to see the ISS flyover twice in one evening before last night. The first flyover at 19:05 was great, 5 minutes in view. The second flyover at 20:35 was only about a minute in view but still pretty bright. I also saw a very bright Iridium flare. All in all, a good night of satellite viewing.

It's certainly amazing, isn't it! :)

You know, the ISS really isn't very far away. About 300 miles up. That's about as far up as your state is wide.

Go to a globe and look at the width of your state, then see how far that would be off the surface of the earth. It's not very high. I'll bet if we signaled them from earth with a bright search-light, they could see it.

hhEb09'1
2009-Apr-06, 04:02 PM
You know, the ISS really isn't very far away. About 300 miles up. That's about as far up as your state is wide.Even less than that, heavens-above.com (http://www.heavens-above.com/IssHeight.aspx)has a graph of the ISS height in km for the last year, it shows heights between 336 and 360.


Go to a globe and look at the width of your state, then see how far that would be off the surface of the earth. It's not very high. I'll bet if we signaled them from earth with a bright search-light, they could see it.I wonder if they could see a green laser pointer? :)

KaiYeves
2009-Apr-06, 07:45 PM
You know, the ISS really isn't very far away. About 300 miles up. That's about as far up as your state is wide.
"In this city, the space station is closer than the nearest beach. Draw from that what you will." -Joe, our Space Academy counselor.

ngc3314
2009-Apr-10, 02:26 PM
Also, if you want a little more challenge, but a lot less spectacular view, the HA website has transit times for the Hubble Space Telescope (HST). It rarely gets brighter than magnitude 1.5 and can be as dim as magnitude 3.

In my experience, it's even a wider range than that. I've seen flares (from Tucson, BTW) to about magnitude -2, and in some passes it hasn't even been a naked-eye object from Kitt Peak. I don't know of any satellite with a wider range of brightness - the combination of seeing bright/dark sides of solar arrays, their shadowing, and the great variation in cross-section from sides to end-on must all be in play. CGRO was much more consistent (being a big minivan-sized lump of metal and all, without quite the solar-based pointing constraints of HST).

On its bright passes, HST is much the most obvious satellite with no one on board. I can pick it out by its rightness and relatively slow apparent motion even when I didn't check Heavens-Above in advance.

Tucson_Tim
2009-Apr-10, 02:34 PM
In my experience, it's even a wider range than that. I've seen flares (from Tucson, BTW) to about magnitude -2, and in some passes it hasn't even been a naked-eye object from Kitt Peak.

I'm sure you're right. I just checked a a few pages of views on the HA site and dug out the dimmest and brightest values. With its shape, solar panels, and attitude changes, I'm sure it can flare brighter and be far dimmer.

Tucson_Tim
2009-Apr-11, 12:50 AM
In my experience, . . .

I put your coords (87.5W 33.2N) into Google Earth and you have a cloud protecting your location in Alabama. :)

And the Heavens-Above website has been down all day . . . .

bunker9603
2009-Apr-11, 02:34 PM
And the Heavens-Above website has been down all day . . . .

I was wondering...

Tucson_Tim
2009-Apr-11, 02:36 PM
And the Heavens-Above website has been down all day . . . .

I was wondering...

Yeah, it's still down. Anybody have a clue?

loglo
2009-Apr-12, 05:06 AM
Easter IT upgrades are going on everywhere... but it seems to be back up now.

mahesh
2009-Apr-12, 12:24 PM
Even less than that, heavens-above.com (http://www.heavens-above.com/IssHeight.aspx)has a graph of the ISS height in km for the last year, it shows heights between 336 and 360.
I wonder if they could see a green laser pointer? :)

Nice graph, hhEb....reminds me of 'breathing' ...inhale/exhale...up/down...

currently, just now, the ISS and Hubble elevations are increasing...imagining inhalation...

edit:
oh loglo, thanks for the wake-up....

elevation?....i mean altitude