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After a little more research, I'm finally satisfied!
I was confused that two Iridium satellites were so close together. It turns out that the satellite that produced the bright flare (Iridium 90) is a spare. It's in a storage orbit, is not in operation, but is there to take over if another Iridium satellite fails.
The second Iridium satellite (no. 12) is operational. Mystery solved!
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We tried but couldn't spot it. But, all was not lost....we saw a beautiful shooting star between the clouds!!
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Thanks for identifying the mystery satellite, Tom. I wonder if the storage orbit is in the same plane as the operational orbit, just a bit further out. My understanding is that it takes much less energy to change orbital altitude than it does to change orbital planes.
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Exactly right, Jeremy. Just changing the height of an orbit requires a lot less energy and fuel than changing direction (if you're interested, the latter is called an inclination change). In addition, an inclination change often involves having to change the height of the orbit to slow the satellite down a little before the next maneuver, before changing the height back again.
As for the two Iridium satellites we saw last night, the spare is actually in a slightly lower orbit than the operational one.
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I'm going to be away for a few weeks (taking Pam to the home country and Ireland) so here are some passes while I'm not here:
23rd May: Very bright ISS pass. Hopefully, HOTPE can provide details nearer the time.
Sky track:
https://goo.gl/dLfOvI
24th May: Very bright Iridium flare at 19:47:29. This should be easy to spot. It's going to happen almost exactly halfway between Jupiter and Arcturus (see my post above about locating both objects).
Sky track:
https://goo.gl/QqJ0yC
31st May: Very bright Iridium flare at 19:14:04. It will occur a few degrees above Jupiter.
Sky track:
https://goo.gl/4mISz8
Have fun!
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Have a good trip Tom and Pam!
Thanks for the schedule of coming attractions. I'll do my best to hold down the fort here on the satellite thread while you're away.
It... lends weight to Goethe's felicitous description of architecture as 'frozen music.' ... Does this, I often wonder, make music 'defrosted architecture?' Listening to Bach's Goldberg variations as I often do on walks when motorway noise and other auditory intrusions preclude the music of silence, it strikes me that it might. - Pub Walks in Underhill Country, Nat Segnit
"I'm at that stage in life where I stay out of discussions. Even if you say 1+1=5, you're right - have fun." - Keanu Reeves
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HOTPE, thanks for starting this thread [
] It's more interactive for the backyard astronomer, star gazer (that'd be me) and the astronomer (that'd be Tom) guiding all the above and we are all enjoying what's happening out there in the night sky! I
used to do a lot of star gazing and this thread and the contributions people have made in information has gotten me out there again star gazing. Mahalo!
TomK, I appreciate your giving these kinds of heads up on the scheduling of iridium flares and explaining how to recognize and understand what we're observing. That was kind of you to give us the scheduling of future viewings for the ISS and iridium flares.
Last night, my husband and I saw 3 satellites. The 3rd was just a bit south in it's path but traveled the same direction. The 1st iridium flare was fantastic! Truly amazing!
Safe travels TomK to you and Pam. Going to the motherland, eh? I've recently discovered I have a lot of ancestors going back centuries from those areas up to those that sailed over to the east coast in the 1500's...
Don't forget to bring this w/you...
https://goo.gl/p7xNO7
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Thank you, mermaid, but I'm not flying United. Hell will freeze over before that happens! Both Pam and I have been treated extraordinarily badly by that airline, Pam's story would have made the news if it happened today - a disabled woman forced to lift her bags with medication up into the overhead panels, which she can't reach, with the flight attendants refusing to help. Fortunately, some friendly Australian passengers intervened.
Your post was much appreciated, just wanted to let you know that. It's really nice to hear that one or two people are finding that the night sky can actually be quite interesting and not just very beautiful! I think when you have some idea of what you're actually looking at, it makes a very big difference to your appreciation of what's up there.
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One night while living on Oahu, and observing many a satellite, we saw 2 satellites traveling towards each other. When one passed the other, one of them made a hairpin turn and started following the other satellite. I called Bishop Museum Planetarium the next day inquiring whether satellites had the capability to do such maneuvers and was told no.
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They were correct. No satellite can do that, at least not currently - such a maneuver would require an enormous amount of energy. In addition, even if it were possible, such a maneuver would almost certainly destroy the satellite from the g-forces involved (17,000 mph in one direction takes some doing to get it doing the same the other way).
I suspect you might have been seeing military aircraft at very high altitude - their navigation lights is likely how you spotted them. I've seen that same thing before, but during the day and out in Arizona where the air force tends to practice a lot.
