While naked-eye observing in perfectly dark skies in northern California (10 Pleiads visible!) I noticed something amazing. I spotted to slow-moving lights in the sky, obviously satellites. They were moving at the same speed, only around 10 degrees apart from each other, and in roughly parallel lines.

Has anyone seen something like this? I'd like to know.

Without knowing specifics as to when, what direction, what elevation it's impossible to say for sure.  You may have seen the International Space Station and the Space Shuttle.  That is a rather common occurrence and a very neat treat for the ground based observer.

They were moving either upwards or downwards, I can't remember which. It was quite late at night and they were in the northeast. They could've just been airplanes, I wouldn't know.

 Kyle - Because they were moving parallel to each other, my guess is very high flying planes or jets. If so, they were probably military aircraft, since most commercial aircraft star in a line of traffic flights. I have seen this activity before and due to the high altitude, no sound present makes the experience all that more errie. Did you get a look at them in a scope or binos? If so, navigation lights should have been seen. If not - ALIENS.

   Mr Q
 

Now that you mention it, yes, I've seen something like that.

Lets see...it would have been...last Thursday, July 3.  Right around 10:30 to 10:45.  That's p.m., of course.  I was jumping around in Scorpius and saw these two dots.  One behind and to the left of the other.  Both were moving at the same speed and appeared to move parallel to each other.  I couldn't see them with my naked eye.  That's not saying much though.  And in the scope, each still looked as small as a satellite with no blinking lights or anything.

At first, I said to myself I would have to get on NASA's website and check out the ISS and any possible shuttle missions.  But then I decided that I couldn't have just seen the ISS and any shuttle preparing to link because I thought it was in the wrong part of the sky.

I thought that the orbit of the ISS took it from northwest to southeast in the part of the country I call home.  I saw these in the SSE and moving ENE.  Well, that was through the scope.  Everything is up-side-down, backwards, left is right, right is left, etc.  I'm still trying to get my mind callibrated to that when I'm viewing.  Anyway, I have had the opportunity to see the ISS pass overhead and it WAS traveling in a path from the NW to the SE.

I have never seen two satellites travel together like this.  What did I see?  And, NO, I'm not suggesting UFO's.  I don't want to get that started here.  There's already numerous other threads dealing with THAT subject!

Two possibilities are a two satellite NOSS "constellation" and the GRACE satellite pair.

http://www.satobs.org/noss.html

http://www.csr.utexas.edu/grace/

Dave Mitsky

Thanks Dave for the info!! 

From what I can read, although I'm still trying to learn how to interpret quite a bit of the info given in the readings, I'm leaning more toward the satellites I observed being the 3rd Generation NOSS satellites.

I truly appreciate the links you gave.  I'm going to go back and read it all again.  I had never seen two satellites travel in the manner I described and had kind of written it off as simply being something cool to see.  Now, I have more to go on!

It finally cleared last night for the first time in many days, or at least somewhat, since the transparency left a lot to be desired, so as the moon was setting I drove to the ASH Naylor Observatory and did a bit of observing with our 17" f/15 classical Cassegrain. 

Of course, Jupiter, being just past opposition, was my first target.  The seeing was rather poor, although I did catch a glimpse of the GRS as it was egressing.  (The GRS transited the CM at 3:38 last night.)  I then moved on to some bright summer DSOs. 

While I was looking at the open cluster M11 at 162x (40mm University Optics MK-70), I noticed a very dim satellite moving slowly through the cluster.  At first, I thought that it might be a geosat, since they tend to populate that area of the sky.  As I watched, I noticed two other satellites moving in tandem with it, forming a very flattened isosceles triangle, which led me to assume that I was watching a NOSS triplet, but this was by far the dimmest NOSS pass that I had ever seen.  Some NOSS triplet passes are visible to the naked eye and, in fact, the first time I saw a NOSS pass was naked-eye at the 1995 Mason-Dixon Star Party.  I've also observed some passes that required binoculars to be seen.

I also observed a nunber of binary stars including Pulcherrima (Epsilon Aurigae), 15 Aquilae, Albireo (Beta Cygni), Almach (Gamma Andromedae), the carbon star V Aquilae, and M15, M22, M31, M56, M57, and the Double Cluster before calling it a night.

Dave Mitsky

I love to teach my kids and friends about the stars!  It's very exciting for them to spot satellites while we're star gazing.  On July 13th 2008 at approx. 11:00pm. in Oconomowoc, WI, we spotted a double set of satellites traveling at same speed across entire sky, they were ? 4-5 degrees apart (approx a fist width at arms length), and one was following almost directly behind the other north to south.  It was fantastic and I've also wondered if anybody has seen this or 3 or more travelling together. I've probably seen 3 or 4 hundred, many crossing paths, but this was first in sync one behind the other.

Thanks for sharing,

My first sighting of the NOSS satellites was while I was observing with a friend in Pawley's Island, SC. We watched three satellites cross the sky. The lead pair was approximately 3 or 4 degrees apart, running side by side. The third was maybe 6 to 8 degrees behind, following the lead pair. We were mesmerized by the sight, and wondered what they were, until I remembered a post that Dave Mitsky had made about the NOSS satellites. A quick check on the internet confirmed that the trio was definitely of the Naval Ocean Surveillance System.

Thanks,

I'll check 'Heavens Above' to see if they'll locate NOSS for me.

Keep looking up,

Tony

My astronomy professor gave us an easy way to distinguish between a satellite and a plane. He said if the light is blinking while it moves across the sky it's a plane. A satellite just looks like a slow moving star, but it won't blink like a plane does. I like to stargaze and see if I can see any satellites, its fascinating for me to see something actually moving through space that is close enough for us to see with our naked eye. This summer when I had the time i searched for them and successfully found three. The first one I found was a greenish colored spec of light moving through the sky. Unfortunately I can't recall what it was moving through of even the direction really. I vaguely remember that I was looking at Leo (this was back before it set early in the evening and you could easily see Saturn and Mars near Regulus) and that it seemed to float northwest of that constellation. The second one I saw was very different from the first one. I was walking my dog one night and I just happened to look up at Ursa Major (the arch of it pointing up like this \ and went down. Sorry, not so great with direction quite yet) and saw a star that didn't belong. I was puzzled, instead of the usual seven there were now eight stars! But then I noticed that the one that didn't belong was moving, faster than the first satellite I had seen. And it was very bright, even in the light-polluted sky of Chattanooga, TN, which was why I had first mistaken it for a star. I caught sight of it in the middle of the "handle" of the dipper and it moved down (the best I can say direction wise is it moved southwest from that point-into the dipper part of the constellation). I'm still very puzzled by it, it didn't blink like an airplane would and if it had I would have thought I would have been able to see it considering it was so bright. I watched until I couldn't see it past the trees. The last one I've seen lately happened about a month ago when I came back to wonderful dark Texas and saw a faint white light moving west through Lyra (Vega being at the top right-hand). 

 Sorry for such a long post, I just wanted to be through in my descriptions in case anyone knew what these were :) Hope this all helped!

awesomeajax:

I just wanted to be thorough in my descriptions in case anyone knew what these were :) Hope this all helped!

They were all satellites. As you may already know, not all satellites appear with the same surface brightness. Some will look like dim stars moving across the sky, while others will appear brighter. Sometimes, you will see one that is faint, but then it will brighten. This is what is called an iridium flare.  Occasionally an antenna on the satellite will reflect sunlight directly down to the Earth, these reflections can be as bright as -8 magnitude, and usually last for just a few seconds. When not flaring, the satellites are often visible crossing the night sky at a typical magnitude of 6, similar to a dim star.

To expand a bit on what Kevin mentioned, some satellites other than the ones in the Iridium series can flare as well, e.g., the Keyhole and Lacrosse spy satellites.

I've seen a number of non-Iridium flares including ones from the UARS and USA 1, if I recall correctly.

Dave Mitsky

In fact, just about any payload with solar panels or can flare.  There are many such payloads in sunsynchronous orbits.  With the operational ones, the solar panels are pointed in the direction of the Sun (or perhaps sunward but actually tilted towards the center of the Earth, like most geostationary satellites).  So that really narrows down the conditions for getting flares.  Hubble Telescope can flare off its aft shroud as well as solar panels.  Iridium satellites can flare off their solar panels as well as their antennas.  (The solar panel flares are less reliable.  A program called Iridflar.exe, and possibly others, gives predictions for Iridium solar panel flares as well as the regular antenna flares.)  Another flaring satellite, long out of service but stable, is Seasat.  I've seen it do so a couple of times in the last week or so.  Some recently launched ones that flare are called SkyMed.  The Grace pair can flare, as can the NOSS pairs and the remaining triplet.  Lacrosse satellites can flare quite brightly and are generally bright all of the time.  Lacrosse 5 is different from numbers 2 through 4 because it's white instead of yellow, and sometimes it disappears suddenly.

I want to add a footnote about distinguishing airplanes from satellites by airplanes flashing.  Of course that's true, but from time to time there are tumbling payloads flash rapidly enough to seem like maybe they could be airplanes.  Iridium 920 is one such.  In binoculars and telescopes one can sometimes observe distant Centaur upper stages that are tumbling and flashing close to once per second.  Right now there's a recently launched low-earth-orbit launch vehicle (SAR Lupe 5 Rk, 33245, 08-36B) that is flashing with a half-second period.

Ed Cannon - Austin, Texas, USA

 I found a really great site that tracks the International Space Station. We actually saw it about a week ago and this website confirmed our suspicions. 

http://isstracker.com/

We've been tracking it ever since. Have yet to see it again, we're in an extremely remote part of Texas, but hopefully we will soon!