<p>Yes, they can.  The ships that visit the ISS often orbit near the station for several hours before docking.  Further, there are several satellites that travel in pairs or trios with other satellites.  The nearer the satellites are to earth, or the farther apart they are, the more difficult the task of maintaining spatial relationships between the spacecraft. This is because the spacecraft must be in the same orbital plane to travel together.  The most common configuration is where they are in the exact same orbit, with one satellites a few seconds ahead of the other along the same path.</p>

CC BY-SA 3.0
2016-08-24T21:59:35.093Z
2016-08-24T21:59:35.093Z
Byron Jones
<p>We recently had a similar experience while staying in the Massa Lubrense region of southern Italy near Naples around July 10th, 2019. What we saw were about 40 or more satellites orbiting at what appeared to be the same velocity, as a group. There were 4 of us who witnessed this and had never seen anything like it before. They were not airplanes as there were no flashing lights. They appeared to be moving in unison as the relative distance between them did not change. They were moving at the approximate speed of an orbiting satellite (by comparison of ones I have seen before) and did not change direction while we were watching. I started counting and once I reached 40 they became difficult to see so I stopped counting. By the strict sense of the definition, yes - these were UFO's, however I don't think they were piloted by aliens. I do think they were satellites.</p>

CC BY-SA 4.0
2019-07-31T17:52:42.653Z
2019-07-31T17:52:42.653Z
Paul Lindquist
<p>I can't answer your second question. Do you have a video of them? Why do you think they were in orbit? Are balloons a possibility? You say 25 or 30, did you observe them simultaneously or did they blink in and out? How long did you observe them, how far did they travel, and various other questions would need answers to even speculate... Now as far as your first question, the answer is no and yes. A ballistic orbit (not powered) will circle the Earth, and by "circle" I mean the path will be a great circle (which you can look up). This means that no two orbits (at the same altitude) are parallel everywhere. If they seem to be traveling together in parallel now, then their orbits must cross twice for every orbit around the Earth. So IF they were at the same altitude, they would have to be in orbital paths that intersected, so they would have to be staggered so as not to collide. At different altitudes, you can stack any number of satellites above one another. But it's very unlikely that this is what you saw, there's no reason to set up two dozen or more satellites in this type of configuration. Just based on your comments, perhaps what you saw was the break-up of a satellite. 25-30 satellites is an enormous number and the cost would also be extravagant (unless they were mini-satellites).</p>

CC BY-SA 3.0
2016-08-26T22:41:39.543Z
James - ok. Li - I went out afterward to take a video, figuring that whatever it was was orbiting the earth and would return. But the two of us didn't see it again.
2inLancaster
CC BY-SA 3.0
2016-08-26T22:47:48.917Z
Oops- timed out:   James - thanks- so not the breakup of a satellite, space junk, meteors, etc. Li - Two sensible adults saw the lights. I went out afterward to take a video, figuring that whatever it was was orbiting the earth and would return. But I didn't see it again. They moved as a group, did not blink, and were equally bright, suggesting that they were at the same altitude. They were about twice as large as stars.  Very odd.
2inLancaster
CC BY-SA 3.0
2016-08-21T20:39:02.787Z
2016-08-21T20:39:02.787Z
Li Zhi
<p>As a guess, I'd say you were probably looking at a group of aircraft flying together, possibly helicopters. Usually you can tell aircraft at night because the have red and green lights and anti collision lights that blink, but I have occasionally observed aircraft flying with landing lights on, and could not make out the other lights until they were closer, or they had changed direction, making them stand out.</p><p>I've never seen a UFO, although I once mistook Venus for one.</p>

CC BY-SA 3.0
2016-08-25T00:59:29.713Z
It's quite possibly just one aircraft: a large jet at cruising altitude with all its lights on (landing lights, logo-illumination lights, wingtip lights, etc) can easily be mistaken for a group of UFOs flying in formation.
Mark
CC BY-SA 3.0
2016-08-21T21:20:27.380Z
2016-08-21T21:20:27.380Z
Howard Miller
<p>Last night we saw a large cluster of what looked like exceptionally bright stars that moved, as a group, across the night sky in Lancaster, PA. It was about 9:15 pm, and they moved roughly from SW to NE. There were 25 or 30 of them. They moved as quickly as a satellite I once saw, but were bigger and brighter. They were soundless and did not blink, and the relationships between the lights changed slightly as they moved.</p>

<p>We don't believe in UFOs, but can't we find any explanation via google. </p>

<p>Can that many satellites move as a group?</p>

CC BY-SA 3.0
2016-08-21T18:44:10.930Z
There are a number of questions like this. The stock answer is "We don't know" No natural phenomenon is exactly as you describe. Not satellites, planes meteors or re-entering space junk.
James K
CC BY-SA 4.0
2019-11-20T12:02:46.810Z
Any chance it is the Space X starlink . https://earthsky.org/space/wow-photo-video-spacex-starlink-satellite-train ?
arunvg
CC BY-SA 4.0
2020-01-26T10:49:10.990Z
@arunvg The question was posted here in 2016. Considering that the first Starlink launch was in 2018 (of just two test satellites), I think it's fair to say that it is likely not  Starlink. However I can see why the mixup occurred, with all of the Starlink questions.
Barry Jenakuns
CC BY-SA 4.0
2020-02-06T13:55:10.520Z
Hey 2inLancaster, if my answer is sufficient, could you mark this question as answered?  Thanks!
Byron Jones
<orbit><amateur-observing><artificial-satellite>
Can satellites travel in clusters?
2inLancaster
# Can satellites travel in clusters?

(Asked by: username_0 on 2016-08-21)

Last night we saw a large cluster of what looked like exceptionally bright stars that moved, as a group, across the night sky in Lancaster, PA. It was about 9:15 pm, and they moved roughly from SW to NE. There were 25 or 30 of them. They moved as quickly as a satellite I once saw, but were bigger and brighter. They were soundless and did not blink, and the relationships between the lights changed slightly as they moved.

We don't believe in UFOs, but can't we find any explanation via google.

Can that many satellites move as a group?

**Tags:** orbit, amateur-observing, artificial-satellite
> **Comments:**
> **username_1**: There are a number of questions like this. The stock answer is "We don't know" No natural phenomenon is exactly as you describe. Not satellites, planes meteors or re-entering space junk.  
> **username_2**: Any chance it is the Space X starlink . https://earthsky.org/space/wow-photo-video-spacex-starlink-satellite-train ?  
> **username_3**: @arunvg The question was posted here in 2016. Considering that the first Starlink launch was in 2018 (of just two test satellites), I think it's fair to say that it is likely not  Starlink. However I can see why the mixup occurred, with all of the Starlink questions.  
> **username_4**: Hey 2inLancaster, if my answer is sufficient, could you mark this question as answered?  Thanks!  

---

## 4 answers

### Answer by username_4 on 2016-08-24. Score: 4

Yes, they can. The ships that visit the ISS often orbit near the station for several hours before docking. Further, there are several satellites that travel in pairs or trios with other satellites. The nearer the satellites are to earth, or the farther apart they are, the more difficult the task of maintaining spatial relationships between the spacecraft. This is because the spacecraft must be in the same orbital plane to travel together. The most common configuration is where they are in the exact same orbit, with one satellites a few seconds ahead of the other along the same path.


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### Answer by username_5 on 2019-07-31. Score: 3

We recently had a similar experience while staying in the Massa Lubrense region of southern Italy near Naples around July 10th, 2019. What we saw were about 40 or more satellites orbiting at what appeared to be the same velocity, as a group. There were 4 of us who witnessed this and had never seen anything like it before. They were not airplanes as there were no flashing lights. They appeared to be moving in unison as the relative distance between them did not change. They were moving at the approximate speed of an orbiting satellite (by comparison of ones I have seen before) and did not change direction while we were watching. I started counting and once I reached 40 they became difficult to see so I stopped counting. By the strict sense of the definition, yes - these were UFO's, however I don't think they were piloted by aliens. I do think they were satellites.


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### Answer by username_6 on 2016-08-21. Score: 1

I can't answer your second question. Do you have a video of them? Why do you think they were in orbit? Are balloons a possibility? You say 25 or 30, did you observe them simultaneously or did they blink in and out? How long did you observe them, how far did they travel, and various other questions would need answers to even speculate... Now as far as your first question, the answer is no and yes. A ballistic orbit (not powered) will circle the Earth, and by "circle" I mean the path will be a great circle (which you can look up). This means that no two orbits (at the same altitude) are parallel everywhere. If they seem to be traveling together in parallel now, then their orbits must cross twice for every orbit around the Earth. So IF they were at the same altitude, they would have to be in orbital paths that intersected, so they would have to be staggered so as not to collide. At different altitudes, you can stack any number of satellites above one another. But it's very unlikely that this is what you saw, there's no reason to set up two dozen or more satellites in this type of configuration. Just based on your comments, perhaps what you saw was the break-up of a satellite. 25-30 satellites is an enormous number and the cost would also be extravagant (unless they were mini-satellites).

> **Comments:**
> **username_0**: James - ok. Li - I went out afterward to take a video, figuring that whatever it was was orbiting the earth and would return. But the two of us didn't see it again.  
> **username_0**: Oops- timed out:   James - thanks- so not the breakup of a satellite, space junk, meteors, etc. Li - Two sensible adults saw the lights. I went out afterward to take a video, figuring that whatever it was was orbiting the earth and would return. But I didn't see it again. They moved as a group, did not blink, and were equally bright, suggesting that they were at the same altitude. They were about twice as large as stars.  Very odd.  

---

### Answer by username_7 on 2016-08-21. Score: 1

As a guess, I'd say you were probably looking at a group of aircraft flying together, possibly helicopters. Usually you can tell aircraft at night because the have red and green lights and anti collision lights that blink, but I have occasionally observed aircraft flying with landing lights on, and could not make out the other lights until they were closer, or they had changed direction, making them stand out.

I've never seen a UFO, although I once mistook Venus for one.

> **Comments:**
> **username_8**: It's quite possibly just one aircraft: a large jet at cruising altitude with all its lights on (landing lights, logo-illumination lights, wingtip lights, etc) can easily be mistaken for a group of UFOs flying in formation.  

---

