Starlink Satellite Train Explained: Decoding the Linear Formation in the Sky

Photo of author
Written By Viktor

Product manager by day, Starlink enthusiast by night.

People all across the globe have reported seeing a straight line of white dots traveling across the night sky.

Before you freak out now: no, aliens are not taking over just yet. Instead, the phenomena, made possible by SpaceX’s Starlink, is commonly referred to as satellite trains.  

In this article, I’ll detail what Starlink’s satellite trains actually are, how they can be spotted, and how many of those are roaming earth at any given time.

What Is a Starlink Satellite Train?

Starlink satellite trains are a collection of satellites that roam low-earth orbit (LEO) at close distances to each other.

This is how a satellite train I recently spotted from my backyard (sorry for the lackluster video quality) looks like out in the wild:

The fact that you can see Starlink’s satellites isn’t anything unique to the internet service provider (ISP). Whether it’s the International Space Station (ISS) or even the James Webb telescope, objects in space are visible due to the sunlight they attract.

However, what separates Starlink from other objects in space is the vastness of its constellation, which currently boasts close to 3,600 satellites in orbit.

SpaceX, as you can see on our dedicated launch statistics page, normally deploys around 50 or so satellites during a single launch.

Starlink has since reached the maximum number of version 1.5 satellites permitted by the FCC. It has now gone over to exclusively launch its so-called V2 Mini satellites – normally in groups of 20 to 22.

Those satellites initially orbit earth in multiple groups and take advantage of a concept called plane drift, thus enabling Starlink to cover various parts of our globe.

The initially grouped together satellites then form the trains that we see back down on earth. Unfortunately, that sight is only of temporary nature.

According to Harvard scientist Jonathan McDowell (see tweet above), Starlink’s satellites remain in their train-like position for a few months after which they each go their separate ways.

More precisely, satellites operate in what McDowell calls the “intermediate orbit”, namely around 400km (~248 miles) distance to earth.

They then rise to an operational orbit, at a height of 550km (~341 miles), using the satellite’s thrusters. Around 80 or so percent of all satellites reach their designated orbit location while the rest malfunction for a variety of different reasons.

Luckily, people do not need to worry, though. The overwhelming majority of Starlink’s satellites burn up when re-entering earth’s atmosphere.

This is also why the trains have ‘holes’ in them, meaning the distance between each satellite isn’t equal as some have already departed for operational orbit.

Why Are Starlink Satellites in a Train?

The reason why Starlink’s satellites are roaming Earth in a train-like structure is manifold. First of all, releasing them in one sequence simply minimizes collision risk and thus space debris.

Here you can see a release sequence for Starlink’s Gen2 Mini satellites, which are grouped together as one:

Over time, those satellites are separating from each other, forming the train-like structure that you can then see back down on Earth.

Apart from the safety aspect, fuel efficiency is also of importance. Each satellite only has a limited amount of fuel, so sending them immediately to their designated orbit (550km) would use up even more of it.

Being grouped together in a train early on also allows ground controllers to more easily track them and make precise orbital adjustments. 

For example, satellites can malfunction sometimes for different reasons. Being located in lower orbital shells and within the confinement of the train thus enables them to deorbit faster.

How to Spot a Satellite Train

There are a variety of online tools that enable you to track Starlink satellites as they roam the skies. The one that I used can be accessed here.

Simply add your country and city of residence, or alternatively longitude and latitude, and the tool shows you when to expect a satellite train.

Keep in mind that all of these tools are mere approximations given that their creators do not have access to real-time navigation data.

For example, Starlink relies on an autonomous collision avoidance system that changes a satellite’s direction whenever necessary.

SpaceX previously revealed that its Starlink satellites performed over 26,000 collision avoidance maneuvers in a span of two years (11/2020 – 11/2022). Therefore, on any given day, its satellites perform 75 maneuvers.

Another aspect to keep in mind is your environment. Satellite spotting works best in areas of low light pollution. So, small towns and nature are likely your best bet to spot a train of satellites.

Additionally, you want to make sure that the weather is on your side and thus offers a clear and cloud-free view of the night sky.

Lastly, keep in mind that the satellite train will only be visible for a few minutes, so simply being on time is essential to a great viewing experience.

How Many Starlink Trains Are There?

At any given time, there are a handful or more satellite trains that are visible to the human eye. The above-mentioned tracker page highlights their current location and projected directions.

starlink satellite train locations

Generally speaking, Starlink and SpaceX are incentivized to have as few spottable satellite trains as possible.

For once, satellites in intermediate orbit do not operate on the required frequency bands to provide internet services to customers back down on earth – thus not making money for Starlink.

Another aspect to consider is the mounting political pressure Starlink is facing. For example, its satellites are causing streaks in telescope images.

The fact that those trains are visible without relying on advanced technology only amplifies those concerns, regardless of how valid they may be.

Luckily, SpaceX has vowed to address those issues. In July 2022, it published a document highlighting the initiatives it already underwent and plans to undergo to mitigate the negative effects of its constellation.

Those include using a darker coating, adopting specular surfaces to deflect lighting into another direction, optimizing flight operations, and so forth. SpaceX also remains in constant exchange with those very same astronomers to ensure whatever it implements addresses their concerns.

37 thoughts on “Starlink Satellite Train Explained: Decoding the Linear Formation in the Sky”

  1. First time here but for sure not the last. I really enjoyed your article regarding the Elon Musk Starlink Satellite Train explanation. Fascinating space insights and facts to learn about and sit in awe. Keep up the good work!

  2. Thanks for the excellent explanation of what the Starlink trains are. We saw it for the first time last night and were impressed with the sight.

  3. Just saw the train tonite while I was out grilling. Was blown away and came in to ask my son what it might be – he said his friend had posted that he saw the same thing. We researched, and I found your informative article. Thanks!

  4. Thank you for your article. I saw my first Starlink Train last night. What a sight! As it went directly over me the lights were blue. Is this part of the changes they are making? It was quite beautiful. I am curious to know the speed at which the trains travel. Do you happen to know?

    • Hi Kathleen, can’t comment on the light. However, the newer satellites should have not reflect as much, so glad that you still saw them! As far as speed, it takes SL satellites around 90 minutes to orbit around the earth. At an altitude of ~550km, that means they travel at a speed of approx. 7.7 km/s or 27,770 km/h (7.7 km/s x 3600 sec).

  5. On August 11, 2023, about 21h30, I saw a Starlink Train over Hot Springs, SD. This was while camping, and sitting outside watching for the Perseid meteors. Had never heard of such a thing as this long column of blue dots, and thought it was a drone constellation from the Mt. Rushmore lighting display. But then, by coincidence, the next day I was researching Starlink Mobile (RV) service, and I came across the correct explanation.

  6. Saw satellite train over rural Missouri at 9.36 pm, on August 16. Had no idea what I was seeing. Was hesitant about saying anything until I found your site. Fun.

  7. I just saw this train in the clear skies of New Jersey this evening. I was just star gazing, but was treated to this amazing sight! Great article btw!

  8. I was with a family group sitting around a bonfire, and the discussion had just turned to the possibility of extraterrestrial life. David, one member of our group, was arguing strongly that spaceship Earth was all alone when someone else spotted a strange set of moving dots high in the sky. Were they alien spaceships coming to prove David wrong, perhaps abduct him to prove it? He certainly fell silent, perhaps contemplating that possibility. Posing pictures of this phenomenon on Facebook led to a tip the next day, which led to this page. Thanks for clearing up the mystery.

  9. Also in New Jersey. Labor Day party grilling and hanging out. A group of about 14 people saw the train in the sky. About 20 minutes later (or less) we witness the meteor – a green fireball glowing as it came down to earth. (I did some research and determined it was somewhere overhead Hamilton, Maryland.)

  10. Just spotted one for the 2nd time over Apache Junction AZ 9/06 2023at 8 PM. First time seeing one was December 03 2022 same place . So cool Thank you for your write-up

  11. Viktor, I saw a Starlink constellation on Sunday, Sept. 3, directly overhead at 9pm on Bethany Beach, DE. One of the persons I was with pointed up and then explained what it was after watching me for a minute marveling at it. I read a year ago that Starlink is a network of crosshatching orbiting satellites, I figured it was a pre-orbital pattern, which you confirm above.

    I wonder about the astronomer’s who are complaining, considering airplanes, meteors, other satellites, and now drones filling the sky. What is your opinion? Are they just picking on Musk or is it a real complaint?

    • Hi Ron, the concerns that astronomers voice are somewhat legit. That said, a few points:

      1) Starlink is doing a lot to diminish the light that its satellites reflect, for example applying darker coating. Their newer Gen2 sats specifically address some of those problems (feel free to have a read here:
      2) You can use various computer vision techniques to get rid of the streaks in images.
      3) Many of most important and powerful telescopes, such as NASA’s James Webb or the proposed Lunar Crater Radio Telescope (LCRT) on the Far-Side of the Moon, are located above the altitude of Starlink sats.

      If there’s one thing that SpaceX is great at, then it’s learning from past mistakes. I’d expect this issue to be figured out over time.

  12. Excellent article. It explains what we saw sitting around a campfire on our farm in Olean NY at approximately 9 pm last night. I’m used to seeing the space station and other satellites at much higher orbits and last nights “string of 20 pearls” seemed at a much lower orbit. Now I know why. Thank you.

  13. A month ago, the kids came in yelling about a space dragon… come look, come look. I didn’t get away from under the trees in time to see it. They were genuinely upset that i missed it, it had to be aliens. I discarded that event until tonight when another batch came across, this time i got to see it, awe inspiring for certain. This time i did some searching and we now know what they are. Musk is certainly the Tesla of our age (minus the destitute part). Wow.

  14. Just outside of Allentown PA we saw a Starlink train pass overhead this evening. Really neat to see! It raised a question: about how long is a typical “train” way up there, and what is the distance between the individual “dots?” I know that will vary, But can you give an example?

    • Hi Chuck, Starlink normally deploys 20 to 23 V2 Mini satellites, so that should roughly be the train’s size. That said, satellites do have varying trajectories, depending on whether they function properly, designated orbital shells, and so forth. So, there’s no generalizable answer to that question except that it depends.

  15. I saw the train a couple of nights ago
    I find it really hard to believe that I can easily see such small objects
    from 248 miles away


Leave a Comment