The 60 Starlink satellites parading across the sky make an incredible sight, but some skywatchers wonder at what cost to the night.

It's a safe bet to say no one had ever seen anything like it — 60 satellites chugging across the sky in a straight line like some outer space choo-choo. We're grateful that Dutch satellite sleuth Marco Langbroek captured video. If nothing else, it will calm those who were convinced they were seeing a UFO. But as is nearly always the case, there was a more prosaic explanation: Elon Musk, SpaceX founder, sent the first volley of what will become a megaconstellation of 12,000 Starlink satellites to provide broadband internet service for under served areas of the globe.

A video of SpaceX Starlink satellites as viewed from the Netherlands on May 24, 2019.
Marco Langbroek

That's right. 12,000. If all goes according to plan, SpaceX will send up fusillades of the satellites on its Falcon 9 rocket multiple times a year over until the entire constellation is complete, which will take about 9 years. Fortunately or not, depending on how you feel about sending this many machines into orbit, the incredible sight will be repeated 4–5 times again in 2019 alone. That means lots of opportunities to see the heavenly procession in case you were clouded out this time around.

Successful deployment of Starlink satellites in orbit. We see all 60 folded up tight. They will soon drift away from one another like the expanding bellows of an accordion to form the remarkable train in the sky.

During the initial orbit, the Starlink train passed over northwestern Europe at an altitude of just 440 km) and formed a neat line about 7° long that resembled a ticker tape (if anyone still remembers those) or the crawl under the talking heads on the nightly news. At the time, the satellites ranged in brightness from 1st to 3rd magnitude and were easily visible with the naked eye.

Ducks in a row
A single frame from Marco Langbroek's video captures the amazing sight of nearly 50 satellites in a straight line moving across the sky.
Marco Langbroek

Since then, the satellites have been firing their thrusters to climb to an operational altitude of 550 kilometers with an orbital inclination of 53° — steep enough for most of the world to connect to the internet as well as see its orbiting providers.

Threading the heavens
Pardon my grain! Even this 1-second exposure at ISO 32,000 was too long to properly capture the Starlink train, but you get the idea. I caught it moving through Coma Berenices May 25, 2019, around 11:25 p.m. CDT. Multiple satellites occupy each segment of the streak. The unearthly display took about 5 minutes to cross the sky.
Bob King

I got my first look during a beautiful high pass on May 25th and couldn't believe my eyes. I first spotted the 60 satellites as a freaky thread of light rising straight up through Leo's tail. As it drew closer I could faintly make out dozens of tiny lights between 4th and 5th magnitude lined up like geese in flight. When low in the west, the group sight spanned some 10° (two fists) but closer to 20° when overhead. Incredibly, individual or clusters of the objects would briefly flare and fade — some as bright as magnitude 2 — which made the train sparkle like a frost-covered twig in sunlight.

Starlink satellite train with flaring on May 26th.
Movie Vertigo

The view in binoculars was even more striking and looked exactly like the video, with satellites streaming by so quickly I could hardly count them. Over time, as they've reached altitude, the Starlink birds have faded considerably . . . and spread out. What used to take a few minutes for a pass now takes close to half an hour! During a 10:55 p.m. pass on May 28th, none were visible with the naked eye from my home (limiting magnitude 5 at the time), though I did see one or two flare to 4th magnitude in binoculars. Most glimmered between 6th and 8th magnitude and either appeared singly or in small bunches of two to four. I looked for nearly 20 minutes at a train more than 100° long.

If you like satellite watching, Starlink is a boon. But if you worry about humans polluting the sky with space junk, you've probably already slammed your fist on the table while reading this. Either way, the design life for the birds is around 5 years followed by a tidy and safe burn-up in the atmosphere. All are equipped with a satellite-avoidance technology to prevent crashes that might lead to the release of orbital debris.

An arm to the sun
In this conceptual view, each Starlink satellite unfurls a single solar panel.

Starlink satellites have a folding design that allows 60 at a time to be packed as tight as sardines in a Falcon 9. Once in orbit, each deploys a single solar panel to generate the electricity to power a krypton ion engine similar to the xenon ion engine used by NASA's Dawn spacecraft to travel to Vesta and Ceres. Although krypton is less efficient than xenon, it's also cheaper — a consideration if you plan to launch thousands of satellites.

Six more launches of 60 will be needed to initially activate the system. Because the satellites will communicate by lasers, the network is expected to provide higher internet speeds than what can be achieved on the ground with fiber optic cable. Light travels considerably faster across the vacuum of space than it does through glass fibers.

After 12 launches, the constellation will begin to provide significant coverage. The long-term plan will roll out in three phases with satellites launched into 53° orbits in three major orbital planes:

  • ~1,600 satellites in a constellation at an altitude of 550 km
  • ~2,800 objects at 1,150 km
  • ~7,500 satellites at the lowest altitude of 340 km
Spear of satellites
The Starlink satellite pack crosses the zenith near the handle of the Big Dipper during the May 25th pass. Exposure: 1 second at ISO 32,000.
Bob King

How to See Starlink

The easiest way is to go to Heavens Above and select your location. Return to the main page and click on the Starlink leader and Starlink trailer links. These are the first and last satellites in what has now become a long procession. The leader is a several minutes ahead of the main group, so if you see just one or two at first, stick around. The others will follow along the same path.

Starlink Satellite Tracker is super-easy to use. Select your city from the drop-down list or input your latitude and longitude if your city's not on the list. You'll get a list of passes and where to look. The site also provides a live map showing Starlink's location. If you don't know your latitude and longitude, click here. also shows passes and information for the Starlink Group. Just type Starlink in the Find a Satellite box. This will show the next pass. For a list of passes, click the10-day predictions link.

CalSky is another excellent site. Like the Heavens Above website, CalSky offers printable sky maps showing the satellite track. Sign in and select your city under the Setup link, then click the Satellites link. In the more detailed menu, click on Sat-Library. In the box at left, type Starlink for satellite name. Go back to the links under the heading and click Selected Satellite. In the yellow Satellite Menu box to the right, click Sighting Opportunities. Scroll down to see a list of local times, directions, and altitudes. Click Star Map to get a map of the path for a particular pass. The next time you come back you'll only have to click the Sighting Opportunities link — the site remembers the rest.

Frequent flaring
Although the satellites are fading as they're moving to a higher altitude, some still flare under the right conditions as seen in this May 28th image. "Several briefly flared in succession to magnitude 1.5 to 2, all in the same sky area in Northern Corona Borealis, corresponding to the azimuth opposite that of the Sun," writes Langbroek. 
Marco Langbroek

Be sure to go out a few 5–10 minutes beforehand to dark-adapt your eyes. Until the next launch, binoculars are essential for seeing these. Few if any are visible with the naked eye unless they flare. If you live near a big city it will be an even greater challenge, so try this: Check the Starlink path on a map and note when a pass takes it close to a bright star.  Put that star in your binoculars then wait and watch for them to zip by. On May 28th I was lucky enough to have Polaris as my guide.

A Million Points of Unwanted Light?

Although the sight of five dozen satellites in a row will take your breath away, not a few of us are concerned about the volume of traffic over our heads. Yes, there's a lot of space up there. We get it. But in 9 years, when 12,000 of them will be crawling the skies like so many ants, will it detract from the sight of the stars at night? Some will say that most of the units will be too high to see with the naked eye, and my May 28th observation seems to be proving the point, but that lowest and most populated belt — the 7,500 at 340 kilometers altitude — will almost certainly be visible. Not just in bright twilight either. My May 25th sighting was made at 11:25 p.m.

If you're an astrophotographer, trails from Starlink may be unavoidable and require frequent and deft use of your photo program's cloning tool. For professional astronomers, imaging headaches undoubtedly lie ahead. For the visual observer, will it mean a constant reminder of machines on parade while seeking the solace of a dark sky?

In response to online concerns from amateur and professional astronomers, planetary astronomer Alex Parker tweeted his concerns that "If SpaceX launches all 12,000, they will outnumber stars visible to the naked eye," and estimates that "at midsummer midnight in Seattle about 500 of them will both be above the horizon and directly illuminated by the Sun."

Web around the world
When up and running, Starlink will provide internet access to locations across the planet.

Musk has already talked to his staff about making Starlink satellites less shiny. The team can also tweak the satellites' orientations to further reduce reflectivity if astronomers need to make sensitive observations. Musk has also addressed any potential conflicts with radio astronomers, tweeting that Starlink will "avoid use of certain lower Ku frequencies specifically for radio astronomy."

There are still many unknowns and a few troubling "knowns" as well. Starlink is only the first wave. Other companies plan to compete with SpaceX for your internet dollar by launching their own satellite networks. Amazon recently announced plans to launch a broadband internet constellation of 3,236 satellites called Project Kuiper in the near future. More are in the works including OneWeb and Telesat.

Despite the thrill of seeing a unique human-made wonder like Starlink and the understandable need for internet service in remote locations, some of us are worried just where this road is taking us. This statement from the International Dark-Sky Association (IDA) sums up many skywatchers' concerns in a nutshell.

Addendum, May 30: I just received this statement from the National Science Foundation's spokesperson Amanda Greenwell regarding radio astronomy and Starlink. It reads in part:

"NSF is committed to ensuring the scientific community’s access to vital portions of the radio spectrum required for research purposes. We have been working with SpaceX to finalize an agreement related to management of the affected portion of the radio spectrum and can provide more information after that agreement is finalized."


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May 29, 2019 at 12:58 pm

Bob King, I have been following various reports on this *satellite adventure*. Here is my thought on this. I periodically see polar orbiting and equatorial orbiting satellites pass over while stargazing. Some flash brightly into my eyepiece using the telescope. Just think when a stream of 12,000 do that.

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Bob King

May 29, 2019 at 10:00 pm

Indeed — just think! It'll be like disco ball.

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May 29, 2019 at 1:01 pm

I have seen this chain of lights on 25 may. Two consequent pass. From my point of view (Russia, 57 deg lat, red zone) there is only few satelites visible for naked eye. But with binoculars it's been amazing to watch this!
But this is sadly to see how humanity is moving forward with technology, destroing wonders of nature one by one. The price is heavy.
Sorry for my english...

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Bob King

May 29, 2019 at 10:01 pm

Your English is fine and on point. Thanks for sharing your observation and opinion.

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May 29, 2019 at 7:20 pm

Bob, I was observing at Wagman Observatory that night. I didn't see any train of satellites, but I what I did view was somewhat surprising. I was on the ladder while observing Jupiter, when I turned and looked towards the NE. There was a large oval to round, soft, but bright disk about 5 to 6 minutes of arc in diameter with a with a diffuse, fog-like cloud surrounding it as it moved towards the horizon in the NE. I watched it for 3 to 4 minutes before it disappeared below the horizon. It looked like a comet making an extremely close pass of the Earth. I probably missed much of its path through the sky because the building was blocking my view to the North. This, apparently, was a rocket stage exhaust from the launch. I observed a multiple satellite deployment in the 1980s. I saw two objects moving across the sky very close to together. I grabbed my binoculars and was able to see five objects. Then I viewed a total of 7 through my 8" Scope. It turned out to be two rocket stages and five Russian satellites being launched into orbit. That's what makes visual observing so much fun. You never know what you might see next.

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Bob King

May 29, 2019 at 10:02 pm

I'd love to see something like that. The closest I've come is watching barium releases (long ago) to study the ionosphere.

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May 29, 2019 at 7:23 pm

This is a disaster for earthbound astronomy.

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May 30, 2019 at 1:50 pm

As an amateur astronomer I am always amazed when I see satellites passing in a ‘blink’ across my FOV. It used to be a rare event, but not any more. Now every time I am viewing I see satellites, sometimes half a dozen or more in a single session!

Now, with tens of thousands of new satellites going up I expect to see even more distractions and am NOT happy about that .. no!

Elon is no longer one of my hero’s .. just another money grubbing billionaire...

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May 30, 2019 at 1:52 pm

Hi Bob, I am really shocked. What can we do against it? Elon Musk will ruin the nightsky.

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May 30, 2019 at 5:47 pm

I wonder if professional astronomers will end up using some sort of special occulter that springs into action when a satellite enters the FOV? This would be like StarShade, except for ground-based telescopes. Drones could probably be used to develop such a system. These flying occulters would stay between the scope and the satellite, and could use existing satellite orbit data to get ready for a pass. There would probably need to be some sort of guide scope for the occulter to ensure occulting occurs even if a satellite (or space junk) is not quite where the orbital parameters say it should be.

Bob: I used to live in Fairbanks Alaska. I really enjoyed watching the barium releases into the aurora, launched from Poker Flats.

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Bob King

May 30, 2019 at 8:35 pm

Hi Everett,
Oh my gosh, then you'd have all those drones! I'm guessing that if necessary there would be an after-the-fact software fix to remove unwanted trails. Hopefully, Elon will mitigate the problem by painting the satellites black and orienting them to reduce their shininess. I bet you got to see lots more barium releases than I have when you were in Fairbanks. At least those were one-offs.

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Anthony Barreiro

May 30, 2019 at 5:56 pm

Satellites are already an unwelcome distraction. On May 11 at my astronomy club's monthly public star party on Mount Tamalpais I gave a brief tour of the naked-eye sky to the visitors. After a few minutes one visitor pointed out a third-magnitude satellite passing north through Bootes, and the game was on. Over the next few minutes, different visitors called out four more satellites and the other visitors all tried to see them. I was trying to help the visitors understand how the Earth's rotation and orbit around the Sun determine what we see in the sky and the distances to the stars, but every minute or so our attention was drawn to an artificial satellite in low Earth orbit. When there are hundreds of satellites visible in the sky at any time, it will just be another layer of light pollution.

That said, I am encouraged that Musk has acknowledged the concern and promised to mitigate the brightness of the Starlink satellites at visible and radio wavelengths. I hope that industry leaders and government regulators will heed the final paragraph of the International Dark Sky statement:

"The number of low Earth orbit satellites planned to launch in the next half-decade has the potential to fundamentally shift the nature of our experience of the night sky. IDA is concerned about the impacts of further development and regulatory launch approval of these satellites. We therefore urge all parties to take precautionary efforts to protect the unaltered nighttime environment before deployment of new, large-scale satellite groups."

The key word is "precautionary".

Everybody who wants to preserve a dark night sky should join the International Dark Sky Association:

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Bob King

May 30, 2019 at 8:37 pm

Interesting observation about the public and satellites. Students in my classes love pointing them out, and I've found they can help get people under the night sky, but yes, your point about their power to distract is well-taken.

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[email protected]

May 31, 2019 at 5:58 pm

I do believe that this starlink project is a good thing for a more democratic WiFi but very bad news for astrophotography, which I love to do. Seriously I don't need internet in the woods.

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DL Moonitz

June 1, 2019 at 4:24 am

Satellite-proliferation-mania is going in the wrong direction too fast and with little control, vision or concern for anyone but those with money, influence and power. Starlink appears to be just another commercial venture masquerading as a “Humanitarian” communication satellite network for the “Underserved” areas of the earth’s population. The end-game for the investors has nothing to do with compassion and everything to do with more money, influence and power for the financially and technologically elite. The application is being sold as a ‘commercial’ enterprise but the customers could include, governments, militaries, terrorist exporting/promoting nations.
As for mr. musk, i’d like to see him launch himself into orbit around Jupiter in one of his convertibles, ... without a space suit.

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June 2, 2019 at 12:35 am

Now that all the hysteria is dying down, we can rationally think of solutions.

First off, there ARE technologies right off the shelf to greatly reduce the albedo of these sats, without raising their internal operational temperatures to the point where they become unreliable or have service life affected. There are MANY coatings/anodizing methods to do this.As the first batch of "oops, I forgot about that reflectivity thing" sats orbits decay, they can be replaced with improved low-to-zero reflectivity models.

This NOT an insoluble issue. And anything that shakes up the ISP grip of The Big Boys up and puts more choices in the hands of people in "the last mile" I'm definitely for, as long as it doesn't further crud up our skies.

How happy are YOU with your current ISP? (AT&T, Charter, Spectrum, etc.) If Elon manages to pull this off to where we're paying half of what we're currently being gouged for now, it'll be a success. My understanding of the model is a flat black box on your roof about 4X4 for the receiver.

IF he learns about black/gray anodizing shiny metal, that is... 🙂

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June 2, 2019 at 10:26 am

Well, at least I have amateur astronomy apps, as well as a few shelves of S&T back issues and my favorite books.

Thanks for this article in your blog.

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June 9, 2019 at 11:29 pm

I used CalSky to set up an email notification and finally got a viewing at a reasonable time of night. What I (think I) saw slowly and repeatedly dimmed and brightened, something I never saw the ISS or Shuttle do. Is this expected? If so, what causes this? Or was it just my (and my wife's) imagination?

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Bob King

June 10, 2019 at 3:49 pm

Hi Phil,
Absolutely not your imagination. I saw many of them twinkle as they passed overhead. They may have been slowly tumbling. Others may have been catching the sun with their solar arrays in such a way as to temporarily reflect light your way, producing briefs flares.

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James Daly, Ph.D

June 24, 2019 at 9:15 am

Great comments here!

If I may humbly point out that this isn’t about the Starlink satellites ruining images of the Virgo cluster of galaxies or Messier-8, it’s about forever altering the character of the night sky!

Looking to the stars has inspired mankind for millennia, for countless generations, for thousands of years, with the Greeks, the Babylonians, the Persians looking up, attempting to understand what they saw, to learn about their origins, the place from whence they came, its what gives meaning to our existence! This project, if allowed to come to fruition will forever sully the view that leaves one in breathtaking awe of nature’s majesty, the canopy of millions of beautiful points of light, so distant, yet so clear, beckoning.

This is the province of all humanity and the UN should have been consulted or, at the very least, the signatories to the 1967 Space-use treaty should have been consulted.

The Outer Space Treaty of 1967 which, either was ignored by SpaceX or disregarded entirely, clearly states that
1) The exploration and use of outer space, including the moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind.
2) Outer space, including the moon and other celestial bodies, shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies.
3) There shall be freedom of scientific investigation in outer space, including the moon and other celestial bodies, and States shall facilitate and encourage international co-operation in such investigation.

Space belongs to all humankind, not to any single government or country and is not the province of some petulant billionaire with an overactive imagination, ostensibly to provide broadband service to underserved regions of the globe.

Aside from existing observatories and installations with their networks of astronomers, researchers and scientists, new observatories are slated to come online over the next decade; the Large Synoptic Survey Telescope (LSST) is scheduled to go online in late 2022, the Thirty Meter Telescope (TMT) on Mauna Kea in Hawaii is scheduled for the mid 2020s, the Giant Magellan Telescope (GMT) for mid 2025 and the ESO’s Extremely Large Telescope (EELT), also scheduled for the mid-2025 time frame.

I encourage all members of this space to have a read of the policy positions of the AAS, the IAU, the IDA and the National Radio Astronomy Observatory (NRAO). In addition to altering the visual and aesthetic character of the night sky, the proposed frequency bands Starlink would employ have potential impacts to radio astronomy, to the future detriment of such worldwide collaborative projects as the recent imaging of a Black Hole’s Event Horizon 55 million light years away!

No, SpaceX doesn't have to modify the skins of new satellites and be permitted to continue on this reckless path; they have to deorbit the existing 60 already in orbit with the remainder of the project to be put on indefinite hold until a full global impact study can be conducted. It cannot be allowed to proceed until guarantees can be provided from SpaceX that they have an acceptable remedy that will protect the near-earth environment and the night sky, or if ever.

Please contact your elected representatives and, especially, the Federal Communications Commission (FCC). When you contact them, directly address your comments to Ajit Pai, the FCC Commissioner as he was the individual who gave the green light to this disaster.

That this project was allowed to proceed as far as it did is unacceptable.

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James Daly, Ph.D

June 24, 2019 at 9:22 am

As an addendum to my comments:
Article I, point 1 of the 1967 treaty is quite clear regarding the use of space as it shall be the province of all mankind. The image from Lowell Observatory clearly illustrates that the launch of Starlink’s first 60 satellites is in breach of points 2 and 3.

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