SpaceX's Starlink satellites are interfering with ground-based astronomy

Shawn Knight

Posts: 14,059   +153
Staff member
In brief: SpaceX on Tuesday sent another batch of Starlink satellites to low Earth orbit, pushing the total number of units circling the globe to nearly 1,900. While that’s great news for SpaceX and Starlink customers, it has become a bit of a problem for astronomers here on Earth.

Ground-based observations often involve long exposures to capture light from distant targets. While small, Starlink’s satellites can still reflect enough sunlight to interfere with astronomers’ images, showing up as streaks of light in photos.

To quantify the satellites’ impact, a group of researchers analyzed observations collected between November 2019 and September 2021 from the Zwicky Transient Facility (ZTF) at the Palomar Observatory in California.

The team found 5,301 streaks from Starlink satellites. Twilight observations were impacted the most, with streaked image frequency increasing as more satellites were put into space. In late 2019, less than 0.5 percent of images were affected by the satellites. By August 2021, nearly one in five images featured unwanted satellite streaks.

Worse yet, the team estimates that by the time the constellation of Starlink satellites reaches 10,000 units, all ZTF images captured at night could be affected.

As it stands today, however, science operations from the ZTF aren’t strongly affected by the satellites. And really, it may not become a huge issue in the future, either.

SpaceX in 2020 started adding visors to help block sunlight from reaching the satellites, effectively reducing satellite brightness by a factor of five. Furthermore, one of the study’s co-authors said software could be developed to help mitigate the problem on multiple fronts. For example, astronomers could use software that tracks satellites’ location to avoid scheduling an observation when one might be in view.

The team’s full write-up can be found in the January 14 issue of The Astrophysical Journal Letters.

Permalink to story.

 

wiyosaya

Posts: 7,520   +6,349
That's a bummer. What has ground based photography contributed as of late? Valid question not an indictment
Many of the newer, ground-based telescopes are able to produce images that are better than the Hubble Space Telescope - for instance - https://keckobservatory.org/ Look at their news page for some of their recent contributions.

And here's another - https://www.gemini.edu/ They also have a news page.

When this comes on-line, it will easily produce images better than Hubble, and perhaps even better than JWST - https://www.eso.org/sci/facilities/eelt/

Ground based astronomy is still a big thing.

And speaking as someone with experience in Amateur Astrophotography, having to schedule observations around when there will be a Starlink satellite in the sky is quite an inconvenience.

18% of images being streaked by Musky's satellites is not a small figure.

So is the future that in order to do great astronomy, you have to use a telescope in space?

Edit - this is from 2019, but emphasizes the point, IMO. https://skyandtelescope.org/astronomy-news/starlink-satellites-astronomy/
 

Underdog

Posts: 255   +154
Hey guys, lighten up. What's the loss of uncluttered terrestrial based astronomy against the profit Musk will get offering fast internet access at $99 a month to people living out in the sticks with no fiber? He needs the money.
 
The solution is simple. move the scopes and camera to the stars. with Low orbit sats. becoming a common issue with many more on the way from more than just Starlink the issues will keep compounding. Its not going to stop regardless of what a few would like. With rockets today able to go up and down weekly now is the time to push to the stars to put the scopes and camera beyond the LOS. this only only solves the issue but should offer better clarity than you can get from the planets atmosphere with out requiring special processing to make the pictures that we see today. you would not have the direct light pollution issues which requires special filtering or exposures to get a better picture. As to hubble the reason its not that great is it was built in the 90's where todays cameras and optics are light years ahead. If we put todays sensors in space ... need I say more :)
 

DaveBG

Posts: 619   +284
Hey guys, lighten up. What's the loss of uncluttered terrestrial based astronomy against the profit Musk will get offering fast internet access at $99 a month to people living out in the sticks with no fiber? He needs the money.
So at what price would you sell satellite based internet then? Just curious what would you price it at and your math behind it.
Also OneWeb recently launched another batch of their satellites for a competing network. No one said anything. Its only Sarlink satellites that destroy ground based observatories right?
 

psycros

Posts: 4,085   +5,626
Literally every astronomy organization raised the alarm about this before the first Starlink birds were launched. They were ignored, of course, just like all the scientists who've warned about the proliferation of space junk which will soon make orbital ventures incredibly risky. That's not even counting actions by irresponsible regimes like China and Russia that happily blow up satellites in their pursuit of relentless militarism. There's a solution, of course, and I've no doubt that Elon and those like him are conveniently already working on it: rockets that launch microsats which fly out and latch on to orbital debris and then steer it into Earth's atmosphere.
 

Austinturner

Posts: 351   +452
I really don’t think that this is an important enough concern that it should stop all the technological progress that can come from satellites. Completely agree with de-orbiting old satellites and not blowing them up and creating space junk though.
 

Austinturner

Posts: 351   +452
Literally every astronomy organization raised the alarm about this before the first Starlink birds were launched. They were ignored, of course, just like all the scientists who've warned about the proliferation of space junk which will soon make orbital ventures incredibly risky. That's not even counting actions by irresponsible regimes like China and Russia that happily blow up satellites in their pursuit of relentless militarism. There's a solution, of course, and I've no doubt that Elon and those like him are conveniently already working on it: rockets that launch microsats which fly out and latch on to orbital debris and then steer it into Earth's atmosphere.
The US also created space junk by shooting one of its own satellites in 2008. Its bad whoever is doing it and making a mess.
 

yRaz

Posts: 4,352   +5,004
So did I, long before a**hole Musk ever launched the first one,
As someone who is into astrophotography, this has me at a loss for words. I wanted to build a "sky shed" so I didn't have to setup my telescope everytime I wanted to use it, but what's the point? And we have massive ground based telescopes, an 80% reduction in reflectivity is nothing for a 10 meter telescope. Not to mention the ones already in the sky screwing up 1/5th of the exposures.
 

captaincranky

Posts: 18,561   +7,413
@yRaz Try to think of all the "poor people" Musk is going "to help" with his $500.00 base stations and $100.00 a month satellite internet. :rolleyes:

He really is an avaricious, psychotic, piece of sh!t. I honesty can't fathom why I get so much blow back from his groupies here when I mention it.
 
Last edited:

Mr Majestyk

Posts: 1,156   +1,050
Astronomers were up in arms when they first heard of the proposal and it's disgusting it was ever allowed to proceed. This is so infuriating.
 

wiyosaya

Posts: 7,520   +6,349
The solution is simple. move the scopes and camera to the stars. with Low orbit sats. becoming a common issue with many more on the way from more than just Starlink the issues will keep compounding. Its not going to stop regardless of what a few would like. With rockets today able to go up and down weekly now is the time to push to the stars to put the scopes and camera beyond the LOS. this only only solves the issue but should offer better clarity than you can get from the planets atmosphere with out requiring special processing to make the pictures that we see today. you would not have the direct light pollution issues which requires special filtering or exposures to get a better picture. As to hubble the reason its not that great is it was built in the 90's where todays cameras and optics are light years ahead. If we put todays sensors in space ... need I say more :)
Ground base scopes are cheaper. At 1.15Bn euros, they could have built 10 of these babies for the price of one JWST - https://www.eso.org/sci/facilities/eelt/
As someone who is into astrophotography, this has me at a loss for words. I wanted to build a "sky shed" so I didn't have to setup my telescope everytime I wanted to use it, but what's the point? And we have massive ground based telescopes, an 80% reduction in reflectivity is nothing for a 10 meter telescope. Not to mention the ones already in the sky screwing up 1/5th of the exposures.
The Sky&Telescope link I posted gives a good idea of the problems. It does not sound like it would be easy, even for professional observatories, to omit streaked frames.
Hey guys, lighten up. What's the loss of uncluttered terrestrial based astronomy against the profit Musk will get offering fast internet access at $99 a month to people living out in the sticks with no fiber? He needs the money.
In his little mind, anyway.
@yRaz Try to think of all the "poor people" Musk is going "to help" with his $500.00 base stations and $100.00 a month satellite internet. :rolleyes:

He really is a psychotic piece of sh!t. I honesty can't fathom why I get so much blow back from his groupies here when I mention it.
You'll never get an argument from me on that, Captain.
 

wiyosaya

Posts: 7,520   +6,349
So at what price would you sell satellite based internet then? Just curious what would you price it at and your math behind it.
Also OneWeb recently launched another batch of their satellites for a competing network. No one said anything. Its only Sarlink satellites that destroy ground based observatories right?
OneWeb is talked about in the Sky & Telescope article I linked in my previous post. Perhaps one reason they are not pounded like Musky and Starlink is that their satellites are in a higher orbit meaning that they do not shine as brightly as Musky's satellites do. This is mentioned in the S & T article I linked.

Also, Musky's "solution" of painting his satellites black will not work for ground-based infrared astronomy. Painting them black will probably make it worse for ground-based infrared astronomy.
@yRaz Try to think of all the "poor people" Musk is going "to help" with his $500.00 base stations and $100.00 a month satellite internet. :rolleyes:

He really is a psychotic piece of sh!t. I honesty can't fathom why I get so much blow back from his groupies here when I mention it.
Yeah, maybe he can sell them in Rural India, after all, Bill Gates thought he could sell them a $10M plus sewage treatment plant that needed millions more for infrastructure. :rolleyes:
I've done my bit by signing up to Starlink twice :p
I've got 500Mbps symmetric FTTH. :p
 

Underdog

Posts: 255   +154
My view of the sunset includes power poles and lines. Damned electricity!!!
They are only a problem where the distribution companies chose the cheapest option. Power lines can and are being buried underground in other places on the planet. Imagine if all your wonderful fibre internet cabling was up on poles. Pretty soon people wouldn't be able to see anything above 30 feet or so.