Submitted by mysoxrstinky t3_zdmyo8 in askscience
I have been hearing a lot of criticism of Elon's sky net based on the light pollution it will cause and the impact this will have on astronomy. Is there any concern satellite launches will impact other bands of radio waves?
Light pollution isn't the right term. The issue with Starlink, and all satellites, is that they reflect sunlight and for visual astronomers and the pros working in the visible spectrum, those streaks of light cause issues with obsevations. Yes, software can deal with some of it, maybe, and astronomers can anticipate some satellite passes, but it's the volume of new satellites that are problematic.
The concern, and I don't know how valid this concern is, with all of these satellite internet companies is they are broadcasting back to earth and that could interfere with radio astronomy due to leakage out of band and harmonics.
I do know that the VLA - Very Large Array radio telescope has an elecroinic device usage policy - https://public.nrao.edu/visit/very-large-array/dos-and-donts/#rfi-section - and hours where traffic is not allowed on roads nearby becaue the equipment is easily sensitive enough to pick up the sparks from the very radio noisy spark plugs on the engine and nowadays all the other radio/cell/electronic gear on a car, causing noise in the observations and as I was told a lot of extra annoying data cleanup and longer observing times that they otherwise don't have to do. The VLA is very impressive and worth a visit by the way. Beautiful and ominous.
Yes, it’s called radio frequency interference (RFI) and causes a lot of issues; especially when dealing with radio interferometry where radio loud noise sources can cause contamination in adjacent frequencies/bands. An example of existing loud sources in radio specifically low frequency is the ORBCOMM system of satellites, which causes trouble for detection in early universe studies.
Yes, radio telescopes can suffer from pollution in the same way that conventional telescopes do. Pollution, such as light pollution from nearby cities and atmospheric pollution from industrial activities, can interfere with the ability of radio telescopes to collect and interpret signals from space.
However, radio telescopes have some advantages over conventional telescopes when it comes to pollution. For one, radio waves are less affected by atmospheric pollution than visible light, so radio telescopes can still operate effectively in areas with high levels of atmospheric pollution.
Additionally, radio telescopes can be located in remote areas, away from sources of light and atmospheric pollution. This allows them to operate with less interference and provide more accurate observations of the universe.
Overall, while radio telescopes are not immune to pollution, they can still provide valuable insights into the universe despite the presence of pollution.
Starlink is unavailable in various regions around larger radio telescopes (including the VLA) to minimize interference with observations. I made a list of all these holes. 20 of them are associated with radio telescopes, 2 of them we didn't figure out (1 is at the NSA headquarters, but we don't know if that's the reason).
I'd say it's fine to use the term "light pollution" to refer to any unwanted anthropogenic photons hitting your detector, whether ambient or point sources.
One of the funniest (but probably really frustrating to figure out) "radio pollution" cases is the story of strange radio spikes that plagued an observatory for years being caused by misuse of a microwave oven…
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When Penzias and Wilson at bell Labs discovered the CMB (cosmic microwave background) they were actually working to rule out nearby microwave interference/pollution.
[deleted] t1_iz2u64h wrote
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