The last generation of stargazers

[Ags]

The idea of orbiting solar power stations is gaining more and more traction.

UK innovators get £4.3m to develop space-based solar power | Solar power | The Guardian

In a couple of decades there might be dozens or even hundreds of these in orbit. I imagine each one would be as bright as the Moon. The destruction of the night-time environment, with all of the associated health and environmental damage, would be complete.

At least we wouldn't need streetlights any more.

The ISS is very roughly 60 m x 90 m, while orbital solar stations could have surface areas around 10 square km. That is about 1000 times bigger, so about 8.5 magnitudes brighter. The ISS is mag -3, these would be edging towards mag -12, roughly equivalent to a full Moon.

Edited June 13, 2023 by Ags

[ONIKKINEN]

Seems like a good idea, only a matter of time this happens anyway. The Sun is a limitless well of green energy just waiting to be tapped into properly and space based power makes the most sense here.

And how about when these power stations are on the night side of Earth when astronomers are out and about? Not going to be bright, while being a bit of a nuisance obstructing light from behind them this is far from the end of the world for astronomers. Would make little sense to put these in a high orbit since beaming power from greater distances means more is lost along the way. This article does not mention the orbits these would go into, but i think a Sun synchronous orbit makes the most sense (always in sunlight). Sun synchronous orbit also means these will quite literally never be visible at night to ruin someones stargazing. If these are put to higher orbits, they will be dimmer in the night sky.

I am always very disappointed when i see one of these threads claiming the end is nigh. Its not, and these developments (inlcuding starlink) are overwhelmingly good for almost everyone on Earth.

[Sunshine]

Not going to happen anytime soon, I wouldn’t worry, 90 percent of grand technological endeavors fizzle out when the real costs and challenges come to light.

[Ags]

6 hours ago, ONIKKINEN said:

This article does not mention the orbits these would go into, but i think a Sun synchronous orbit makes the most sense (always in sunlight).

I am not anti-progress in general but remember these have to beam the energy down to earth. That means the station has to be well above the horizon at night and of course in full sun. Unless we start laying superconducting power lines, the receiver stations have to be relatively local, so if UK is receiving energy, then the power stations have to be in the UK's night sky.

It's doubtful that the orbit would be as low as the ISS (to much atmospheric drag and space junk) so if we assume an orbit ten times higher, then I think the power station would be maybe 100 times fainter - still around magnitude -6, so it would cast quite visible shadows and definitely ruin night vision. I don't think a higher orbit is a technical problem actually as the receiver stations would themselves be enormous covering many square kilometers.

I used to be a fan of orbital power, and still would be if I could be assured that the night environment would not be (further) ruined. As astronomers we can adapt to these changes of course - Solar, lunar and planetary observing would be unaffected at least, but the birds and insects cannot adapt, at least not in the short term.

Edited June 14, 2023 by Ags

[Paz]

On a similar note I think we are the last generation of natural moon observers. Once the first visible artificial establishments go up on the moon those of us who saw it before will become a silent memory soon enough.

[saac]

1 hour ago, Paz said:

On a similar note I think we are the last generation of natural moon observers. Once the first visible artificial establishments go up on the moon those of us who saw it before will become a silent memory soon enough.

And tonight's target is the lunar Coca Cola advertising sign in Mare Imbrium, tomorrow night we will go after the golden arches of McDonalds south of Copernicus crater.  Give me strength, time to pull the black and yellow stripped handle. 

Jim 

[Mr Spock]

The Last Stargazer - sounds like a movie title 

[Nik271]

Don't worry, it won't happen anytime soon, the technological challenges are huge. 

Solar energy orbital stations have been talked about ever since the 1970s (in science fiction even earlier!) and did not happen for the same reason they won't happen now: cost of putting things into orbit, and transmission problems. Unless we have a magic space elevator it will always be cheaper and safer to generate solar energy on the ground. 

 

[Ratlet]

I'm sure SIM City 2000 had something to say about the potential pitfalls of space based energy transmission.

[Mr Spock]

Did nobody watch Dr Who The Sunmakers? 

[Paul M]

Seems to me someone is hoping to lap up some government money by using buzz words.

I can see them getting the money but not delivering anything at all.

And anyway, the shadows of all those orbiting solar panels will cause global cooling.

I've always said that the only thing worse than global warming is global cooling. Ain't nobody gonna vote for that!🤣

[The Lazy Astronomer]

Given that we've known about the environmental damages of fossil fuels for some considerable time, and as a collective group, we've made really very little progress in moving to other ways to produce our energy with terrestrial technology (for a multitude of reasons), I'm not going to be too worried about this. If it happens within the next 200 years, please feel free to reanimate my corpse and I'll happily eat my hat. 

[Mandy D]

2 hours ago, Paul M said:

And anyway, the shadows of all those orbiting solar panels will cause global cooling.

I've always said that the only thing worse than global warming is global cooling. Ain't nobody gonna vote for that!🤣

Shadows? Global cooling? You are beaming energy (heat) down to Earth that was not destined for our planet, so that is going to increase energy and heat the planet. If these panels are producing shadows on the Earth, we are wasting our time, are we not? Or am I missing something obvious, here?

I totally agree that global cooling is the last thing we want or need. Unfortunately, the world is stuck with the idea that warming is entirely a bad thing. Is another ice age what we want? Clive Best has a chart on his website somewhere that lists the levels between Snowball Earth and Fireball Earth. We are just one step up from Snowball Earth at present.

[ONIKKINEN]

3 hours ago, Paul M said:

Seems to me someone is hoping to lap up some government money by using buzz words.

I can see them getting the money but not delivering anything at all.

And anyway, the shadows of all those orbiting solar panels will cause global cooling.

I've always said that the only thing worse than global warming is global cooling. Ain't nobody gonna vote for that!🤣

Global cooling seems like the least of our worries for the climate and Earth in general. Even if we reversed our direction of greenhouse gas generation and went too far any kind of glaciation event will be seen centuries in advance. Easy to pump the greenhouse gases back into the atmosphere in that case.

Whereas global warming is not centuries away, its right now and everywhere.

But i do agree 4 million is an afternoon project and a 1 square meter unfolding prototype on a rideshared falcon 9 with an orbital lifespan of 2 weeks. 4 trillion would maybe start the project going properly. Probably not something that will see any real results in the following few decades at least.

Edited June 15, 2023 by ONIKKINEN

[Paul M]

13 minutes ago, Mandy D said:

Shadows? Global cooling? You are beaming energy (heat) down to Earth that was not destined for our planet, so that is going to increase energy and heat the planet. If these panels are producing shadows on the Earth, we are wasting our time, are we not? Or am I missing something obvious, here?

The greenhouse effect is all about atmospheric gasses trapping thermal infrared that would have otherwise radiated to space. Or at least the upset in the solar energy budget caused by increased concentrations of greenhouse gases.

I'm not expecting the energy being beamed down to earth will warm the atmosphere significantly along its path, else efficiency is a bit pants!

So, yeah, shadows, innit!

[Paul M]

Earth has always had a climate that is either cooling or warming. The cold periods seem to have been worse for life than the warm periods.

I'd be careful of assuming that he (or she, or they) that control greenhouses gases also control climate!

There is a positive feedback in atmospheric CO2, where by warmer oceans are less effective sinks of Co2, more warming, less co2 sinks in the oceans... The reverse is also true. Make sure you don't strip too much CO2 out of the atmosphere. Although that is unlikely. Even if our self flagellation sends us back to the dark ages, China et al will ensure atmospheric CO2 continues to rise  

[Mandy D]

10 minutes ago, Paul M said:

The greenhouse effect is all about atmospheric gasses trapping thermal infrared that would have otherwise radiated to space. Or at least the upset in the solar energy budget caused by increased concentrations of greenhouse gases.

I'm not expecting the energy being beamed down to earth will warm the atmosphere significantly along its path, else efficiency is a bit pants!

So, yeah, shadows, innit!

OK, so if there no losses directly to the atmosphere along the beam path, that means all the energy is being collected by the receiving station. What happens to that energy then? Do we simply transport it back to space? In which case the efficiency is worse than "a bit pants". Energy is energy. Once it is here it is effectively heating the planet and atmosphere or it is escaping back into space. Which is it?

I'm not sure we are ever going to see shadows from such collection stations as they would be so positioned to avoid this problem, otherwise, what is the point? We may as well let the energy just hit the Earth directly from the Sun.

[Paul M]

Just now, Mandy D said:

OK, so if there no losses directly to the atmosphere along the beam path, that means all the energy is being collected by the receiving station. What happens to that energy then? Do we simply transport it back to space? In which case the efficiency is worse than "a bit pants". Energy is energy. Once it is here it is effectively heating the planet and atmosphere or it is escaping back into space. Which is it?

I'm confused.

The energy is supposed to replace fossil fuels and supplement "renewables" (I struggle to use that phrase even in quotes). It would be hoped that the energy gets used wherever it's needed and although it all eventually becomes heat, it's not adding to global warming in the same way that green house gases do.

Global warming is caused by solar energy being trapped in the atmosphere (via a few absorption and reemissions). It's a direct warming of the atmosphere caused by the Sun, not a thermal residual of energy (green or otherwise) expended in our everyday, technological lives.

It's not the heat of your coal fire that is the problem it's the gases it emits that are the problem.

Allegedly 🙈🙊🙉 

[Mr Spock]

If this topic shifts anymore towards global warming it will close pretty quickly 

[Paul M]

1 hour ago, Mandy D said:

We may as well let the energy just hit the Earth directly from the Sun.

Indeed, but turning that into usable,  preferably electrical energy, still requires solar panels. Here on the surface such panels are subject to seasons, weather and darkness. As you say, we'd hope orbiting arrays would avoid all 3 of those.

An interesting news snippet doing the rounds here in the UK is that a coal fired power station has been put back online due to the current excessive UK heat.

Apparently the average solar panel is designed with a panel operating temperature of 21 degrees. Efficiency drops off with increased temperature. So ours in the UK are feeling the heat just now.

It's assumed that an orbiting array would be designed for continuous and efficient operation at the steady temperature it experiences. After all solar panels in space aren't new technology.

So certainly a great idea but transmitting the energy efficiently and converting it to a usable form are the terminal sticking points?

[Zermelo]

https://www.bbc.co.uk/news/science-environment-65907342