<p>It would have to be a hell of a big disc, and in a geostationary orbit. No, it's not practical, we can never control the weather with satellites in space. It's a non-starter. What might be done with satellites is to reflect the sun's rays into frostbound valleys where there is a small town in shadow which is not getting the benefits of spring as early as other nearby towns. It could also be used for night time street lighting. However, I doubt whether the results would justify the expense, and there are bound to be people who wouldn't like it. The things you mention in your question are not possible.</p>

CC BY-SA 4.0
2020-01-10T16:43:26.277Z
I agree a satellite in geostationary orbit would need to be HUGE, but one at the largrange point could be much smaller.
Martin
CC BY-SA 4.0
2020-01-10T15:45:48.830Z
2020-01-10T15:45:48.830Z
Michael Walsby
<p>There is recorded evidence from solar eclipses that the <a href="https://www.nationalgeographic.com/news/2012/3/120328-solar-eclipses-winds-weather-sun-earth-space-science/" rel="nofollow noreferrer">moon's shadow has a detectable weather effect</a>.</p>

<p>If we placed a disk in space we could project a cold spot onto the planet and control it's position using the position of the spacecraft. In simple terms warm air moves towards cold, so that could be used to pull weather systems out of their normal track.</p>

<ol>
<li>What is the smallest disk that would create a 300km shadow

<ul>
<li>Where would be the best place to put it between the earth and sun</li>
</ul></li>
<li>What size of effect would you have?

<ul>
<li>Could you move a monsoon from flooded Asia to drought Australia</li>
<li>How big would the shadow need to be to have an appreciable effect?</li>
</ul></li>
<li>If it was always "on" (i.e. you could turn it "off" by rotating it on edge), would the cooling effect be significant?</li>
</ol>

<p>It's not going to stop global warming but it might buy some time and help redistribute the water more evenly.</p>

CC BY-SA 4.0
2020-01-10T15:36:16.027Z
Wouldn't the lagrangian point "hold" the disk in place?
Martin
CC BY-SA 4.0
2020-01-10T15:37:22.007Z
Simpsons already did it!
Jean-Marie Prival
CC BY-SA 4.0
2020-01-10T19:55:56.563Z
we have had this question in different flavors many times in the past,baloons-satelites-injecting material into the atmosphere and now the disc,the only thing left is somebody suggesting a cut in CO2.
trond hansen
<climate-change><weather-satellites>
Could we control the weather with a disk in space?
Martin
# Could we control the weather with a disk in space?

(Asked by: username_0 on 2020-01-10)

There is recorded evidence from solar eclipses that the [moon's shadow has a detectable weather effect](https://www.nationalgeographic.com/news/2012/3/120328-solar-eclipses-winds-weather-sun-earth-space-science/).

If we placed a disk in space we could project a cold spot onto the planet and control it's position using the position of the spacecraft. In simple terms warm air moves towards cold, so that could be used to pull weather systems out of their normal track.

1. What is the smallest disk that would create a 300km shadow
   * Where would be the best place to put it between the earth and sun
2. What size of effect would you have?
   * Could you move a monsoon from flooded Asia to drought Australia
   * How big would the shadow need to be to have an appreciable effect?
3. If it was always "on" (i.e. you could turn it "off" by rotating it on edge), would the cooling effect be significant?

It's not going to stop global warming but it might buy some time and help redistribute the water more evenly.

**Tags:** climate-change, weather-satellites

> **Comments:**
> **username_0**: Wouldn't the lagrangian point "hold" the disk in place?  
> **username_1**: Simpsons already did it!  
> **username_2**: we have had this question in different flavors many times in the past,baloons-satelites-injecting material into the atmosphere and now the disc,the only thing left is somebody suggesting a cut in CO2.  

---

## 1 answers

### Answer by username_3 on 2020-01-10. Score: 0

It would have to be a hell of a big disc, and in a geostationary orbit. No, it's not practical, we can never control the weather with satellites in space. It's a non-starter. What might be done with satellites is to reflect the sun's rays into frostbound valleys where there is a small town in shadow which is not getting the benefits of spring as early as other nearby towns. It could also be used for night time street lighting. However, I doubt whether the results would justify the expense, and there are bound to be people who wouldn't like it. The things you mention in your question are not possible.

> **Comments:**
> **username_0**: I agree a satellite in geostationary orbit would need to be HUGE, but one at the largrange point could be much smaller.  

---

