CR4® - The Engineer's Place for News and Discussion®


Previous in Forum: The Beginning of the End of Tesla   Next in Forum: Atlas V Launch Success
Close
Close
Close
42 comments
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9

Solar Eclipse

08/16/2017 4:08 PM

Just curious, How large would something need to be when in a geosynchronous orbit, to also have the aprox 1/2 a degree diameter so periodically, artificial solar eclipses could be made?

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#1

Re: Solar Eclipse

08/16/2017 4:35 PM
__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19977
Good Answers: 749
#2

Re: Solar Eclipse

08/16/2017 4:38 PM

∼192 miles.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9
#3
In reply to #2

Re: Solar Eclipse

08/16/2017 4:57 PM

a tad too big he he he

Register to Reply
Guru
Hobbies - Musician - Engineering Fields - Chemical Engineering - New Member Engineering Fields - Control Engineering - New Member Engineering Fields - Instrumentation Engineering - New Member

Join Date: Jan 2007
Location: Moses Lake, WA, USA, Thulcandra - The Silent Planet (C.S. Lewis)
Posts: 3929
Good Answers: 174
#4
In reply to #3

Re: Solar Eclipse

08/16/2017 5:33 PM

Hey, it's only a little over twice the diameter of the first Death Star.

__________________
"Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone." - Ayn Rand
Register to Reply
Guru
Engineering Fields - Electrical Engineering - New Member Fans of Old Computers - Commodore 64 - New Member Popular Science - Evolution - New Member United States - Member - New Member

Join Date: Oct 2013
Location: Illinois, 7 county region (The 'blue dot' that drags the rest of the 'red state' around during presidential elections.)
Posts: 3488
Good Answers: 87
#35
In reply to #4

Re: Solar Eclipse

08/18/2017 3:53 PM

But it doesn't need to be a sphere, if its pitch and roll can be controlled while in orbit. We can make it a flat(ish) disk.

And we already know how to do that, since it's the same concept that keeps the solar panels on the satellites aimed for maximum energy collection.

__________________
( The opinions espressed in this post may not reflect the true opinions of the poster, and may not reflect commonly accepted versions of reality. ) (If you are wondering: yes, I DO hope to live to be as old as my jokes.)
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13438
Good Answers: 152
#36
In reply to #35

Re: Solar Eclipse

08/18/2017 4:44 PM

Why not just build a gallomping big area worth of white plastic covered green houses, and save all that rocket fuel, save astronaut extra-vehicular labor, and save us all from the thing when it comes crashing back through the atmosphere. The whole thing that many apparently do not get, we already have far too much junk in space.

This is not the time to start loading up orbit(s) with even more stuff, unless you use this disk to act like fly paper for space junk, and clean up orbital space around our planet. Our environmental responsibility does not end with the atmosphere, really, now does it?

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru
Engineering Fields - Electrical Engineering - New Member Fans of Old Computers - Commodore 64 - New Member Popular Science - Evolution - New Member United States - Member - New Member

Join Date: Oct 2013
Location: Illinois, 7 county region (The 'blue dot' that drags the rest of the 'red state' around during presidential elections.)
Posts: 3488
Good Answers: 87
#41
In reply to #36

Re: Solar Eclipse

08/21/2017 9:40 AM

"unless you use this disk to act like fly paper for space junk, and clean up orbital space around our planet."

I have been working on that problem, but I've hit a snag how to keep the gigantic wads of chewed bubblegum soft and sticky while in space, so it can catch the space debris into a big ball of junk that can be deorbited to burn up in the atmosphere or splash into the ocean.

__________________
( The opinions espressed in this post may not reflect the true opinions of the poster, and may not reflect commonly accepted versions of reality. ) (If you are wondering: yes, I DO hope to live to be as old as my jokes.)
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13438
Good Answers: 152
#42
In reply to #41

Re: Solar Eclipse

08/21/2017 10:23 AM

Perhaps a better way would be to use a laser to slow the space junk down, and let it fall into the atmosphere for immediate "recycling".

I am just saying perhaps. Not definitely. OK?

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#6
In reply to #3

Re: Solar Eclipse

08/16/2017 7:17 PM

Maybe we could catch an asteroid that size.....

Vesta is ~330 miles in diameter...

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Engineering Fields - Mechanical Engineering - New Member Fans of Old Computers - TRS-80 - New Member Popular Science - Weaponology - New Member Safety - Hazmat - New Member Hobbies - Fishing - New Member United States - Member - New Member

Join Date: Apr 2012
Location: Detroit MI, USA
Posts: 2084
Good Answers: 209
#5

Re: Solar Eclipse

08/16/2017 5:50 PM

500 to 1000 megatons should throw up enough dust and debris to make it appear we are having an artificial eclipse for several decades. We as a species (no politics included) seem to be headed that way.

__________________
How we deal with death is at least as important as how we deal with life. --CAPTAIN KIRK, Star Trek II: The Wrath of Khan
Register to Reply
2
Guru

Join Date: Apr 2008
Location: Chicago
Posts: 2190
Good Answers: 70
#7
In reply to #5

Re: Solar Eclipse

08/16/2017 8:41 PM

And I think the internet is a driving force.

Too many people are taking too many other people's tantrum personally and responding with a tantrum like a never ending game of idiots ping-pong.

__________________
High Tolerance is Beautiful
Register to Reply Good Answer (Score 2)
Guru
Engineering Fields - Optical Engineering - Member Engineering Fields - Engineering Physics - Member Engineering Fields - Systems Engineering - Member

Join Date: Apr 2010
Location: Trantor
Posts: 5198
Good Answers: 620
#8

Re: Solar Eclipse

08/16/2017 9:05 PM

It would be better in a near-polar orbit, around 120 miles up. The sphere would only need to be 1 mile in diameter, and as it orbits while the Earth spins underneath it, eventually over the course of a few weeks every inhabited place on Earth will see at least one brief solar eclipse.

A higher orbit would require a larger sphere, but the angular speed would be slower and the eclipses longer.

__________________
Whiskey, women -- and astrophysics. Because sometimes a problem can't be solved with just whiskey and women.
Register to Reply Score 1 for Good Answer
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#9
In reply to #8

Re: Solar Eclipse

08/16/2017 9:48 PM

Couldn't we just make clouds?

No not those kind of clouds....

These kind

Jules Verne would be proud....

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Engineering Fields - Optical Engineering - Member Engineering Fields - Engineering Physics - Member Engineering Fields - Systems Engineering - Member

Join Date: Apr 2010
Location: Trantor
Posts: 5198
Good Answers: 620
#10
In reply to #9

Re: Solar Eclipse

08/16/2017 10:17 PM

I want a device to remove clouds, not make more. If I want more clouds I can take my car in to the car wash.

__________________
Whiskey, women -- and astrophysics. Because sometimes a problem can't be solved with just whiskey and women.
Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#11
In reply to #10

Re: Solar Eclipse

08/16/2017 10:50 PM

So you're saying we need more car washes?

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Engineering Fields - Optical Engineering - Member Engineering Fields - Engineering Physics - Member Engineering Fields - Systems Engineering - Member

Join Date: Apr 2010
Location: Trantor
Posts: 5198
Good Answers: 620
#23
In reply to #11

Re: Solar Eclipse

08/17/2017 6:38 PM

Nice Moons.

__________________
Whiskey, women -- and astrophysics. Because sometimes a problem can't be solved with just whiskey and women.
Register to Reply
Guru

Join Date: Apr 2010
Posts: 5740
Good Answers: 575
#14
In reply to #8

Re: Solar Eclipse

08/17/2017 9:51 AM

Or a dime at arm's length...

Register to Reply
Guru

Join Date: Apr 2011
Posts: 6542
Good Answers: 241
#12

Re: Solar Eclipse

08/16/2017 11:41 PM

At 1/2°, one unit in diameter is almost 115 units away.

A shade in low Earth orbit would probably be far less daunting a task than a shade at geosynchronous orbit or at L1.

At a fairly low, LEO a shade might be on the order of a mile in diameter for 1/2°...so less than a square miles of shade material.

At geosynchronous orbit, a shade would be on the order of 200 miles in diameter to be 1/2°....so upwards of 30,000 square miles of shade material.

At Lagrange 1, a shade would be more than 800,000 miles in diameter for 1/2°...so more than 480,000,000,000 square miles of shade material.

.

...or somewhere thereabouts.

.

If you were willing to settle for a high altitude balloon, for 1/2° the diameter could be around 1000 feet. If the balloon were spherical, it would have a surface area a little over 3 million square feet.

.

You could also have a drone fly a disk less than a foot wide 50 feet over your head between you and the sun.

Or you could use a parasol.

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#13
In reply to #12

Re: Solar Eclipse

08/17/2017 1:41 AM
__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9
#15

Re: Solar Eclipse

08/17/2017 11:23 AM

Just so everyone knows,

Any "Shade" or obscuring idea that is not above the atmosphere, just doesn't work very well if at all. Because of the sky remaining bright because it is still getting all the sunlight. So the faint corona is still not visible.

Register to Reply
Guru

Join Date: Apr 2011
Posts: 6542
Good Answers: 241
#16
In reply to #15

Re: Solar Eclipse

08/17/2017 11:38 AM

Just so you know,

That is a picture from orbit of the bright reflection of the sun off the Mediterranean. That is a less than optimal reflector at sea level doing a pretty good job of reflecting a lot of energy back out into space.

Better reflector at higher altitudes will perform even better. So light can be reflected back into space. No need to be concerned that it might not work 'at all.

Whether or not it works well depends on a lot of factors, including the particular criteria for well.

....just so you know.

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9
#17
In reply to #16

Re: Solar Eclipse

08/17/2017 12:04 PM

It's not so much as "Reflecting" the Suns light, But More of a "Blocking" of it.

The Moon is a Terrible reflector. Only about 3% of the light that hits it is actually reflected.

Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#18
In reply to #17

Re: Solar Eclipse

08/17/2017 3:28 PM

..."About 29 percent of the solar energy that arrives at the top of the atmosphere is reflected back to space by clouds, atmospheric particles, or bright ground surfaces like sea ice and snow."...

https://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9
#19
In reply to #18

Re: Solar Eclipse

08/17/2017 5:16 PM

I'm not gonna get into how a solar eclipse happens with you. Since you have your mind set that is has something to do with reflectivity, when reflectivity has zero effect on what is happening during an eclipse.

I have been into Astronomy since 1965, and have taught it even at collegiate levels since 1975, and try to maybe Google it or something. But reflectivity has absolutely ZERO effect on what is happening during a total solar eclipse.

Register to Reply Score 1 for Off Topic
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#20
In reply to #19

Re: Solar Eclipse

08/17/2017 5:53 PM

Solar eclipse? I thought we were talking about global warming.... Why else would you want to see solar eclipses all the time? Seen one you've seen them all...

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9
#21
In reply to #20

Re: Solar Eclipse

08/17/2017 5:56 PM

Obviously you have never seen one in person.

Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#22
In reply to #21

Re: Solar Eclipse

08/17/2017 6:05 PM

Yes I have....

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru

Join Date: Apr 2011
Posts: 6542
Good Answers: 241
#24
In reply to #17

Re: Solar Eclipse

08/18/2017 4:35 AM

No one is suggesting putting the Moon's surface in low Earth orbit nor floating the Moon's surface high in the Earth's atmosphere.

.

You seem to have misplaced the theme of this thread of the discussion.

It began with you informing everyone that any shade build with the Earth's atmosphere would not function well, if it functioned at all.

I responded calling your assertion of poor or no function into question.

...and that's when your response began drifting.

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9
#25
In reply to #24

Re: Solar Eclipse

08/18/2017 8:42 AM

Problem is when people called it a shade.

Register to Reply
Guru

Join Date: Apr 2011
Posts: 6542
Good Answers: 241
#28
In reply to #25

Re: Solar Eclipse

08/18/2017 10:41 AM

"Problem is when people call it a shade"

.

To what does 'it' refer? The Moon during an eclipse? An overhead cloud producing a shadow over your location? Any other object/substance between a monitored position and the sun which reduces direct radiation incident on that position?

.

Also, where is the 3% lunar abledo figure originating? Average lunar abledo in the visible is in the neighborhood of 12%.

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19209
Good Answers: 1125
#37
In reply to #28

Re: Solar Eclipse

08/19/2017 8:00 PM

..."With an average albedo of 0.37, 63% of incoming solar energy contributes to the warmth of our planet."...

http://www.asterism.org/tutorials/tut26-1.htm

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply Score 2 for Off Topic
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19977
Good Answers: 749
#38
In reply to #37

Re: Solar Eclipse

08/19/2017 8:39 PM

This was about albedo of the moon, not of the earth.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
Hobbies - RC Aircraft - New Member

Join Date: Aug 2007
Posts: 686
Good Answers: 9
#39
In reply to #38

Re: Solar Eclipse

08/19/2017 9:31 PM

And AGAIN..... Solar Eclipse has absolutely zero to do with reflections. UG!

Register to Reply Score 1 for Off Topic
Guru

Join Date: Apr 2011
Posts: 6542
Good Answers: 241
#40
In reply to #39

Re: Solar Eclipse

08/20/2017 11:43 AM

You keep saying that. Repeating your premise when asked for support doesn't help. It would be difficult to accept the idea that the area just outside the penumbra doesn't receive additional sunlight reflected off the moons surface at highly oblique angles.

Now you are bringing tempetature into the mix. Let's leave that out until you get the previous sorted first.

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13438
Good Answers: 152
#26

Re: Solar Eclipse

08/18/2017 9:13 AM

I see that your curiosity has been met with 100 miles diameter disk in geostationary orbit, or near polar orbit 1 mile disk in LEO.

I will do you one even better. Pull up Google Earth, zero in on the southern tip of Spain, west of Gibraltar, in the Almeria desert zone.

Almeria greenhouse district

This district has 2-3 °C lower annual average temperature than they used to have.

From space, it looks like a snow storm has covered this portion of Beautiful Spain.

Almeria produces much of the produce for Europe's fresh vegetable and fruit demand. It is a wonderful, productive, and lucrative area. Here's wishing Spain and their partners full and continued success in all endeavors!

No need for dead-end space projects that cost in the millions or billions with no further return on investment.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply Score 1 for Good Answer
Guru

Join Date: Apr 2011
Posts: 6542
Good Answers: 241
#29
In reply to #26

Re: Solar Eclipse

08/18/2017 10:43 AM

Great reply, James.

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13438
Good Answers: 152
#30
In reply to #29

Re: Solar Eclipse

08/18/2017 10:52 AM

Why thank you, good buddy! Hopefully now that I am out of blog jail, I will behave much more suitably, having been "reformed."

I really had no excuse for my online behavior, so I got the hammer.

The only excuse I thought about was the stress of my wife going through two surgeries and the last one really affecting her energy level to a great extent; along with the unsteadiness of her hands and her loss of appetite, I was spending a lot of mental energy on stress and worry. No excuse whatsoever, so here I am two weeks later, hopefully permanently better for it.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Apr 2011
Posts: 6542
Good Answers: 241
#32
In reply to #30

Re: Solar Eclipse

08/18/2017 12:27 PM

How is she doing? Better? Putting all that behind her, I hope?

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13438
Good Answers: 152
#34
In reply to #32

Re: Solar Eclipse

08/18/2017 1:42 PM

She and I are both searching for the missing ingredient in her (poor) diet, that is resulting in her having trembling fingers/hands. For about 10 weeks, she has avoided all foods high in fiber - not something for the faint of heart.

Now she is at least to begin enjoying more of a "normal" diet, although she eats like a bird (a small one). Grilled chicken market salad from Chik-Fil-A is a mainstay.

Peanut butter is another of her mainstays, along with milk and corn flakes. Chicken/rice soup also. I cook her a steak on the grill (well-done is her preference, not mine), and she turns up her nose to it. It is not my cooking skill that is lacking, as she lost her sense of smell to a cold remedy (sinus spray?) that contained zinc salts, and that remedy literally shut down her senses of smell and taste.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain, and now disconnecting as Little England and Wales (not too sure about Wales bit, either). Kettle's on.
Posts: 26689
Good Answers: 700
#27

Re: Solar Eclipse

08/18/2017 9:37 AM

Of course, any shading device would need to be orbiting slower than geosynchronous, otherwise the eclipse would only be total for around 2min 45sec every few years or so...

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13438
Good Answers: 152
#31

Re: Solar Eclipse

08/18/2017 11:18 AM

grid parameters may fluctuate during eclipse

Workers will be monitoring line frequency more diligently during the eclipse, expecting changes in "diversity" and "predictability" of system load, on various interconnects.

Increasing line frequency means too little load for firm generation dispatched.

Decreasing line frequency means the opposite.

Good thing the jolly green giant stays out in his own field most of the time.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Apr 2010
Posts: 5740
Good Answers: 575
#33

Re: Solar Eclipse

08/18/2017 1:28 PM

Assuming that you put a 192-mile diameter "moon" in geosynchronous orbit over the equator above North and South America, there would be a series of eclipses daily at some latitude during the spring and fall only in the western hemisphere when the sun's declination is less than +/- 10.33 degrees.

Earth Radius = 4000,

Geo distance =22300,

asin(4000/22300) = 10.33 deg

The declination of the sun.

https://plus.maths.org/content/comment/reply/2168

Register to Reply
Register to Reply 42 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

adreasler (2); James Stewart (6); JE in Chicago (1); JPool (1); Mikerho (1); NSS (7); PWSlack (1); Rixter (2); SolarEagle (9); Tornado (2); truth is not a compromise (7); Usbport (3)

Previous in Forum: The Beginning of the End of Tesla   Next in Forum: Atlas V Launch Success

Advertisement