My (rigorous?) definition would be: orbit A is more circular than orbit B if e(A) < e(B), where e is the eccentricity.Chris Peterson wrote: ↑Thu Nov 30, 2023 9:27 pmIt's clear what you mean, which is what's most important.johnnydeep wrote: ↑Thu Nov 30, 2023 9:10 pmOk, but I guess I'll just have to be too colloquial regarding this particular terminology.Chris Peterson wrote: ↑Thu Nov 30, 2023 12:10 am
It's just too colloquial for my taste. Orbital elements are well defined. There is no concept of "circular" or "diameter". Every orbit is elliptical, where that ellipse is defined by an eccentricity and a semimajor axis. It happens that if the eccentricity is zero, the orbit is circular, and the semimajor axis is the same as the radius. But those aren't the best terms.![]()
APOD: Ganymede from Juno (2023 Nov 28)
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Re: APOD: Ganymede from Juno (2023 Nov 28)
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}
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Re: APOD: Ganymede from Juno (2023 Nov 28)
That's certainly how I interpreted your wording.johnnydeep wrote: ↑Thu Nov 30, 2023 9:40 pmMy (rigorous?) definition would be: orbit A is more circular than orbit B if e(A) < e(B), where e is the eccentricity.Chris Peterson wrote: ↑Thu Nov 30, 2023 9:27 pmIt's clear what you mean, which is what's most important.johnnydeep wrote: ↑Thu Nov 30, 2023 9:10 pm
Ok, but I guess I'll just have to be too colloquial regarding this particular terminology.![]()
Chris
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Chris L Peterson
Cloudbait Observatory
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Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
- johnnydeep
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Re: APOD: Ganymede from Juno (2023 Nov 28)
Ok, good.Chris Peterson wrote: ↑Thu Nov 30, 2023 9:41 pmThat's certainly how I interpreted your wording.johnnydeep wrote: ↑Thu Nov 30, 2023 9:40 pmMy (rigorous?) definition would be: orbit A is more circular than orbit B if e(A) < e(B), where e is the eccentricity.Chris Peterson wrote: ↑Thu Nov 30, 2023 9:27 pm
It's clear what you mean, which is what's most important.
![:) :ssmile:](./images/smilies/smile.gif)
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}