APOD: Ganymede from Juno (2023 Nov 28)

[johnnydeep]

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.

Ok, but I guess I'll just have to be too colloquial regarding this particular terminology.

It's clear what you mean, which is what's most important.

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]

Ok, but I guess I'll just have to be too colloquial regarding this particular terminology.

It's clear what you mean, which is what's most important.

My (rigorous?) definition would be: orbit A is more circular than orbit B if e(A) < e(B), where e is the eccentricity.

That's certainly how I interpreted your wording.

[johnnydeep]

It's clear what you mean, which is what's most important.

My (rigorous?) definition would be: orbit A is more circular than orbit B if e(A) < e(B), where e is the eccentricity.

That's certainly how I interpreted your wording.

Ok, good.