軌き道どう離り心しん率りつ

Meanings

1

orbital eccentricity

Technical term in astronomy describing how much an orbit deviates from a perfect circle.

Because this planet's orbital eccentricity is very small, it follows a nearly circular orbit.

軌き道どう離り心しん率りつが大おおきいほど、楕だ円えん軌き道どうは細ほそ長ながくなる。

The larger the orbital eccentricity, the more elongated the elliptical orbit becomes.

ratio, rate, proportion

離り心しん率りつ
General term for eccentricity in geometry; 軌道離心率 specifically refers to orbits.
軌き道どう
Means 'orbit' or 'trajectory'; 軌道離心率 is a property of an orbit.

Compound of 軌道 (orbit) and 離心率 (eccentricity).