Perihelion an aphelion
The perihelion is the pynt in the orbit o a planet, minor planet, or comet, whaur it is nearest tae its pynt o orbit, generally a starn. It is the opposite o aphelion, which is the pynt in the orbit whaur the celestial body is farthest frae its pynt o orbit.
- "Perihelion and Aphelion". National Earth Science Teachers Association (NESTA). Retrieved 2015-09-19.