Definition

A point in the orbit of a celestial body where it is either closest to or farthest from the center of attraction, such as a star or planet.

Example

The satellite reached its apsis, where it was farthest from the Earth.

Conversation

Did you know that the Earth's orbit has an apsis?

Really? I thought it just went in a perfect circle.

It's interesting because the apsis is where it’s closest and farthest from the sun.

That makes sense! I guess orbits are more complicated than they look.

Synonyms & Antonyms

Root Explanation

Apsis → It comes from the Greek word "apsis" (ἁψίς), meaning arch or curve. In astronomy, it refers to the points of greatest and least distance of a celestial body from its focus, emphasizing the curved path of its orbit.

Memory Tip

Imagine the curved path of a planet around a star — that's what 'apsis' refers to, highlighting the arch or curve in its orbit.

Visually Confused Words