Greatest Elongation

Demonstrate an understanding of the terms: ... greatest elongation...

We see an inferior planet angle best when it is at a position forming 90° between the Sun and Earth.

The remaining angle is the angle of elongation (e).

Elongation is the angle at which we see an inferior planet, which means that Venus never moves 47° away from the Sun. Mercury has a a maximum elongation of 22°.


Drag & Drop
  • Explain the term elongation
  • Explain why we see inferior planets best at the maximum angle of elongation

Thinkquest Elongation