Dear Roser, Willy Leenders is quite right that...
PERIGEE is the point in the orbit of the moon or a satellite at which it is nearest to the earth. BUT... Strictly, this is when the centre of the moon is nearest the centre of the Earth. YOU are unlikely to be at the centre of the Earth at the critical moment :-) This can be important... ...as the Earth rotates it carries you with it and in certain circumstances you can (I think!) be nearer to the moon a few hours before or after perigee than at the instant of perigee. Other things being equal, you are nearer the moon when it is at its highest point than you are at moonrise or moonset. This means that the moon's angular diameter is actually larger when the moon is at its highest point than at moonrise and moonset. The fact that the moon APPEARS to be larger when it is close to the horizon is an illusion, albeit a very delightful one. You will wish you had never asked the question :-) Frank H. King Cambridge, UK --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
