On Monday, 14 November, the moon will be the biggest and brightest it has been in more than 60 years. Exactly what causes the moon illusion is still a matter of debate. When the supermoon coincides with a very stretched out ellipse, a supermoon is even closer (and bigger). As the eccentricity closer to one, the ellipse gets more and more stretched-out. Now, the moon’s eccentricity has an average value of just 0.0549, making it incredibly close to a circle.

Source: The Guardian November 10, 2016 07:10 UTC