Posted: May 11, 2016 6:42 am
It's kinda surprising this only happens about every 7 years when you think about how far away we are and how big the sun is, plus mercury 's year is about 3 months. If someone asked me how often this would occur, I would have guessed way higher, maybe more than once a year. So my thinking has mercury too close [to the sun] with less difference in inclination.