One thing I do not understand. Two facts that I cannot reconcile.
1. Mercury and Venus both come roughly between us and the sun several times a year, yet it is rare for them to come directly between us and the sun.
2. We can find planets going around other stars because these planets go between us and their sun. When we observe this we see it happen every time.
Would have thought that planets going around other suns would rarely go between their sun and us for the same reason that Mercury and Venus rarely go between the sun and us.