One strange occurrence you can witness during a planetary transit is the teardrop effect. This occurs when Earth's atmosphere distorts the transiting planet during 2nd or 3rd contact to produce a teardrop shaped planet.
Location: Creston Junction and I-80, WY
Camera: Canon XSi (modifed)
Telescope: WO 110FLT
Filter: Herschel Solar Wedge with 3.0 ND and Continuum Filter
1x1/100th second ISO 200
1x1/1000th second ISO 200
Processing: Photoshop, Topaz