The exact date of Mercury’s greatest elongation west this summer is Aug. 2, but you can still see it within a week of the event. Greatest elongation west just means that Mercury is farthest from the sun in the morning sky. Every other state that falls in the path has a chance to see a 10% partial eclipse. The partial solar eclipse is paired with a partial lunar eclipse later this month. Aug. 27-28 — Partial lunar eclipseTo close out the second eclipse season of this year, we have a partial lunar eclipse.