Morning, Moon, and Mercury . ... Credit Copyright: Stephen Mudge Explanation: Last week Mercury wandered far to the west of the Sun. As the solar system's innermost planet neared its greatest elongation or greatest angle from the Sun (for this apparition about 27 degrees) it was joined by an old crescent Moon . ... Mercury's track is at the far right, separated from the Moon's path by about 8 degrees. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...