The innermost planet Mercury is moving into view above the western horizon at sunset. For about the next two weeks Mercury will gradually move eastward away from the Sun, increasing the angle between them and setting a little later each evening. By the 31st, as this animated graphic is showing, Mercury will have reached its greatest eastern elongation and from that date forward Mercury will be moving westward back toward the Sun and inferior conjunction next month.
Mercury recently was in superior conjunction, on the opposite side of the Sun from the Earth, and is now moving eastward away from the Sun. During this time Mercury’s orbit will be bringing it closer to the Earth and as a result Mercury’s appearance will undergo phase and apparent size changes as it wanes from a small gibbous to a larger near quarter phase.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.