Wednesday June 21st the innermost planet Mercury reaches superior conjunction – on the opposite side of the Sun from the Earth. For those that are curious, Mercury at superior conjunction is approximately 1.324 AU (123,073,489 miles; 198,067,580 km) from the Earth – the combined distance of the Earth to Sun distance plus the radius of Mercury’s orbit.
Mercury is not visible while in conjunction with the Sun but within the next week or so Mercury will reappear on the east side of the Sun and start becoming visible over the western horizon at sunset.
Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.