... Credit Copyright: SOHO - LASCO Consortium, ESA , NASA Explanation: In astronomical parlance , an interior planet is at superior conjunction when it is located on the opposite side of the Sun from Earth. Mercury , the solar system's innermost planet, zips past this point in its orbit today. In fact, this recent picture from a solar coronagraph on board the the space-based SOHO observatory shows Mercury positioned very close to the Sun as seen from a near Earth vantage point. ...