Mercury at superior solar conjunction
2013 Aug 24
From our vantage point on the Earth, Mercury will appear to pass around the far side of the Sun, moving to within a mere 01°45′ of it in the night sky and becoming totally lost in its glare. Mercury will also pass apogee – the time when it is most distant from the Earth – within a few days of the same time, since it will lie exactly opposite to the Earth in the Solar System. It will move to a distance of 1.36 AU from the Earth, making it appear at its smallest in the night sky. If it could be observed, it would measure 4.9 arcsec in diameter, whilst appearing completely illuminated.