Mercury at inferior solar conjunction

2014 Oct 16

From our vantage point on the Earth, Mercury will appear to pass around the near side of the Sun, almost crossing between the Sun and us. As it does so, it will pass within a mere 01°28′ of it in the night sky and becoming totally lost in its glare. Mercury will also pass perigee – the time when it is closest to the Earth – within a few days of the same time, since it will lie on exactly the same side of the Sun as the Earth in the Solar System. It will move to within a distance of 0.67 AU from the Earth, making it appear at its largest in the night sky. If it could be observed, it would measure 10.1 arcsec in diameter, whilst appearing completely unilluminated.

Mercury’s reaching inferior conjunction marks the end of its apparition in the evening sky and its transition to become a morning object over the next few weeks.