Neptune at solar conjunction
2014 Feb 23
From our vantage point on the Earth, Neptune will be unobservable as is passes around the far side of the Sun from the Earth. At its closest approach to the Sun in the night sky, Neptune will be a mere 00°40′ away from it, becoming totally lost in the Sun’s glare for several weeks.
At around the same time, Neptune will also be at its most distant from the Earth – receding to a distance of 30.97 AU since the two planets will lie on opposite sides of the Solar System.
As a result, not only will Neptune be unobservable on account of its closeness to the Sun in the sky, but it would also – if it could be observed – appear at its smallest and faintest. If it could be seen, it would measure 2.2 arcsec in diameter.