Mercury is at aphelion, its furthest point from the Sun. Fortunately, it’s still well placed for Earth-bound observers and can seen in the pre-dawn sky. Meanwhile, Venus is on the opposite side of the Sun and both that world and Mars can be seen in the early evening sky.
(Click on an image to enlarge.)
Images courtesy of Mobile Observatory.
20:12 UT – Mercury is at aphelion. Distance to Sun: 0.467 AU (72% illuminated, magnitude 0.0, diameter 6.0”. Naked eye, Capricornus, pre-dawn sky. See image above.)
Learn more about every upcoming astronomical event in 2015 An Astronomical Year (Kindle eBook) and The Astronomical Almanac (2015-2019) (Kindle eBook) and The Astronomical Almanac (2015-2019) (Paperback Edition).
The Amateur Astronomer’s Notebook allows astronomers to log 150 observing sessions and includes an appendix of hundreds of suggested deep sky objects.