The New Year begins with the closest planetary-planetary conjunction of 2017 as Mars passes just 1 arc minute south of Neptune, which corresponds to an apparent separation of just 1/30 the diameter of the full Moon. The planets will be visible in the evening sky just after sunset towards the west. At mag. +0.9, Mars can be easily spotted with the naked eye while Neptune (mag. +7.9) requires at least a pair of binoculars or a small telescope to be seen. Also located in the same region, providing nice viewing, is much more brilliant Venus (mag. -4.4) and the crescent Moon.
Once the sky is dark enough look at Mars through binoculars or a telescope and you should be able to spot Neptune close by. For comparison, Mars is 250 times brighter than Neptune and appears orange-red in colour while Neptune is pale blue. Of course this is a purely line of sight alignment. In reality, Neptune is more than 18 times distant than Mars.
Later on January 13th, the second planetary-planetary of the year occurs when Venus passes 0.4 degrees north of Neptune.