Tonight and tomorrow night Mars and Neptune will be under a degree apart. But, as the pair is quite low in the sky, this may not be observable. The planets will be 40′ apart tonight, a little closer tomorrow at only 27′ separation. The pair will be 14° above the horizon at sunset. Mars, shining a 1.2 magnitude should be relatively easy to spot. The 8th magnitude Neptune may be too dim to see, even with a telescope, against the bright glow of sunset.
On the evening of February 5th, Mercury will join in to create a trio, just 2° below Mars with Neptune between the two.