The planets form a line that rises from the horizon in the western sky and will be best seen on Thursday, October 18, after sunset. But throughout the month, these planets will be visible in the same general areas of the sky.
Mercury and Venus will be most clearly west and closer to the horizon, while Saturn will be higher in the sky and northwest, Mars will be even higher visible. On the night of October 18 Venus and Mercury will stand side by side. Since Mercury is the weakest and hardest to see of these planets, Mercury will be much easier to see with an ultra-bright Venus at its side.
Later in the month, October 24, you might also see Uranus and Neptune in the night sky ̵
This fantastic sight does not always happen that often. While the planets 2018 were so visible for the second time and were also visible twice in 2016, it had been a decade before that the five brightest planets were so visible together in the night sky.
The next time the five brightest planets are aligned in the night sky in this way, it will be in July 2020, but instead of being as close to each other as they will appear this month, they will be stretched across the sky and possibly harder to see.