Just for fun, I like to visually spot all seven of the major planets in a single night when circumstances permit, with unaided eyes and small optics like binoculars. The current (and soon to end) evening elongation of Mercury provided many opportunities, and I ended up doing it five times. I would start with Mercury, and failure there would end the night’s effort. I also like to spot other solar system objects along the way; for example, the Moon, the minor planet/asteroid (4) Vesta, and in one case, a comet, C/2017 S3 (PANSTARRS). Although I often pick up one or more artificial satellites while I’m out looking (possibly the ISS), I don’t include these man-made objects.
Perhaps arbitrarily, I’m little concerned about trying to see dim (134340) Pluto. I’ve seen it many times in the past, but I would need my 12.5-inch Newtonian to do it, and even with that scope, it’s borderline because of its inherent dimness coupled with atmospheric extinction at its current low altitude in Sagittarius. It would also require going from my suburban location to the relatively dark New Jersey Pinelands.
The last time I saw all the planets in one night was July 19-20, 2018, and to make it a slightly more challenging, I decided that I had to see each object in my 85 mm spotting scope (which has no finder scope). Of course, bright objects like Venus, Jupiter, Saturn, Mars and the Moon aren’t challenging (but they had shown surprising detail in the spotter), and when you follow them on a regular basis with binoculars, Vesta, Neptune and Uranus are fairly easy to locate, as was C/2017 S3 this time. Mercury is probably the trickiest one, mainly because of the fickle nature of clouds. It can be wonderfully clear in most of the sky, but there are often streaky clouds along the respective area of the horizon anyway, so it’s pot luck finding it between clouds. Even when it’s clear along the horizon, Mercury’s varying brightness, residual twilight and/or an unfavorable angle of the ecliptic may require binoculars to find it or even see it.