Tonight, if you have a clear sky, set a goal for yourself of seeing all five visible planets. Byvisible planet, we mean any solar system planet that’s readily visible to the unaided eye. In their order going outward from the sun, the five visible planets are Mercury, Venus, Mars, (Earth), Jupiter and Saturn. These worlds have been observed by our ancestors since time immemorial.
Best of all, you don’t have to stay up all hours of the night to see these five visible planets. You can catch Mercury, Venus and Mars in the southwest at nightfall, Jupiter in the east at early-to-mid evening and Saturn in the southeast before dawn.
As dusk gives way to darkness, or about 60 to 75 minutes after sunset, look for Venus, Mercury and Mars in the direction of sunset. Mercury poses the biggest challenge because it’s the first planet to set behind the sun. If you can’t see Mercury with the unaided eye, you can always resort to binoculars. Aim them at dazzling Venus – which is easily visible above the sunset point. Then sweep with your binoculars, below Venus in the direction of the sunset point, to view Mercury in the same binocular field. Keep in mind that Mercury follows the sun beneath the horizon about 75 minutes later. Venus does likewise, a short time after Mercury.
Fortunately, the red planet Mars stays out for a couple hours after Mercury and Venus set. Mars is only modestly bright. Nonetheless, it is easy to see with the unaided eye. Roughly four hours after sunset, or after Mars has set in the west, look for super-brilliant Jupiter to rise in the east. Jupiter should be high enough to view by bedtime, even if your eastern view is somewhat obstructed by mountains or trees.
Once Jupiter climbs over the eastern horizon, it stays out for rest of the night. Jupiter swings up to its high point for the night around 2 to 3 a.m. (that’s local time, the time on your clock no matter where you are on Earth). Jupiter shines in the west just before dawn. Jupiter will be hard to miss, for this brilliant beauty outshines any star.
Saturn, the sixth planet outward from the sun, rises several hours before sunrise, lighting up the southeast sky during the predawn hours. Shortly before dawn, look for golden Saturn to shine above the red star Antares. Both are toward the sunrise direction.
Bottom line: Given clear skies, the five visible planets – Mercury, Venus, Mars, Jupiter and Saturn – should be yours to behold on these January 2015 nights.
excerpts from earthsky.org