The naked-eye planets enter those zodiac constellations located along the ecliptic for various amounts of time throughout the year, depending upon their position in the solar system. For instance, those closest to the Sun like Mercury and Venus will spend less than a month in any particular sign, while an outer planet like Saturn will spend around 2.5 years before moving into the next zodiac constellation.
With that in mind, those stargazers who regularly turn their attention to the night sky will not have failed to notice the planet Jupiter shining far brighter than the brightest star Sirius for several months now. The king of planets spends around one year visiting each zodiac constellation, and in August of 2016 moved from Leo into Virgo, and there it shall remain until September 2017.
Stargazers should therefore make the most of the great opportunity presented to them for viewing this incredibly bright and impressive night sky object. Even to the unaided eye, Jupiter makes an incredibly impressive site in the night sky, shining with a luminosity of -2.3 in April, and outshining the nearby constelation’s of Virgo’s brightest star, Spica, which has a visual magnitude of +0.97. The use of even a cheap pair of 7×50 binoculars would then allow you to glimpse Jupiter’s four main moons, Io, Europa, Ganymede and Callisto, all named after lover’s of the mythological king of the gods. A small 4.5″ reflector telescope, on the other hand, will bring into focus the planet’s Great Red Spot, a giant anticyclonic storm about 12,400 miles long and 7,500 miles wide that has been raging for centuries, as well as the planet’s ammonia clouds that appear as white and colorful horizontal bands across Jupiter’s entire globe.
And then there is a plethora of mobile astronomy apps which are perfect for studying Jupiter, which for iOS users include the Gas Giants app, the Sky & Telescope app called JupiterMoons, and the Jupiter Guide app. Android users, on the other hand, might consider checking out the Jupiter Simulator app.
Currently, Jupiter rises in the southeast in the early evening and can be seen in the night sky before setting in the west a little before dawn, giving ample opportunity to study “the gas giant” in great detail over the coming months. By August, however, Jupiter will have sunk lower in the night before disappearing from view all together by mid-September, thereafter gradually becoming only a morning object by the year’s end.