But even with the smallest telescope, you can see structure in the atmosphere, usually two dark bands surrounded by lighter regions. To see any detail on the face of Jupiter, a telescope is required. Layout of the belts and zones of Jupiter (University of Wisconsin)Īs backyard observational astronomers, we are most interested in the part of Jupiter we can see: the outer layers of the atmosphere. Their outer layers are made entirely of clouds further down the gas turns to compressed liquid, and at the very center of these planets may be a rocky carbon core. Gas and ice giants do not have well defined rocky surfaces like the Earth.

(Uranus and Neptune are also sometimes called gas giants, or, because they are much colder, “ice giants”). Like Saturn, Jupiter is a “gas giant”, a massive planet made up almost entirely of cold hydrogen and helium gas along with traces of other gases like ammonia and methane. The planet is 2.5x as massive as all other planets combined. Jupiter is the largest planet and, by far, the largest object in the solar system save for the Sun. This is the view seen from about 45 degrees north latitude. It is the brightest object in this part of the sky, and the brightest object in the entire night sky except for the Moon and Venus. Jupiter in mid-August 2021 lies opposite the Sun in the constellation Capricornus. Its disk spans nearly 48″ as seen from our point of view. At opposition, Jupiter shines at magnitude -2.9, brighter than anything else in the night sky except for Venus and the Moon and lies about 621 million kilometers from Earth. It resumes its eastward (prograde) motion on October 18. The planet has been retrograding westward against the background stars a little each day since June 21. This year Jupiter reaches opposition in the southern reaches of the ecliptic in the eastern part of the constellation Capricornus, just over the border from Aquarius (see below). The visible face of Jupiter reveals so many interesting features in a small telescope that the planet is a favorite target for new and experienced stargazers. You can’t miss it: the planet is by far the brightest object in the southeastern sky as night gets underway in the northern hemisphere and nearly overhead in the southern hemisphere. A couple of months before and after this date, Jupiter is in perfect position for viewing with a small telescope, or even a pair of binoculars. Jupiter reaches a position for optimum viewing in a telescope once every 13 months, roughly, and it makes its latest closest approach to Earth on Augat 0h Universal Time when the planet appears in the extreme eastern part of the constellation Capricornus. It’s brighter than any star, and is only outshone by the planet Venus and the Moon, and, very rarely, by Mars and Mercury. The planet Jupiter is always one of the brightest objects in the night sky.

Jupiter through home telescope