Observing Jupiter, the Great Giant Planet

The largest planet of our Solar System, Jupiter is easy to see with the naked eye and can be viewed several exciting ways with equipment. What if you too took a crack at discovering it? In 2020, this planet can be observed from as early as spring until the end of December.

View of Jupiter from the Juno probe during its 26th orbit around the giant planet in spring 2020. We can see the details of its cloud bands and hurricanes, including the Great Red Spot.
View of Jupiter from the Juno probe during its 26th orbit around the giant planet in spring 2020. Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M.Gill

En exciting planet that’s easy to find

Jupiter is a bright celestial body that’s easy to see with the naked eye thanks to its dazzling shine that dominates the surrounding night sky. Beginners could confuse it with Venus, though Jupiter is not as bright as “the Morning Star” due to its distance from Earth. Eleven times the diameter of Earth, this giant planet can easily be admired with the help of a simple telescope. Your observation won’t reveal as many details as the photos taken by space probes, but you can discover Jupiter’s cloud bands—and four main moons, which can be viewed with just a simple pair of binoculars!

When Can Jupiter Be Seen?

In springtime, Jupiter is readily visible during the second half of the night and gradually comes up earlier each evening. On July 14th, the giant planet is in opposition with the SunDuring the weeks that surround this date, Jupiter will be visible all night long and, due to its proximity to Earth (619 million kilometers on July 14th, 2020), observation conditions will be perfect. Warm summer nights will make observation easier, even if this planet remains relatively low on the horizon (by using metropolitan France’s latitudes, this will not exceed 20°, or the width of an outstretched hand). Observers located further south will have an advantage, since a lower or even negative observation latitude means the planet will be higher in the sky.

Photo of amateur astronomers observing the starry sky, with the constellation Leo and Jupiter looking like a bright speck of light just above their heads.
Jupiter is incredibly bright as this photo shows, which was taken in spring 2016 when Jupiter drifted in between the paws of the constellation Leo. Photo: Jean-Baptiste Feldmann

Jupiter is easily visible throughout summer and fall 2020. The last possible observations of this giant planet will be in December at the beginning of the night, near the western horizon. Jupiter will be especially interesting to observe on certain dates because it lines up in particular configurations with Saturn or the Sun. You can find these details below!

How to Spot Jupiter?

Map showing the trajectory of Jupiter in 2020, between constallations Capricorn and Sagittarius.
In 2020, Jupiter is found above the east-southeast horizon between the constellations Capricornus and Sagittarius. Saturn, which orbits nearby, is not shown here. You can also verify the position of the two planets on the Stelvision sky map online.

It should be known that Jupiter is incredibly bright! It outshines all the visible stars in the sky, though it still doesn’t hold a candle to the brightness of Venus. To find Jupiter, turn towards the east-southeast horizon. In 2020, it orbits in the constellation Sagittarius, not far from its ringed partner Saturn. However, you don’t have to worry about mixing them up, since Jupiter is much brighter.

What Can You See with Equipment?

A photo taken by an amateur astronomer showing Jupiter's cloud bands and the shadow of a probe on its surface.
Well-equipped amateur astronomers with a fair amount of experience can photograph various details of Jupiter’s surface such as its intricate cloud bands, Great Red Spot, and the shadows of nearby probes. With a little refractor telescope or simple reflector telescope (simulation found in the box), you can take photos of belts, zones, moons, etc., that will be less detailed but just as interesting. Photo: Philippe Renauld – Simulation : Stellarium

Jupiter is a favorite amongst even the most modestly equipped of amateur astronomers. By looking at this planet through a simple telescope, you’ll be able to immediately see a disc, whereas the surrounding stars remain small dots due to their far-off distance.

You can also easily see how the planet is striped with cloud bands. A small telescope will generally reveal Jupiter’s two main bands, known as its equatorial belts.

Violent winds from Jupiter’s atmosphere also produce the famous Great Red Spot, a giant hurricane that has been raging since multiple centuries and reaches speeds of up to 425 miles (700 km) per hour! This spot, which is three times the size of Earth, can be viewed by an attentive observer with a telescope boasting a focal length of at least 100 mm in diameter. This Great Red Spot is in fact not really even very red, but it can be made out from the surrounding equatorial belt by its different color. The Great Red Spot gives you the opportunity to see the impressive rotation speed of the planet, which completes a full rotation on its access in just ten hours!

This video made at the Pic du Midi (France) shows in incredible detail Jupiter’s rotation. Famous for its extraordinarily stable atmosphere which favors high-resolution shots, it’s no wonder this observatory is the capital of planetary astronomy!

Even more details can be seen, particularly of Jupiter’s complex and numerous cloud bands, with a telescope of 150 mm or more in diameter. However, a truly detailed image can only be obtained if the atmosphere is stable and free of turbulence, and if the equipment is well tuned (pay attention to collimating the mirrors for a Newtonian reflector telescope).

However, the most striking thing about Jupiter is the fact that it is not alone! Small pinpricks of light are roughly lined up on either side of this giant planet. These are the main moons of Jupiter, discovered by Galileo four centuries ago with a rudimentary telescope. These four so-called Galilean satellites (or moons) are called Io, Europa, Ganymede, and Callisto. All four of them cannot always be seen, since certain are sometimes hidden behind the planet or pass just in front of it.

This very detailed image of Jupiter and two of its moons, Europa and Io, was taken by the talented astrophotographer Marc Delcroix.
This very detailed image of Jupiter and two of its moons, Europa and Io, was taken by the talented astrophotographer Marc Delcroix. Image from the Stelvision photo competition No. 27

Since these moons circle Jupiter in a few days, it is great to observe their evolution night after night.

And with a pair of binoculars?

Binoculars don’t magnify enough to see details on Jupiter’s surface. But the moons are visible!

If possible, mount your binoculars on a tripod, a low wall, or even a broomstick so that it doesn’t shake. With careful observation, you will most likely come across several small pinpricks of light near either side of the planet. Surprise your friends by showing them this incredible sight!

However, if the moons are too close to or behind the planet, you won’t be able to see them. Use the simulator below to check their position.

A Simulation of the Position of Jupiter’s Moons

Here are the positions of Io (I), Europe (E), Ganymede (G), and Callisto (C). View north at the top, west on the right. Have fun comparing this with what you see in real life! (Note: the image will appear inverted with certain equipment). The moon positions are set using Javascript, which is disabled in your browser. You’ll need to turn it back on if you want to see the current position of Jupiter’s moons.
You can set the specific date:

Time frame: 100 milliseconds

The satellite position calculation software is Copyright © 2000 – 2013 Akkana Peck, under GNU Public License v.2.

Sightings of Jupiter Not to Be Missed in 2020

From July to December 2020, the planet Jupiter is orbiting in conjunction with another remarkable giant planet, Saturn. This proximity will give you the chance to see incredible sights almost every month as the Moon passes close by. But July 23rd and December 21st are also two other major dates worth remembering! Check out what awaits you below.

On July 14th, Jupiter is in opposition. This means that the planet is closest to Earth and its apparent diameter is the largest for 2020. It is also the moment when the planet is the brightest (magnitude -2.8).

Map showing the positions of Jupiter and Saturday on July 14th, 2020 around 11:00 p.m., when Jupiter is closest to Earth.
Positions of Jupiter and Saturn on July 14th, 2020 in the evening, when Jupiter is closest to Earth.

On July 23rd at dawn, observe Jupiter in the company of all the other planets in the Solar System for a real planet marathon! It is truly rare to see all the planets at the same time, so you don’t want to miss it. Jupiter, Saturn, Mars, Venus, and Mercury will be easily visible to the naked eye. However, you’ll need a telescope to see Uranus, Neptune, and Pluto.

On the night of August 1st to the 2nd, the nearly full Moon will neighbor Jupiter and Saturn throughout the night.

During the nights of August 28th to 29th and September 25th to 26th, the gibbous Moon again accompanies the two giant planets, located once again between Sagittarius and Capricorn.

On the evening of October 22nd, the crescent Moon accompanies Saturn and Jupiter until they set in the southwestern horizon.

On the evening of November 19th, the crescent Moon still spends part of the night in the company of the gradually approaching planets Saturn and Jupiter.

On December 17th at about 6:30 p.m., the Moon’s very thin crescent is at 6° to the remarkably close Jupiter-Saturn duo.

Finally, on December 21st in the early hours of the night, don’t miss seeing Saturn and Jupiter brush past each other at 0.1°!

Simulation of Saturn and Jupiter surrounded by their moons, which will be visible through a telescope with magnification of 31x on December 21st, 2020.
Saturn and Jupiter surrounded by their moons, which will be visible through a telescope with magnification of 31x on December 21st, 2020.

So Much More to Discover…

Jupiter is an exciting planet that still holds many secrets. Scientists are still studying it from Earth. In May 2020, they used the Gemini telescope in Hawaii to capture through infrared light the most distinct and precise details of Jupiter’s atmosphere ever seen from the ground. These images are strangely beautiful not only because their colors are unusual, but they will also help scientists better understand how the giant planet’s stormy atmosphere works.

Image showing Jupiter's atmosphere captured in infrared light from the Gemini telescope in Hawaii.
The atmosphere of the planet Jupiter captured in infrared light from the Gemini telescope in Hawaii. Credit: International Gemini Observatory/NOIRLab/NSF/AURA M.H. Wong (UC Berkeley)/Mahdi Zamani

Several probes have also explored Jupiter since 1973. Today, the American probe Juno orbits the giant planet.

Europe is also planning an ambitious mission with the Jupiter Icy Moon Explorer (JUICE), which is scheduled for launch in 2022 and anticipated to arrive on site in 2030. JUICE will explore three of Jupiter’s Galilean moons (Callisto, Europa, and Ganymede), each suspected of harboring an ocean beneath an icy crust.

These images taken by professionals are spectacular, but don’t let them prevent you from doing your own exploration of the giant planet. It is sure to incite wonder—so off to your telescopes!