Jupiter is one of the most popular planets in our solar system, a massive gas giant that is the largest of all the planets.
It has a massive appeal to both astronomers and laypeople, its gigantic body visible to the naked eye and through telescopes small and large.
Despite being further away from Earth than Mars, it is more visible for longer during the year, again owing to its size.
It also has more interesting and distinguishing features such as the red spot, which is a storm that has ravaged the surface for hundreds of years, along with a cornucopia of moons, some of which are bigger than planets.
But how massive is Jupiter? Put simply, you can fit Earth inside it 1,300 times. Jupiter will appear in our night sky at 29.8-inches, which is remarkable compared to the closest and smaller planet Mars, which only reaches a maximum of 25.1-inches.
One of the only times you’ll be able to see Jupiter is when it’s in opposition, that is, directly facing both Earth and the sun.
Jupiter in opposition is over 60% larger, perfect for telescope enthusiasts who want to see all its finer details. This is what makes Jupiter a top choice for backyard astronomers.
But which part of the sky is Jupiter on tonight? What telescopes are best to see this behemoth? How much should you be looking to spend on a decent telescope?
Well, whether you’re an amateur or professional star-spotter, we’ve got a comprehensive list of how to see Jupiter through a telescope. We’re also covering the best time of year to see Jupiter, as well as some of the landmark features that you should be looking for in or around its surface.
Some Fun Facts About Jupiter
Let’s start off with a few interesting facts about Jupiter that justifies its moniker as being the God kings of the solar system.
1. Jupiter is massive!
It’s no mystery that Jupiter is one of the biggest planets in the solar system. There was actually some speculation that Jupiter was actually a failed star, although this has since been disproven by the experts. The fact is that Jupiter is 2.5 bigger than all of the masses of the other planets combined.
If Jupiter increased in size, it would actually begin to get smaller, the added mass making the planet denser and causing it to collapse in on itself. Experts say that Jupiter could gain mass and still maintain at roughly the same size.
2. Jupiter, You Will Never Be A Star!
Jupiter does have similar properties to a star, being rich in both helium and hydrogen, however, the only difference is that Jupiter does not have enough mass to trigger fusion at its core.
This how stars are created, bonding hydrogen atoms at incredible heat and pressure, releasing light and heat in the process.
The process of star-making needs immense amounts of gravity, which Jupiter simply does not have. In fact, it would have to have over 70 times its current mass to become a star.
3. Jupiter Is A Fast Spinner
Of all the planets in the solar system, Jupiter is one of the fastest rotating for its size. It has a rotational velocity of around 12 kilometers per second, making only 10 hours to make a full rotation on its axis.
Its unique shape is because of its spinning speed - it’s very flat at both of its poles while bulging out at the sides. Its equator is more than 4,600 kilometers further from its core than the poles.
The powerful rotation is also what generates its powerful magnetic fields and the lethal radiation that surrounds it.
4. The Clouds Aren’t Very Thick
All the multitude of clouds on the surface isn’t very thick at all, with all those beautiful swirling clouds being only 50 kilometers in depths. This unique phenomenon is made from ammonia crystals broken up into two separate cloud decks.
The darker clouds are thought to be matter driven from the surface of Jupiter, which changes color when they react with the sunlight. Just below these darker clouds are hydrogen and helium.
5. The Great Red Spot is very, very old
One of the most distinguishing features of this planet is its red spot, which is actually a storm that has been there for at least 350 years - ever since we started observing it back in the 17th Century.
However, there is some dispute over whether the spot observed back then is the same one as we’re seeing today.
The Great Red Spot, as it’s known, is a persistent anticyclonic storm that is located just south of the equator, which measures around 24,000 kilometers in diameter and 12-14,000 kilometers in height. The spot itself is large enough to contain 3 planets the size of Earth.
However, owing to modern observations, the red spot appears to be shrinking slowly, although we cannot tell when it will disappear entirely. Scientists are relatively confident that another one will appear at some point.
How To Find Jupiter In The Night Sky
Being one of the brightest objects in the night sky, right behind Venus and the moon, you should have no trouble spotting it with your naked eyes.
But first, you need to know where you’re looking...
First Step: Is Jupiter Visible Tonight?
Like a lot of the other planets in the night sky, Jupiter likes to move around a lot, meaning that it will be unobservable for large portions of the year. So before you start looking through your binoculars, you need to know if it’ll be in the sky tonight.
One of the most accurate ways of doing this is by using sky tracking software, which will accurately tell you where the planets are in the sky this evening.
We would recommend a program called Stellarium, which you can also use to coordinate your location and to let you know when Jupiter will be coming into your eyeline.
Second Step: How To See Jupiter Without A Telescope
Both Jupiter and Saturn will form a planetary double act during the summer and fall of 2021, although they often spend the first week of January in the same vicinity as one of the smallest planets in the solar system, Mercury.
These 3 planets will form a neat triangle low in the west-southwest sky during the dusk hours of January.
Jupiter is the planet at the top of this triangle, being the brightest of the three at -1.9 magnitude, with Mercury at -0.9 and Saturn at -0.6.
After the first quarter of the year, Mercury will disappear, getting higher and higher above the horizon, while Saturn and Jupiter disappear into the sunset like a pair of hired guns. Jupiter will be the last to disappear, with both planets appearing in the morning sky towards the end of the month.
Third Step: How To See Jupiter With A Compact Telescope
Being one of the brightest stars in the sky, one of the best ways to see this beast is through a telescope. Luckily for those on a budget, because Jupiter is so big, you won’t have to fork out too much money on a top-of-the-range telescope to see it.
Even on a 4-inch telescope, you should be able to make out its defining features.
It is recommended that you start off at the lower levels of magnification, as this will increase your field of view and make it easier to get Jupiter in your sights before you hone in and focus on the target.
Looking into your eyepiece should be able to tell you if you have Jupiter in your sights or not. It will appear to you quite unlike the surrounding stars, being brighter and having more density, appearing as a disc. Use your focus to make the edges of this disc much more defined.
You might want to double-check that this is Jupiter and not another planet by quickly consulting your digital planet finder.
One giveaway is that you’ll notice dark or grey bands going across the face of Jupiter, which are its gases that make up a vast portion of its atmosphere. These are divided up into the following regions, from the top of the planet to the bottom:
- South polar region
- South temperate zone
- South temperate belt
- South tropical zone
- Great red spot
- South equatorial belt
- Equatorial zone
- North equatorial belt
- North tropical zone
- North temperate belt
- North polar region
One other way to be certain that it is Jupiter is by seeing whether or not it has 4 pinpricks of light surrounding it, either all on one side or surrounding the star at different variations. If you can see that, then these are likely to be Jupiter’s Galilean moons, which we’ll study in more detail below.
Now that you’re fairly sure that you have Jupiter in your sights, you’ll want to study the distinctive features of this unique planet. Well, to give you a little helping hand, we’ll outline some of them for you to give you an idea of what to look out for.
The Three Targets
There are 3 main targets that you’ll be looking to spot in and around Jupiter through your telescope or binoculars. The first one being the moons that surround the planet, the largest of which are bigger than some planets in our solar system.
These are the Galilean moons, of which there are 4 and they can be seen orbiting the red giant. These can be witnessed with even the most modern of telescopes.
Then you’ll want to turn your attention to the planet itself, mainly the gas bands that surround the surface and the infamous red spot. These details will be much easier to observe against dark skies with larger objective lenses.
Target 1: The Galilean Moons
There are 4 Galilean moons in total, being Io, Europa, Ganymede and Callisto, each one of them being larger than the dwarf planet Pluto on the outer reaches of the solar system. This is why we can see them a lot more clearly than Pluto.
The reason they are named the Galilean planets is that they were even spotted by Galileo during the first observations of the planet, way back in 1610.
Each planet orbits Jupiter at different speeds and distances. Below is a list of the cycles of each of the moons, starting with the one closest to Jupiter:
- Io - the closest planet to Jupiter, this takes 42 hours to orbit
- Europa - second closest to Jupiter, this takes 3.5 days to orbit
- Ganymede - third closest to Jupiter, takes 7.2 days to orbit
- Callisto - fourth closest to Jupiter, takes 16.7 days to orbit
You might find it difficult to observe these planets with a smaller scope, so you’ll want to invest in something more expensive with a decent eyepiece that can pick up what will appear as tiny pinpricks of light around the main reddish orb.
Checking back every few days, or even hours in the case of Io, you should be able to see the fluctuations in the moon’s relative positions. A lot of serious planetary observers enjoy watching the various fluctuations and transits of the moons as they disappear behind Jupiter.
If your telescope is really good, you can also see the ‘shadow crossings’, where the shadow of the moons can be seen on the surface of the planet.
Target 2: The Bands Of Jupiter
Once you’ve finished with the moons, it’s time to zone in on the planet itself, starting with the famous gas bands that surround the planet. These beautifully colored cloud bands are caused by the turbulence in Jupiter’s atmosphere.
There are 15 bands and zones that have been categorized by scientists, although not all of them will be visible from your home scope. The dark areas are called bands, whereas the lighter areas are referred to as zones.
Having a smaller sized eyepiece will give you the best chance of discerning Jupiter’s surface. For example, a 10mm sized eyepiece will give you increased visibility over a 20mm eyepiece.
By making these changes to your telescope, you’ll be able to find the right balance between the magnification and the image quality.
The unfortunate thing about a lot of eyepieces is that you lose image quality as magnification increases, which isn’t helpful if you’re trying to get a clear view of the planet.
On the most basic telescope, you should be able to make out the lighter equatorial zone, as well as the north and south equatorial bands. You might also be able to observe the polar regions.
Target 3: The Great Red Spot
This is one of the more challenging objects for you to observe, especially with a poor-quality telescope. Again, you will have to find the balance between magnification and image quality.
Even though the storm is larger than Earth, you’re still trying to spy against the monstrous and bright background of Jupiter’s surface.
To see the Great Red Spot, you’ll definitely need to have plenty of darkness as your backdrop, so we would recommend trying to see it when Jupiter is at its greatest elongation, that is, as far away from the sun as possible.
You’ll need at least 100x magnification to be able to see the Great Red Spot, making sure that Jupiter is in full opposition to the sun and that it’s as illuminated as possible. This year, Jupiter will be in opposition during August 2021.
To maximize the visibility of the spot even further, we would recommend that you use a green filter, as this will make the spot seem a lot darker.
Remember: rest your eyes every few minutes to prevent them from being strained, as this will give you the best chance of seeing the Great Red Spot rather than the spots appearing in your eyes.