Jupiter and all its moons – A Guide to Use Reflective Telescope

Jupiter having the reputation of being the fourth brightest object in the sky is visible to the naked eye. It shines so brightly that its brightness even puts Venus in the background.

Just like the other planets, such as Mercury, Venus, and Mars – its discovery goes way back in the past. However, Galileo Galilei first observed it using a telescope. Hence, from the astronomical point of view, it was first observed in the early 1600.

Formation of Jupiter

If we consider the universe, there are far more galaxies than the Milky way itself. Many other planetary systems are in existence. There are specific hypotheses that the formation of Jupiter happened even before the Sun itself. Gravity attracted gas and dust from around and created Jupiter some 4 billion years ago.

The distance of Jupiter from Sun

Position-wise, it is the fifth planet from the Sun. It has an average distance of 5.2 AU from the Sun. However, Jupiter’s closest point to the Sun is at 4.9 AU, and the farthest is at 5.4 AU.
On a good note, you can check Jupiter’s position via the internet as its tracking is pretty accurate.

Size of Jupiter

Jupiter is a huge planet in our Solar system. It has a radius of approximately 69.91 kilometers – hence 11 times bigger than the Earth itself.

Mass of Jupiter

Jupiter is almost 2.5 times bigger than all the planets combined! It is approximately 318 times heavier than the Earth, carrying the volume of about 1,321 Earths. Massive, isn’t it?

Jupiter’s Rotation with Reference to Sun

A day on Jupiter is almost 10 hours – it means that Jupiter rotates once after every 10 hours or so. The 10 hours time makes it a planet with the shortest day in the Solar system.
However, a Jupiter year is equal to 12 years on the Earth – which is quite long!

Structure of Jupiter

It is devoid of having a solid surface and comprises of gases and liquids such as hydrogen and helium – quite similar to the Sun. About 90% of its radius contains conducting plasma – identical to liquid mercury.


Jupiter has an enormous atmosphere in the whole Solar system – ranging up to 5000 kilometers in height. It stays covered in clouds formed of ammonia crystal and ammonium hydrosulfide.

The upper atmosphere comprises about 90% hydrogen and 10% helium. Some other elements, such as methane, water vapors, ammonia, silicon compounds, carbon, oxygen, ethane, etc. are also present in small quantities.

The outer atmosphere contains frozen ammonia crystals – with 70% hydrogen, 24% helium, and 5% other trace elements.


Jupiter’s magnetic field is fourteen times greater than Earth’s magnetic field because of its mass and density. Thus, Jupiter has the strongest magnetic field in the Solar System.
Because of its strong magnetic field, a plasma torus surrounds Jupiter, making it difficult for the spacecraft to reach the planet.

Temperatures on Jupiter

The temperature ranges from -145 degrees celsius to much higher temperatures. Sometimes, it gets even hotter than the Sun itself.

The Great Red Spot of Jupiter

The oval-shaped object that rotates in a counterclockwise direction around the planet in a period of six days – is referred to as the Great Red Spot. Ever since its discovery, it is decreasing in size, and a hypothesis reveals that it is falling in length by 930 kilometers every year.

Winds on Jupiter

Storms are prevalent on Jupiter – some small and short storms last for a couple of hours while others are long and may last for centuries. Winds blow at an average speed of 360 kilometers per hour on certain parts of the planet.

Moons of Jupiter

It has regular and irregular moons which have further subdivisions.
Regular Moons such as Lo, Europa, Callisto, Ganymede
Irregular moons that are smaller and have elliptical orbits. Although their exact numbers are unknown, they have a few subdivision such as:

  • The Himalia group which is a clustered group of moons
  • The Ananke group with a retrograde orbit with rather indistinct borders
  • The Carme group with legally distinct retrograde orbits
  • The Pasiphae group has a very dispersed and only vaguely particular retrograde group covering all the outermost moons.

Three irregular moons that do not fall under these subdivisions are:

  • Themisto, which orbits between the Galilean moons and the Himalia group.
  • Carpo at the inner edge of the Ananke group and orbits Jupiter
  • Valetudo, which has a prograde rotation but overlaps the retrograde groups.

Rings of Jupiter

The Ring system comprises of three segments mainly:

  • Inner Torus, also known as the Halo
  • A brighter main ring
  • An Outer gossamer ring

Possibility of Life on the Planet

Since it does not have a true and solid surface but swirling fluids and gases, it is not sustainable for life. The Moons of Jupiter, such as Ganymede, Callisto, and Europa, on the other hand, have better chances of inhabiting life.

How Does Jupiter Show through a Telescope

As soon as you find it, you will see a glimpse of light in your eyepiece. From the eyepiece of a reflective telescope will catch a glimpse of light in your eyepiece. From the eyepiece of a reflective telescope, you will see a disc-shaped Jupiter. You can focus the planet-by adjusting the focuser of the telescope.

The Verdict:

A spacecraft that we call Juno was launched in 2011. These missions are coming up with ways to determine the possibility of life on the planet Jupiter. By using a high-resolution reflective telescope, you can easily see the planet and its moons. In a telescope eyepiece, you’ll see bands on the surface of it. If you see something like this, you should know that Jupiter is shining brightly in the sky. It is one of the most fascinating things that we wish to look up in the sky. So, best of luck on your sky journey! It will definitely be a mesmerizing one.