Jupiter is well named, and is the largest and most dominant planet in the Solar System. It is actually a gas giant, of which its constituents are not well understood. But we do know that Jupiter is large, and heavy, being made up of more mass than all the other planets in the solar system combined. For these reasons, and to find out more about the internal composition of Jupiter, scientists are yearning to learn more about the hidden core of the massive planet.
A mission to explore Jupiter up close
In order to explore more closely than ever before, NASA dispatched an interplanetary exploration mission in 2011, led by an unmanned spacecraft called Juno. This will be the first time a space mission has explored Jupiter in more than 10 years. If you are old enough, you might remember that the Galileo spacecraft was launched in 1989, and orbited Jupiter for eight years.
What is different this time is that Juno will be fly much closer to the surface of Jupiter, in fact less than 5000 kilometers from the gaseous planet, which will be risky in itself. Last time, the Galileo spacecraft approached no closer than hundreds of thousands of kilometers in order to avoid getting wiped out by the stormy conditions at the surface of the gas clouds.
Well the good news is – Juno made it safely into orbit around Jupiter, and is on station and ready to start exploring Jupiter like never before!
What do we already know about Jupiter?
Jupiter is a massive gaseous planet, comprised mainly of hydrogen and helium gases. Scientists believe it was probably the first planet which formed as part of our solar system, after the Sun, which is also a massive and dense ball of hydrogen and helium gases. By comparison with Earth, Jupiter is eleven times larger than Earth, which doesn’t sound much, but when you consider the enormous gravitational pull, and the density of the gases, Jupiter is more than 300 times more massive than the Earth!
You can see Jupiter up close with a telescope!
Jupiter has long fascinated scientists on Earth, and even with a modest telescope, you can study the massive planet for yourself. If you are lucky, you might even see the most obvious feature of the gaseous planet which is known to astronomers as the Great Red Spot.
This colorful feature is actually a swirling storm in the atmospheric clouds of Jupiter, and the reason it is so well documented by scientists is that it is actually larger than Earth itself! The massive cyclonic storm has lasted for hundreds of years, and has been the subject of scientific study since the birth of astronomy.
What has surprised scientists is that the Great Red Spot has been losing its greatness, as the storm has been gradually receding, and the red spot has been visibly shrinking, even from our vantage point many miles away on Earth. The red spot was originally estimated at more than 41,000 kilometers across by astronomers in the 19th century. When more accurate instruments were employed to measure the red spot more recently, it was found to be only approximately 16,000 kilometers wide.
Juno has arrived at Jupiter!
The aim of the most recent interplanetary mission is for Juno to investigate the mystery of the disappearing red spot. One of Juno’s missions will be to explore how deep the red spot extends into the atmosphere of Jupiter, and this will better explain the nature of the swirling gaseous atmosphere. Deeper down, scientists would love to know what is at the core of the massive planet, as well as how much water exists on Jupiter, if any, and what other secrets are hidden behind those incredible swirling clouds.
Although the mission has taken many years to come to fruition, the last and most important phase of the space flight was the most risky, and there was virtually nothing anyone could do to prevent a disaster.
Juno will have a limited time in which to record data, and has a life span in orbit of just under 2 years. But before it can start recording data, it must first negotiate the tricky and largely unknown radiation belt around Jupiter. To do that, the spacecraft had to decelerate from its cruising speed of around 30 kilometers per second, and allow itself to be captured by the gravitational pull of Jupiter, but not so much that it succumbed entirely. The aim was for Juno to get close enough to allow scientists to collect as much data as possible, and fortunately, Juno has settled into a stable orbit close to the outer atmosphere of the mighty Jupiter.
Scientists hope to gather information about the chemical composition of the atmosphere of Jupiter by measuring the elements that make up the clouds. They hope to take measurements below the clouds mass using microwaves to explore beneath the visible surface. And they also plan to take measurements of the core of the planet via the gravitational pull on the orbit of the spacecraft.
All of these things can be measured below the surface, but scientists also hope to be able to see close up what the weather looks like around the outside of the planet, and this is where Juno is expected to provide excellent images of Jupiter that have never been seen before.
There are more than just clouds to look at. Just like on Earth, Jupiter has aurora lights that light up the polar regions of the planet. Scientists plan to use the sensors on Juno to measure the chemical ionosphere around Jupiter, in order to better understand the chemical makeup of our giant planetary neighbor.
If we can begin to understand the composition of the atmosphere of Jupiter, we can learn much more about the composition of the entire planet. If we can learn more about Jupiter, we can learn more about the entire Solar System
That is a job for Juno!
But in the meantime, if you would like to take a peek at Jupiter, you might like to take a look through one of our recommended best telescopes – click here to read our reviews on the best telescopes.
