Hi, I'm Trish, Programs Coordinator at the Space Centre

When we talk about space and the universe, we tend to picture things on a colossal scale. A scale that challenges our brains as we try to understand just how far away planets are from one another and how large they are compared to Earth. One of the questions about the scale of things in our solar system that we get from young visitors to the Space Centre is about how big these giant planets are.

The gas and ice giants come by their name honestly: they “are” giants. There are four giants in our solar system, Jupiter, Saturn, Uranus and Neptune. They are really big planets: we could fit 1,321 Earths into Jupiter, 764 Earths into Saturn and 63 Earths into Uranus and Neptune.

However, their name not only describes their size, it also refers to their composition or materials that make up the planets. Gas giants, Jupiter and Saturn, are mostly made up of hydrogen and helium and are sometimes referred to as failed stars because they are made of similar material. Neptune and Uranus are classified as ice giants, because they have more ice-forming elements such as oxygen and carbon, and much colder atmospheres, the coldest atmospheres in our solar system.
 
Scientists have lots of questions about these giant planets and are using a combination of spacecraft and telescopes to study them. In 2011, NASA launched the Juno spacecraft to study Jupiter. Just this past May, Juno and the Hubble Space Telescope joined forces to look deeper into Jupiter’s atmosphere and discovered that the planet has huge lightning storms with thunderheads measuring over 64 kms tall. Juno will continue to study Jupiter until July 2021, providing scientists with information to help understand its origin and how much water is in its atmosphere. Knowing more about Jupiter better will help scientist better understand how these gassy giants formed and the role they played in how our solar system formed.

Saturn, the second biggest giant in our solar system is best known for its famous reflective rings.  NASA’s Cassini spacecraft spent over 20 years investigating Saturn and its icy moons. Cassini gave us stunning pictures of and insights into Saturn’s properties, such as what is beneath its atmosphere; certainly not solid ground! If a spacecraft attempted to touch down on Saturn, it would never find anything to land on.

The only probe that has flown by Neptune and Uranus is Voyager 2. We think of Neptune and Uranus almost as twins because they are similar in size and have a bluish green colour caused by the methane in their atmospheres. Scientists have been using telescopes such as the Hubble Space Telescope to study these distant giants and they have proposed to launch probes to these distant icy giants in the 2030s.

What does the future hold for our understanding of these giants?  Scientists are always looking for opportunities to dig deeper and understand the science collected by both satellite probes and earth-based observations.  What’s next? After Juno and Cassini, the next exciting missions to Jupiter are proposed to launch in 2022. The Europa Clipper mission will explore Jupiter’s moon Europa and the ocean of liquid water beneath Europa’s icy crust. The European Space Association will launch a satellite called JUICE which will explore Jupiter’s atmosphere and magnetic environment. It is really just beginning of exploration to the outer reaches of our solar system.

We’ve pulled together a playlist of learning resources to guide you on your exploration of each of the giant planets in our solar system. Have Fun!

 

Junior Astronomer Playlist (kids 8-12)
TimeActivity
10mins.

Let’s go on a mission to explore the gas giant planets! Our first stop is Jupiter, the largest planet in our solar system. Watch this video to discover what it would be like to fall into Jupiter.

A trip to Jupiter wouldn’t be complete without visiting its famous Great Red Spot. Discover more about this super storm that has been brewing on Jupiter’s surface for at least three centuries.

Even though no humans have been to Jupiter, a spacecraft called Juno has! Learn more about Juno here.

Ask yourself: What do you think the solar system would be like if Jupiter didn’t exist?

25mins.+

Our next stop is Saturn. Watch this video [link - https://www.youtube.com/watch?v=8SgtXNftOEM] to soar through its magnificent rings.

Make your own model Saturn with a CD, then discover more about Saturn’s rings and the Cassini spacecraft NASA launched to study them.

Ask yourself: Are Saturn’s rings solid like the CD you used to make your model?

10mins.

Next up is Uranus. Watch this video to soar through this strange, icy giant that rotates on its side as it orbits the Sun.

Investigate why Uranus orbits the Sun on its side.

Ask yourself: Which of Uranus’ characteristics do you find the most interesting?

10mins.

Our last stop is Neptune, the eighth and most distant planet in the solar system. Watch this video to journey to the centre of this cold, windy giant.

NASA thinks it may be time to visit Neptune again to unravel the mysterious surrounding its moon Triton. Find out about its unusual orbit and why its surface looks like the outside of a cantaloupe!

Ask yourself: What would you want to study if you were commanding a mission to Neptune?

15mins.

 

Even though we can’t really set foot on the gas giants, we can still observe them from here on Earth. The end of this month is a great time to see Jupiter and Saturn posing with the Moon after sunset. Check out these skywatching tips from NASA to look for the planetary pair in the night sky.

Ask yourself: Which of the gas giants are you curious to learn more about?

Senior Astronomer Playlist (teens 13-15/adults)
TimeActivity
20mins.

Let’s go on a mission to explore the gas giant planets! Our first stop is Jupiter, the largest planet in our solar system. Watch this video to discover what it would be like to fall into Jupiter.

Read about the top 10 discoveries Juno has made about Jupiter. 

Ask yourself: Which of Juno’s discoveries so far do you think is the most significant?

30mins.

Our next stop is Saturn. Watch this video to soar through its magnificent rings.

Discover more about NASA’s Cassini spacecraft whose mission to Saturn revealed new insights about and this gas giant’s magnetosphere, rings, and family of moons.

Ask yourself: Why do you think Cassini had to end its mission in a plunge into Saturn’s atmosphere?

15mins.

Next up is Uranus. Watch this video to travel to this strange planet that rotates on its side as it orbits the Sun.

Investigate three mysteries scientists have yet to solve about this icy giant’s extreme tilt, its unusually tortured moon Miranda, and its dusty rings. 

Ask yourself: Which mysteries about Uranus intrigue you the most?

10mins.

Our last stop is Neptune, the eighth and most distant planet in the solar system. Watch this video to journey to the centre of this cold, windy giant.

NASA thinks it may be time to visit Neptune again to unravel the mysterious surrounding its moon Triton, the only large moon in our solar system that orbits in the opposite direction of its planet's rotation. Read about the proposed Trident mission here.

Ask yourself: Where else do you think we should explore in our solar system?

15mins.

 

Even though we can’t really set foot on the gas giants, we can still observe them from here on Earth. The end of this month is a great time to see Jupiter and Saturn posing with the Moon after sunset. Check out these skywatching tips from NASA to look for the planetary pair in the night sky.

Ask yourself: Which of the gas giants are you curious to learn more about?