Juno Arrives To Check On Jupiter's Affairs

SciWorks Radio is a production of 88.5 WFDD and SciWorks, the Science Center and Environmental Park of Forsyth County, located in Winston-Salem. Follow Shawn on Twitter @SCIFitz.

Jupiter: Roman God of the Sky and Thunder, king of the gods, and the name given to the largest planet in our solar system. It's a planet so large that, not including the sun, the rest of the solar system would fit inside with plenty of room to spare.

Jupiter's moons are named after the god's many lovers. According to mythology, when Jupiter thought his wife suspected him of cheating, he turned himself into a cloud to cover his affairs.

Now, NASA has sent the Juno Spacecraft, named after Jupiter's wife, to discover just what Jupiter has hidden beneath its clouds.

To learn more, Shawn spoke with Jonathan Ward, Volunteer NASA JPL Solar System Ambassador, and author of two new books about NASA's Apollo missions.

Jupiter in itself, and Saturn, as the two biggest objects in the solar system, other than the sun, are very important in terms of how the rest of the solar system formed. In fact, Earth's orbit and the orbits of the other rocky planets are more closely aligned with Jupiter's orbit than they are with the Sun's rotational axis.

Jupiter is extremely important. It helped shape our solar system!

We think that Jupiter and Saturn probably swept the solar system clear of other objects, and, in the process of moving outward from the sun, probably caused a lot of cataclysms that created the moon and really caused a lot of havoc in the solar system.

With a mission to expose Jupiter's secrets, Juno was launched in August 2011 and arrived at Jupiter this year on the 4th of July. It will take several months to position itself and start sending data. When it does, it should help solve our solar system's deepest mysteries.

One of the things that we really are most interested in trying to find out is how Jupiter formed. There are two competing theories about the gas giants: did they form close to the sun and then migrate outward, or did they form out in the outer solar system, migrate inward, and then migrate back outward again? And so Juno is going to help us determine the composition of Jupiter and its internal structure so we can kind of figure out exactly how the solar system formed.

There are five things that we want the Juno mission to be able to do, and that's to determine if

Jupiter has a central core, first of all. We think that there's a rocky core, somewhere deep inside Jupiter that's surrounded by a layer of liquid metallic hydrogen, but we're not really sure. Juno will help us nail that down.

We want to determine how much water and oxygen are in Jupiter's atmosphere, and that will help us determine whether Jupiter was formed farther out or closer in.

They want to see if the winds that we see at Jupiter are just in the atmosphere or if they go farther down into the interior of the planet.

Jupiter has one of the most intense radiation and magnetic fields that you can imagine. The magnetosphere goes out several million miles in the direction towards the sun and goes almost all the way out to the orbit of Saturn; so it's very, very powerful and an interesting thing for us to study.

One of the reasons it's important to understand the magnetosphere of Jupiter is that it will help us tell what the internal structure of the planet looks like. We can only see the cloud deck, which is about 30 miles thick, and Jupiter is much, much bigger than that; but the magnetosphere will tell us how the inside is structured.

Like anything from Earth, Juno may carry microscopic “passengers,” and, because of that, the spaceship will deliberately meet a fiery end.  

We still don't know whether Jupiter's moons could potentially support life. There's a subterranean ocean on Europa, and it could be a place that could harbor life. We don't want to risk crashing a probe that might have some terrestrial bacteria on it into a place that could harbor life so they're going to send Juno re-entering into Jupiter's atmosphere at the end of its mission so that it doesn't crash into one of those moons later on.