Enjoy the first installment of the mini-podcast about past, present and future space missions just in time for JUNO’s arrival at Jupiter!
In this episode we talk to Planetary Society’s Senior Editor and Planetary Evangelist, Emily Lakdawalla about JUNO’s camera and citizen science. We also share some fun facts about Jupiter and other spacecraft that have studied the gas giant in the past.
Image and Information Courtesy of NASA
- When I say “Humans have visited the planet before” I mean human-made spacecraft not actual humans like in Interstellar
- There is a water “whooshing” sound in the show because I interviewed Emily at Lakewood in Bellingham, WA. It was very scenic.
Click Here for Transcript
[♪ Gershon Kingsley playing Popcorn ♪]
Dr. Regina Barber DeGraaff: Hi. I’m Regina Barber DeGraaff. I’m an astrophysicist and TV/movie lover. I am also the host of Spark Science and this is our first episode of the mini-podcast: “Spacecraft Chronicles,” where we share knowledge of past, present, and future space missions.
Today we’ll talk about NASA’s JUNO mission to Jupiter and play an interview with famed science blogger and planetary society’s senior editor and planetary evangelist: Emily Lakdawalla. JUNO launched on my birthday and will arrive to Jupiter on another famous birthday: the 4th of July. My sister heard Emily Lakdawalla days before this interview and claimed she suddenly felt she could relate to me and science. My sister is a lawyer.
JUNO arriving on the 4th of July gave my sister thoughts and flashbacks of the film: Independence Day. And it’s fine; anything to get my sister into science is great. However, let’s listen to the audio of JUNO mission’s trailer made by NASA’s Jet Propulsion Lab to understand why my sister would make this connection.
[Rumbling.] [♪ Ominous music ♪]
Speaker: The scariest thing to me about JUNO are the unknowns. So much about the environment that we’ll have to withstand is unknown.
[Ominous sound effects.]
Nothing is really certain about what’s going to happen.
Speaker: It’s a monster. It’s unforgiving. It’s relentless. It’s spinning around so fast. It’s gravity. It’s like a giant sling-shot slinging rocks, dust, electrons, whole comets. Anything that gets close to it becomes its weapon.
It just so happens, deep inside this body are the secrets we’re after; secrets about our early solar system.
Speaker: It’s the biggest and baddest planet in the solar system and it’s got the biggest and baddest radiation and the biggest and baddest magnetic field.
Speaker: The background radiation that we’re exposed to on Earth is about a third of a rad. What we expect to see at Jupiter is about 20 million rad. No spacecraft has ever flown this close to Jupiter, flown this deep into the radiation belts.
Speaker: The real trick is: we’re gonna go in close, get the data, and get out. And the first time we go in, that’s the most dangerous. We call it “Jupiter Orbit Insertion” – J.O.I.
Speaker: Nothing is really certain about what’s going to happen.
Dr. DeGraaff: So we just heard this intense trailer about the JUNO mission. And please, please, if you have time, go watch the video trailer. It’s posted on the Spark Science Twitter and Facebook account. Because the video is just as intense as the audio.
However, enough with hype. Let’s get to the science and some fun facts. Fun fact #1. First of all, it might surprise some that JUNO is not an acronym like most science projects. Many of you know that NASA and many astronomers are very excited about making acronyms. One of them is SLoWPoKES. That stands for “Sloan Low-mass Wide Pairs of Kinematically Equivalent Stars.” Yeah. And some of the acronyms are actually long words like SAGITTARIUS, which actually stands for, get ready for this: Space-borne Astronomical Gravitational-wave Interferometer To Test Aspects of Relativity and Investigate Unknown Sources.
Some of these acronyms have acronyms inside of them, like VIDEO, which is VISTA Deep Extra-galactic Observations. And “VISTA” stands for Visible and Infrared Survey Telescope for Astronomy. Ugh! But anyway, it’s good to know that Juno is actually the name of the wife of Jupiter. And if you have some knowledge of Roman mythology, this makes complete sense, and you also know that she was thought to be able to see through clouds. And since Jupiter is a gas giant – and now I’m talking about the planet, not the Roman god – it has many clouds and massive storms. So this mission is aptly named.
Fun fact #2. Many of you know that Jupiter is the second-largest object in the solar system, the sun being the largest. But you may not know that it has the largest ocean. Now scientists believe that deep in the atmosphere, the pressure and the temperature is so great that it compresses hydrogen gas into liquid, which gives Jupiter the largest ocean in the solar system. That ocean is made out of hydrogen instead of water.
Fun fact #3. So many moons! Jupiter has fifty (50) confirmed moons and 17 unconfirmed moons. What are these unconfirmed moons? They could be asteroids. They could be other things that aren’t necessarily associated with Jupiter’s gravitational pull. Also, the 4 famous moons of Jupiter were discovered by Galileo in 1610: Io, Europa, Ganymede, and Callisto. But don’t worry; we will be talking about missions to these moons in the future, but not in this podcast.
Fun fact #4. Jupiter has rings. One of the first fly-by missions to Jupiter (Voyager 1 in 1979) actually found and surprised many scientists that Jupiter had small rings.
Fun fact #5 to #12. Jupiter has been visited by humans before. There’s been 5 missions that have studied and captured images of Jupiter as we flew by the planet: Pioneer 10 and 11 and Voyager that we mentioned before in the 70s. Ulysses in the early 90s. Cassini in the year 2000. And the most recent fly-by was the famous spacecraft whose mission was to return revolutionary images and data about Pluto: the “New Horizons” spacecraft. And that flew by Jupiter in 2007.
However, orbiter missions are different in that they can study the planet more thoroughly, like the Galileo spacecraft did in 1995. This was the first time Jupiter’s atmosphere was directly explored. JUNO will be another orbiter that will brave the harsh environment of the massive gas giant. JUNO hopes to examine Jupiter’s chemistry, atmosphere, interior structure, and magnetosphere. And it’ll be the first time we see below the dense clouds. Let’s let Emily Lakdawalla, the great science communicator, tell us more.
Emily: Yeah, so the JUNO mission is a Jupiter orbiter that is designed to study the deep interior of a planet. And you should already have a question about that, which is: how do we study something that we can’t possibly see or directly sense?
Dr. DeGraaff: Right.
Emily: So, there’s a few different ways that JUNO is designed to do that. JUNO is gonna look at the gravity field of the planet by orbiting close to it and far from it while sending a radio signal to Earth, and we can tell from the Doppler shift of the signal what the shape of the gravity field is. We’ll be able to see if there’s mass concentrated toward the center or not.
So, that’s one thing, so gravity is one thing. Another is these microwave sensors, which are looking at longer wavelengths than light, and you can use those to look down to – I forget how many kilometers – but some depth into the atmosphere, so you can see all these different cloud levels, which is gonna be pretty interesting. And then there are several instruments that look at the magnetic field, which probably arises from something happening pretty deep inside Jupiter.
Dr. DeGraaff: Right, which we wanna know about.
Emily: Yeah. We wanna know about that.
Dr. DeGraaff: Yeah.
Emily: And then they’re gonna look at the aurorae, which have to do with the magnetic field.
Dr. DeGraaff: Pshhh! It’s gonna be so amazing!
Emily: Yeah. Now we can see those from Earth. We’ve seen aurorae with Hubble, which is actually pretty awesome. But we’ll be a lot closer with JUNO, and so that’ll be pretty cool.
Dr. DeGraaff: That’s amazing. So, this is before July 4th, so we’re assuming everything went great.
Dr. DeGraaff: And how long is the mission and what else is it… is it just gonna focus on Jupiter?
Emily: Sure, so, JUNO is a relatively short mission. And the main reason for that is that Jupiter’s radiation environment is really nasty. It is horrible. And in order to understand the deep interior stuff, you have to get quite close to Jupiter, which means you’re very deep into its really nasty radiation environment. So that means our spacecraft is going to have a very short life. So, what they’re doing to mitigate that is that JUNO has a polar orbit; it goes up and over the north pole and then down across the equator and across the south pole in its orbit.
Dr. DeGraaff: Oh, wow!
Emily: And the shape of that orbit is chosen because Jupiter’s magnetic field is shaped like a donut that is centered on the equator. And so Jupiter is going through the hole of the donut, avoiding the worst part of the magnetic field. But over time, the orbit is gonna change shape. It’s gonna start dragging down into the magnetic field, so the environment for JUNO is gonna get worse and worse and worse. And they’re sure the spacecraft is going to die in 2018, so they’re actually planning to deliberately impact JUNO into Jupiter in February of 2018 so the mission is going to be pretty short.
Dr. DeGraaff: So we can get some data right before it starts exploding and dying.
Emily: Heh. It will be talking to Earth all the way down, which is pretty cool. So that will be cool. So that’s the scientific mission of JUNO is to study the deep interior of Jupiter and do all this stuff close in to the magnetic field. But everybody agreed that it would be a crime to send a spacecraft to Jupiter and not put a camera on it that could take pretty pictures.
Dr. DeGraaff: Yeah. Absolutely.
Emily: So they put on this camera called JUNO-Cam. It’s a very small camera. It’s actually derived from cameras that they used on the Mars Science Laboratory “Curiosity” Mission.
So I work for an organization called the Planetary Society and one of our founders was a geologist named Bruce Murray who argued vociferously that you could not send a spacecraft to Mars without a camera. And everybody said that “No. You don’t need a camera. It’s not gonna give us useful science. This is a science mission. We need science instruments.” And Bruce Murray pounded the table and said “No. We need a camera.” And the rest is history because, I mean, it told us so much about Mars.
It’s whole purpose is to engage the public. And so pretty pictures are what it does to engage the public. But there are several other things done around this camera that involve the public. To begin with, in order to know where to point the camera, we need to know what Jupiter looks like this week. And Jupiter changes pretty fast. Its clouds move a lot.
And so, in order to predict where we need to point the camera, we need to have a map of what Jupiter loo