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BY JOVE!
DECEMBER 8, 1995
TRANSCRIPT
Jeffrey Kaye of KCET-Los Angeles has a report on the Jupiter mission of the spaceship Galileo.
JEFFREY KAYE: Today, scientists at the jet propulsion laboratory in Pasadena prepared to receive data expected to arrive from Jupiter Sunday morning. Yesterday, to the delight of project scientists, a capsule from the spacecraft Galileo successfully sped into Jupiter's atmosphere to probe the largest planet in the solar system. The rendezvous began the final act of a six-year, 2.3 billion mile drama. The 2 1/2 ton Galileo was launched in 1989 from the space shuttle Atlantis. En route to Jupiter, it looped twice around the Earth and once around Venus, using the gravity of those planets to boost its own energy. A major setback came in 1991, when the spacecraft's main antenna failed to open properly. Scientists worked around the problem, and Galileo was able to send back images of asteroids and a comet. In July, Galileo detached its companion capsule, and yesterday, after the probe sped into Jupiter's atmosphere, it dropped by parachute for 125 miles. Before it melted in extreme heat, its instruments measured the weather, took chemical readings, and sent back the data to the orbiting Galileo. The $1 1/2 billion spacecraft is supposed to orbit Jupiter 11 times in the next 22 months. Jupiter is a windy, gaseous stew, with powerful magnetic and radioactive fields. The planet is orbited by an estimated 16 moons, in all a system that is a potential treasure trove for scientists researching the origins of life. Dr. Ed Stone is director of the Jet Propulsion Lab. Thank you very much for joining us, Dr. Stone. This is a full-scale mock-up of Galileo.
EDWARD STONE, Jet Propulsion Lab: Yes.
JEFFREY KAYE: Correct?
EDWARD STONE: Yes, it is.
JEFFREY KAYE: What exactly are we seeing here?
EDWARD STONE: Well, the bulk of the spacecraft, of course, is the large antenna up at the top which was originally intended to return the data to Earth--
JEFFREY KAYE: Right.
EDWARD STONE: --but did not unfold. The ridge you see did not all unfold, and so we're returning the data at a much lower rate on a small antenna. The large central section is all the fuel which we used to put ourselves into orbit, and which we will use to steer ourselves through the successive encounters that we have ahead over the next two years.
JEFFREY KAYE: Now this is essentially the guts of the laboratory, right?
EDWARD STONE: These are the instruments which are on a platform which allow us to look at Jupiter and at the moons of Jupiter and at the rings, so there's a camera on this platform, there's an infrared and an ultraviolet spectrometer, and another instrument to measure the polarization of light. So those can be aimed at whatever object we're flying by for the very highest resolution images and other scientific data we've already gotten.
JEFFREY KAYE: Where's the camera?
EDWARD STONE: This is the camera, and we will be seeing things 10 meters across on the surface of the moons as we fly by them, taking pictures.
JEFFREY KAYE: Color pictures?
EDWARD STONE: Color pictures, yes.
JEFFREY KAYE: Which we'll see when?
EDWARD STONE: The first of those will come back in July, because our first encounter is with Ganymede at the end of June in 1996. And then every two months or so thereafter, we'll have another encounter with a new set of data coming back from that moon.
JEFFREY KAYE: What's this?
EDWARD STONE: This is to detect the dust which we've already seen streams of dust, very tiny dust particles coming from Jupiter. We know Jupiter has a ring. We know that IO has all the volcanic activity. We don't know yet for sure what the origin of the dust is, but we will be studying the distribution of dust in the Jovian System as we fly through this immense magnetic field that surrounds the planet.
JEFFREY KAYE: And as we continue our tour, what is this immense thing sticking out?
EDWARD STONE: This is a boom which was deployed after launch. It's made of fishing rod material to hold the magnetometer to measure that planet's magnetic field and to measure the radio waves that are generated by this immense magnetic field and by the plasma which is trapped in that magnetic field.
JEFFREY KAYE: So what will be Galileo's fate after its two-year-long mission?
EDWARD STONE: Galileo is now a new moon of Jupiter.
KAYE: And will be?
EDWARD STONE: And will be.
JEFFREY KAYE: Forever?
EDWARD STONE: Forever.
JEFFREY KAYE: What are you hoping to learn about Jupiter?
EDWARD STONE: We'd like to know what Jupiter is made of. It's the largest planet in the solar system and can tell us a lot about the materials out of which the entire solar system is formed. So the main purpose of the probe dropping into the atmosphere yesterday was to measure directly for the first time, below all the cloud levels, what the composition is of the molecules, the gas which make up this giant planet.
JEFFREY KAYE: And for the next couple of years?
EDWARD STONE: For the next couple of years, the Orbiter will be touring the Jovian system, exploring the giant magnetic field, which is the largest structure in the solar system, and flying hundreds of times closer to the moons of Jupiter than Voyager did in 1979.
JEFFREY KAYE: Now, the moons are extraordinarily varied, right?
EDWARD STONE: That's what, of course, Voyager showed us is how diverse these worlds are, even though in many ways they're fundamentally the same kind of bodies: IO with its many volcanoes being tidally heated by Jupiter's great gravitational field, Europa; which is a little further away and has a thin ice crust which is the smoothest surface we've found in the solar system, so smooth that we think it may well be ice-packed on a liquid water ocean. If that's the case and there is, indeed, another liquid water ocean in the solar system today, that's got to be an object of future exploration.
JEFFREY KAYE: Now, on Europa, you think that that ocean, if there is an ocean, might actually contain life or rudimentary forms of life?
EDWARD STONE: Well, once you have--we know how important the ocean was to the origin and evolution of life here on Earth, and we have now discovered that there are life forms under our ocean which don't depend on sunlight at all. So that suggestion is if there is a liquid water ocean, then that certainly raises the possibility that there might be some sort of life form in that ocean. So the next stage of the exploration that Galileo is going to reveal to us, about a year from now, when it has its first fly-by of Europa in December of 1996, is, does this look like an ice pack on a liquid water ocean? We'll be image things about 10 meters across in size. And if we do believe that it looks like that's the case, then I think we'll in the future want to focus on getting down to the surface of Europa and, of course, eventually through that icy crust.
JEFFREY KAYE: What's been the mood about here? It must have been one of tremendous feeling of accomplishment.
EDWARD STONE: Great elation, of course, because the--the project has had a lot of difficulties, and each time we found a way to work around some very serious setbacks, and, of course, now we're there, the probe has sent back its data to the spacecraft. The spacecraft is in orbit, and we have two years at least of wonderful discovery ahead of us.
JEFFREY KAYE: Well, congratulations, and thank you very much for joining us.
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