Jupiter A Clearer Picture (1988)

during this program we are going to see beautiful pictures of the largest planet in our solar system Jupiter we will also see some of its 14 moon moons in surprising detail these pictures are better than the Pioneer spacecraft pictures of Jupiter we saw during the previous program I'm Mary Ross director of space programs at NASA's Lewis Research Center in Cleveland Ohio and I'm your host for this tenth program in our series of 13 called journey through the solar system [Music] now let's see a videotape made after the Voyager 1 spacecraft had its closest encounter with Jupiter in 1979 Rodney Mills of NASA describes the Voyager pictures this is an image of Jupiter we obtained from a distance of something like 50 million miles but we were immediately struck by the fact that it looks a lot different than it did when an earlier spacecraft the Pioneer flew by in about 1973 in 1974 the bands and the zones look different the appearance of the Great Red Spot looked different and a number of other features very dynamic it's a very dynamic place yes is it solid Jupiter may have a small solid core about the size of the earth but for the whole most part it's a it's a large bag of liquid and gas mostly hydrogen now we don't ever see the solid surface all we see are the cloud decks we don't know what gives them the color we have some suspicions and maybe some of our data will reveal that in the years ahead we have a mission that will take a satellite to Jupiter and penetrate these gases do we not that's right we have a mission on the books right now which will include a probe that will go down and penetrate into the surface and actually into this surface of the clouds and actually take some measurements that'll be exciting well I think this is one of the more beautiful of the motorgraph showing to the satellites passing in front of the planet now Jupiter has about 13 satellites or moons of these four of them are very large they're the ones which Galileo discovery discovered and in this photograph you can see two of those moons passing in front of between the spacecraft and the and Jupiter about the sizes of the satellites they like very large like they're large actually two of them are larger than the planet Mercury [Music] this four Galilean satellites are Eyal the one closest to the planet then comes Europa and Ganymede and Callisto two of those are larger than mercury three of them are larger than our own moon so they're all really planets in their own rights what we have out there Jupiter is really a miniature solar system we have a large body which is radiating more heat than it receives possibly of other summons it's a Sun that didn't quite make it right but and they and the density of these satellites varies considerably just like the densities of our own the premise very yes the ones closest to the central body are hard rocky objects and the ones further away are less dense this is a close-up view of shows a Great Red Spot this is a feature that to anyone who has a small telescope can possibly identify on Jupiter Galileo observed the Great Red Spot so we know it's been in existence something like 300 years now it moves around the planet a little bit but it never loses its identity completely and this is amazing considering it's really just a storm and that cloud formation that's large - as I recall the right size of three diameters of this as wide as the three diameters of Earth so it's a large storm now we were very interested in where the energy comes to make this thing exist and we were interested whether it was rotating or not and we have found that out we have found for instance that it rotates once every six days I should mention also that Jupiter has a lot of energy if it spins on its axis so that a day on Jupiter is only ten hours long aesthetically the photographs are beautiful let me show you some examples of the of the art beautiful art defy photography has come out of the mission so far this is a view of a portion of the planet Jupiter in its normal color now as an aid to trace the flow of the here we introduce some artificial coloring and it comes out very remarkable this is a an example we've been gonna learn a lot about the dynamics of motion and in the flow patterns in fact we photograph the planet Jupiter continuously over a period of a month with still flows and now we've assembled them into a movie all which we can run and and speed up the motion and you can actually see the flow of the atmosphere and the appearance and disappearance of clouds and our scientists are busily engaged in analyzing that certainly looks different than anything we've seen there than any other planets what else do you have here well before I leave it let me show you a spread out map of the entire planet Jupiter this is a new result that's just released this week this is the equivalent of a Mercator projection it shows all sides of Jupiter at one time and it's unusual in that most of us didn't realize how many various plumes and spots there are on the planet and all of these things move in the movie that I spoke about they all go at the different speeds relative yes they go in pack and tend to go in opposite direction so some of the band's flow one direction like eastward and some flow westward and lots of questions yes lots of questions and some of the dark spots we had seen in some of the white spots we had seen prior to that some of the white spots down in the southern latitudes have been observed for around 30 or 40 years I mentioned that the Great Red Spot has been observed for 300 years some of the features are appear in a matter of a few days or a few weeks and then they disappear yeah to go on there were several other features that I should mention about Jupiter we made a remarkable discovery and we found that there is a ring around Jupiter understand a right now we know that of course Saturn has these beautiful silvery rings and a short period time ago we found that Uranus has some thin rings and now Jupiter has joined the club so it leaves or without almost this illustrates where the camera was aimed we took a single exposure out in this area where the little square is located at the time we cross the equatorial plane Jupiter with a spacecraft and we took a single 10-minute exposure and I'll show you the resultant photograph this is a black-and-white photograph and it takes a little explanation these strange Wiggly marks up here are actually images of stars because the spacecraft was moving during the 10 minutes so the stars actually left a little jagged traces but in the central portion of the photograph you'll see these straight lines actually there are six separate images that's right yeah and that's the edge of the ring looking straight on at it yeah now the ring is very dark it's it's fairly thin probably not thicker than the 20 miles or something like that and it's composed we think of rocks and they're very dark well we'll be taking more images of this week Voyager 2 right and since we discovered it I believe there has been an observatory here on earth that has also confirmed the discovery this photograph of Jupiter has had a green drawn on it by an artist to give you some idea of the the size of the ring but although we know approximately its thickness we really don't know the extent of it inwards towards the planet and we will be measuring that with the next spacecraft are these rings always in the equatorial plane of the island right that's in fact the that's a requirement almost possibly something that never was quite formed into what it should have been an order or a delight or could be the broken up debris of a small satellite and that's probably likely there is another object that's fairly close to the planet Jupiter and this is a small satellite animal fee up it's really not one of the Galilean satellites but it's the innermost satellite and this had never been seen by mankind before as anything other than a point of light in fact very few astronomers had ever seen it it's a really a small rocky it's not spherical in shape it's a approximate sizes like 80 by 150 miles it's very dark very red and maybe just a captured asteroid traveling pretty rapidly probably to it we catch the closer to the planet as the spacecraft swung behind the planet Jupiter we took occasion to take some images of the dark side of the planet and we made another remarkable discovery this is a photograph that appears rather noisy but in fact it contains quite a bit of information this light arc across the top here is actually an Aurora display like the Northern Lights here on earth right atmospherics being excited by charged particles spiraling in then down lower in the photograph there are some bright white spots and we believe that's evidence of lightning lightning a blob of the cloud tops all right the same sort of thing is seen sometimes here on earth down in the tropical areas and they're called super bolts it's a great deal of energy and these measurements were later confirmed by our spacecraft we have a on the spacecraft an instrument to listen to the planet and we heard electrical waves of course binding to hustlers which are created by lightning what about some of the other satellites let me speak about the satellites not exactly in the order we observed them but the the outer most of the four large satellites is his Callisto Callisto is not very dense we know that it has a density that not about halfway between water and rocks so we know that it must be composed about half of ice throw there cold object it has no atmosphere this is a color photograph we obtained of Callisto as we flew by it and we were immediately struck by the fact it's heavily cratered probably more heavily than the moon is even and this is evidence that it's not changed much in the last four to six billion years you know atmosphere there's apparently an old volcanic action and it's it's staying stayed frozen it has rings or appearances right there is one large impact basin up there where it looks like some very large object had struck it and form concentric rings around the basin and those have been apparently frozen in the ice so it's and elsewhere you can see some small craters that are very light appearing it looks like the the dark covering on the planet has been thrown aside and it's exposing probably nicer ones or possibly you know operators well we think probably it was cratered at about the same time in history that the earth and the moon and Mercury were and that was back in way before our time probably four to six billion years ago that hasn't changed much since then this is another photograph in color of the entire planet Callisto actually it's a satellite but it really deserves to be considered as a as a planet and finally a third photograph of Callisto which shows in black and white a little more of the cratering details you can see has been impacted this pockmarked the wide range of sizes also if you notice along the limb or the outer edge of the satellite here you'll notice there isn't much relief apparently there are no mountains and that's consistent with a theory that there's a lot of ice in the in the in the satellite and it really couldn't support mountains next moving inward I'll talk a little about Ganymede which is probably one of our favorite satellites because it has such a diversity of appearance again here's a full image of the Ganymede you see it's a different color and has a different texture there are light areas and there are dark areas we think the dark areas are a little bit older and the light areas are a little more there's some evidence here that the surface has been under a lot of stress and it has been altered during the eons of time since it was formed a fair number of craters but not as minions on Callisto this would be dense not more dense than that we've seen before right well rock or rock but still an appreciable amount of ice and and water of course if it were warm enough but it is right this black and white photograph illustrates the the rough texture we see on portions of Ganymede this looks a little bit like some dune buggy's have been running around in the sand actually the scale is quite a bit larger and either the surface has been compressed or stretch or stretched and given rise to all these ridges and we have impacts as we see there yes so you can see that whenever that happened it was still before the end of the cratering action took place our geologists are having lots of fun with these images one more rather remarkable photograph here of an area showing both the light and dark surfaces and we have an example here of a fault line it's the only place besides the earth we've seen any evidence of earthquake fault lines I'll try to point it out down here you'll see a displacement down in this version of the lighter area where the move it's it's been mowing the left the hold right we've not seen this any other point or not on the moon on our mercury and a courtyard and not on Mars because we haven't seen an actual salt surface of Venus but but so far this is the only other place in the solar system now moving into the next satellite this is a image of your will pop now this is a walkie satellite this is actually the best photograph we obtained with Voyager one it didn't come very close to Europa would be much better with Voyager 2 our pictures will be about ten times larger where the Poyser - huh but there's a very interesting feature here on this satellite you see these long straight lines down that southern hemisphere we don't know what they are they could be just surface markings or they could actually be crevasses long huge canyons if they are there much greater than our own Grand Canyon their place that's thousands of kilometres what's the size of the planet itself oh look this again is it's smaller than the earth but it's it's comparable to the moon fracture or whatever they are lying on the surface no more even right so we're looking forward to the next trip by this satellite Iowa is a pretty interesting satellite we have some people with remarkable imaginations but none of them had imaginations good enough to expect what we found on Isle it's a it's a very remarkable object in the solar system this is a color photograph showing it has a very goldish reddish color was with some white areas now we expected IO to be a little different and we expected it to have some salt flats on it and I think it does but one of the first things we noticed is it seems to be no evidence of cratering these other bodies of all shown craters from impacts and so white why shouldn't I well we thought maybe as we got closer we'd find more but we didn't we should have been suspicious of a few of the other features this rather strange looking ring feature here about in the center doesn't look like the sort of thing you find on the usual satellite that's not an impact oh no it is not I'll order this we do now at the time we first saw the photograph coming back from the spacecraft as as we got a little closer to the satellite we saw images like this now this was a evidence of lava flow it looks like a collapsed caldera and a very thin spreading of the dark material which is it was thought to be lava it wasn't until several days after we had gone by Isle that one of the lady engineers on our navigation team was working with some of the photographs and she was trying to fit the the circle of isle into a computer program and it wouldn't fit because it had a funny-looking bump on one side of it you can see if you look very closely down here that strange looking bump well turned out that that was not an artifact of the imaging system that was real so we finally conclude hey we have a volcano on active volcano shouting out as we flew by and not only those are one but if you look at this other bright spot in the image here you can see something a spouting up there see that's a portion of the satellite that's in the shade or the dark side right but the material is actually being ejected high enough so it's catching the sunlight there's no atmosphere on aisle so any material coming out of a volcano tends to follow a ballistic trajectory and fall back to the surface and the height of that these pins is something like 150 miles a lot of material coming out so suddenly we understood why the surface didn't have any craters yes they're all covered up apparently this has been going on they're active for billions of years yes at the present time now we have identified seven active volcanoes which were erupting during the few days that we flew by now you couldn't see anything like that if you flew by earth volcanoes just don't walk that frequently here I have several other photographs that demonstrate this a little more clearly here is a spout on the on the limb of the planet and again you can see the big fountain of material now we have pretty strong evidence that there's a great deal of sulfur coming out of these volcanoes and that's covering the surface with sulfur and a fair amount of it is also getting into the magnetosphere and leaving the satellite is another photograph of another volcano here you can actually see the dark material coming and spouting out and finally up a color version rather famous photograph showing a an eruption on right on the on the limb of the satellite it's approximately in true color now for scientific purposes sometimes we enhance these photographs and this is a composite photograph that includes some ultraviolet measurements and you can see up here they a the eruption and it enables us to determine the particle size coming out of the vent so Eyal I think is nominated as the most remarkable object in the solar system it's a it's a very active volcanic object and it's probably been going on for for billions of years and the surface is is fresh its new it's continually changing day by day throughout the Lewis Research Center in Cleveland Ohio we are directing work on modification of a centaur rocket for use with the shuttle some tile will be used to launch the Galileo probe to Jupiter in 1986 centaur will be carried into low-earth orbit [Music] the rocket will be released from the shuttle moved to a safe distance and fired sending Galileo to Jupiter during the upcoming Galileo mission we hope to learn quite a bit more about Drupal and its atmosphere let's go to a thern called Galileo mission to Jupiter which outlines the project [Music] [Applause] the spacecraft carries a parachute equipped polled targeted for deployment into Jupiter's turbulent atmosphere the probe will allow our first direct sampling of the Jovian atmosphere and is a forerunner of future probes designed to explore the Sun Saturn and satellites like Titan with considerable atmospheres the probe will descend into Jupiter to analyze and directly sample its atmosphere believed to be original material from which the solar system formed 4.6 billion years ago the Galileo mission named for the Italian astronomer who discovered Jupiter's four large satellites has been designed to use the gravity of those moons to bend the spacecraft flight path during its 24 month tour of the Jovian system as the probe samples the Jovian atmosphere scientific results will be relayed to the orbiter for one hour before the probe signal is lost at pressures of 10 to 20 earth atmospheres Galileo makes a close flyby of Io to study the moon's volcanic surface iOS gravity in turn bends the trajectory of the spacecraft helping to send it into orbit around Jupiter flying just 1,000 kilometers above the surface images of the moon show features as small as 50 meters [Music] after relaying probe science data to earth the spacecraft will orbit Jupiter at least eleven times making a close flyby of one of the Galilean satellites on each orbit yielding high-resolution images and detailed measurements of their surfaces gravity and magnetic fields as the orbit rotates about Jupiter the spacecraft will sample all regions of the planet's vast magnetic field the first full orbit of Jupiter brings Galileo to its first encounter with Ganymede the gravitational effect of the closed equatorial flyby reduces the length of the spacecraft's orbit from 200 to 90 days using photographic data from Voyager this computer simulated flyby of Ganymede shows Galileo's view of the icy moon Galileo will fly even closer to Ganymede in its second encounter with the moon each satellite flyby modifies Galileo's orbit sending the spacecraft on to its next encounter each flyby is 20 to 100 times closer than the voyager encounters the voyagers saw only the equatorial regions of these icy moons but Galileo will photograph the north pole of Ganymede providing a new perspective in the study of these large satellites a flyby of Callisto occurs on the sixth orbit of Jupiter the ancient cratered terrain of Callisto is closely studied as Galileo passes over the southern hemisphere of the outermost Galilean satellites [Music] the spacecraft will sweep within 200 kilometers of the surface of Europa at the end of its eighth revolution about Jupiter beyond alejos Europa encounters will give us our first detailed look at this moons mysteriously fractured surface seen by other spacecraft know better than we see Earth's moon through a small telescope during its 20 month mission Galileo will expand our knowledge of Jupiter and it's satellites revealing in detail the bodies and workings of this miniature solar system [Music] through the years we will learn more and more about the universe in which we live Galileo is just the beginning of what is possible this is why Ross saying to buy from the NASA Lewis Research Center in Cleveland Ohio until next time when we will travel to the next planet ad from Jupiter the great ringed planet Saturn [Music] [Applause] [Music]