"LIVE FROM THE STRATOSPHERE" P R O J E CT U P D A T E # 21 PART 1: Television history: a unique experience for many of us PART 2: Please share your media coverage PART 3: A Brazilian occultation adventure PART 4: April gets ready for the first TV broadcast PART 5: Astronomers don't always look through telescopes _______________________________________________________________________ Some (exhausted but pretty pleased) words from Executive Producer and Project Director Geoff Haines-Stiles: PHEWWWWW! Seven and a half hours of live television in two days! NOT your usual sort of program schedule, but then--in the PASSPORT TO KNOWLEDGE project--live video and tape are delivery mechanisms for experiences, more than traditional tv programs. That's why we call PASSPORT a series of "electronic field trips": the video is designed to deliver faces and places and processes to personalize and dramatize that higher level of information and interaction to be found online, and to climax the hands-on learning suggested by the printed materials distributed in advance. That said, this week's video was SPECIAL... and we hope you realize you were part of television history. This was the FIRST-EVER two-way video to a plane in flight, involving technological wizardry, courtesy of NASA's Advanced Communications Technology Satellite, and much hard work from NASA's Jet Propulsion Lab, Lewis Research Center and Lockheed Martin, New Jersey. It was state-of-the-art technology deployed not for missile systems but to serve education--an encouraging precedent, and a tribute to America's teachers and students. Congratulations, ACTS team, and thanks. Second, the KAO team, together with teacher April Whitt from Georgia, students Brian Scott from Texas, and Laura Smith from California, showed that it was possible to have students travel with them via technology during a scientific research mission, and look over their shoulders. This was REAL SCIENCE, REAL SCIENTISTS, REAL LOCATIONS, REAL TIME. And we're delighted to find that "boys and girls of all ages" found this REAL exciting! Again, this is a precedent for future NASA missions, specifically SOFIA, the KAO's successor, but more generally for trips to Mars and beyond! Let us know how it worked for you and your students. Lastly, it prototyped what we hope will be part of future PASSPORT projects, a network of participants in schools and science centers, accessing the video through whatever means possible--PBS station, NASA TV, cable company, junior college (we should probably publish a book of "war stories"/tips for next time--about how people eventually obtained the tv signal!) in order to structure an event customized to reflect local circumstances. PASSPORT proposes a menu of possibilities: local sites choose and execute what they think will work best for them. That sounds right no matter which political party and philosophy you support! So, thanks for your participation and interest. On to the last video program, but it's important to remember that the online components remain LIVE through November 17, and that there are many activities--star count follow-ups, KAO position plotting from the archived data--that can help tapes and text COME BACK TO LIFE for students in the months ahead. AND PLEASE... THINK ***EVALUATION*** EITHER USING THE FORMS IN THE PRINTED GUIDE, OR ONLINE! WE WANT TO KNOW THE RESPONSES OF YOU AND YOUR STUDENTS IN SOME DETAIL, TO HELP STRUCTURE OUR NEXT ELECTRONIC FIELD TRIPS! So, still, Onwards and Upwards Geoff Haines-Stiles _______________________________________________________________________ This is a CALL to each of you to help us document our collective LFS experience. In a few weeks, we will be asking folks to help evaluate the program. For now, we would very much like to obtain copies of media coverage of the Live From the Stratosphere project. We ask that anyone who is aware of coverage of any type (newspaper, TV, etc.), PLEASE submit the articles and send video tapes of your event coverage to: PASSPORT TO KNOWLEDGE, 41 ROWAN ROAD, SUMMIT, NJ 07901 Phone: (908) 273-4108. _______________________________________________________________________ A BRAZILIAN OCCULTATION ADVENTURE By Ben Burress, Tracker Operator Working on the KAO is not just working on the edge of the stratosphere, but sometimes simply on the edge. One mission in particular could have held its own in the box office for sheer edge-of-the-seat excitement. Once in awhile an astronomer desires to observe an event called an "occulatation". An occultation is when a planet, asteroid, or comet passes between Earth and a star, casting its shadow across the face of our planet. Astronomers take advantage of this celestial alignment by observing the light from the star being occulted and measuring the effects of the occulting body's atmosphere, if any, on that starlight. By measuring in what manner the starlight dims as the two objects get closer together, astronomers can determine things like the temperature or the density or the structure of the occulting object's atmosphere. Or, for a body with no atmosphere, a precise size measurement can be made by measuring how long it takes for the star to disappear and reemerge. At any rate, occultations are the most exciting types of missions on the KAO as far as the criticality of timing and positioning of the aircraft, and the fact that the occultation event lasts for mere seconds. One particular occultation mission stands out in my mind because of the many hurdles we went over and the numerous times the entire mission was stopped dead. The object that our astronomers predicted would occult a star is a comet called Chiron, orbiting the sun in the outer solar system. The objective of the astronomers, Dr. Edward Dunham of NASA Ames and Dr. James Elliot of MIT, was to study the nature of the halo of material outgassed from the comet. To encounter the shadow of this particular occultation we had to fly over the Atlantic Ocean off the coast of Brazil, at precisely the correct time in precisely the correct location. The shadows of small, distant objects can be hundreds of miles across, but move over the face of the Earth at many miles per second, and therefore the events do not last very long. We took off from Ames one day in March, 1994, and flew to Puerto Rico, where we spent the night in preparation for our "practice flight": a flight from Puerto Rico to Brasilia, Brazil during which we observed the star that would be occulted a few nights later. This was to become familiarized with the star field as much as it was for the astronomers to gather some data on the star's light. Our first hurdle was still in place when we took off from Puerto Rico: we had still not been granted permission to land in Brazil, or fly over its air space. I understand that the permission was granted while we were in flight, and we landed in Brasilia on schedule. Our next hurdle seemed to be to convince the Brazilian military leaders that we were not, in fact, flying over their country with a huge infrared camera in order to spy on them, but to watch a ball of dirty ice fly in front of a star. All along, the leading military officers were dead set against our very presence in Brazil, and probably the only reason we were able to gain admittance to that country was the fact that Ted Dunham had been in close correspondence with a leading Brazilian astronomer, who went to bat for us. In the end, we were tentatively allowed to fly our mission, but we had to submit our flight plan a couple days in advance and promise not to deviate from it. There we were, sitting in the KAO at the airport, engines running, buckled in our seats, all ready to go, when the tower suddenly denied us permission to take off. On board we had two Brazilian guests, Ted Dunham's astronomer associate and a Brazilian Air Force major. While the former had saved our day a couple of times already, it was our other guest who now went to bat. The major talked to the tower for at least five minutes, and discovered that the reason we had been denied permission was because the flight plan we had filed earlier that day "differed significantly from the one we had provided two days earlier." The major consulted with Dr. Elliot concerning the reason for the change, which was mainly due to the fact that the newer flight plan was based on more precise position data on the comet, Chiron (the closer an occulting body comes to the star it will occult, the more precisely the position of its shadow's path on the Earth can be calculated; sometimes the difference can be enough to influence a flight plan). The major came through for us, and convinced the tower to let us take off. The flight itself went very well. Of course, any number of things could have happened to spoil the entire week-long mission; any piece of telescope equipment could have failed, even momentarily, at the wrong time, causing us to lose everything. The tracker might have failed, a camera, the telescope systems, power, compressors, autopilot, etc., etc., etc. This is why this sort of mission is so nerve-wracking. A lot of time and money go into getting the airplane to a remote location, obtaining diplomatic permission, transporting personnel and equipment, and it can all come to nothing if the smallest thing goes wrong at the wrong time. For an event that lasts only ten seconds, a simple loss of track, when for one reason or another the tracker computer temporarily loses track of the track object, could have wiped out everything. In the end, the mission was a success, despite all of the potential show-stoppers that reared up along the way. By this time, it was no surprise to anyone when, only hours before our departure from Brazil, we had still not obtained diplomatic permission from the Chilean government to land at our intended fuel stop on Easter Island.... _______________________________________________________________________ GETTING READY TO BROADCAST April Whitt Monday, October 2, 1995 It's rehearsal day - or the first day of rehearsals, anyway. Remember to wear closed-toe shoes! (I knew that, but still had sandals on, and was reminded at least six times by various crew members. The Kuiper is full of rails, metal corners and racks on which to damage one's unprotected feet. As it is, a helmet would have been more useful today - I cracked my head a good one on the door frame, climbing out of the plane this morning. No blood, no foul though.) During a 10:00 am meeting with Wendy Whiting and other NASA people I get a glimpse of just how much effort has already gone into this project. For months, this support team has been working hard, organizing, discussing, planning and re-planning, solving the problems - they've done a great job! Different people report on concerns still pending: "Will I need a car in Houston?" "Where's the airphone and when will it be back from its modifications?" "What about that long cable for the camera?" Walt and Juan give updates. Mr. Haines-Stiles wants a production meeting every day. Afterwards, Allan Meyer describes the process of choosing a flight path that matched the dates of broadcasts. One limiting factor is the ACTS (Advanced Communications Technology Satellite). Its orbit carries it through the Earth's shadow (shutting it down) at only two times of the year - close to the equinoxes. At other times it misses the shadow or only goes through a small portion of it. While in the shadow, its solar panels are inoperable and it shuts down. The broadcast dates unfortunately fall in that time frame when the satellite will shut down early in the morning (or late at night depending on your time zone). So there are all kinds of variables to consider. What objects do you want to view? At what seasons of the year and times of night are they visible? When do they rise high enough above the horizon for the KAO's telescope to acquire them? Are those times reasonable for a broadcast that begins on the East coast? (no - which is why we leave from Ames or Houston) Houston's time zone is a better one, but the disadvantage of an east to west flight is that the telescope, pointing out the left side of the place, will always point south. A problem if you want to see something in another part of the sky. So the flight path will zig and zag to get everything in. Sometimes when an object is not real high in the sky, the pilots can even tilt the plane a bit to allow the telescope to better pick up an object. The objects for Friday's flight include: M17 (sometimes called the Omega Nebula) It's in the constellation of Sagittarius and is visible even in bright twilight, so we can take off before the sun's completely set and still acquire it. There are a few bright stars nearby to help find it. W51 - a star forming region halfway across the galaxy (much further than M17). It's still bright in the infra-red, but the visible "finding stars" are much dimmer. Bernard 335 - Jackie Davidson wants to get some more data on this star. It may be variable, but she needs more information to corroborate. M57 - the Ring Nebula. An older star that has puffed off its outer layers of gases, which are expanding in a bubble. From Earth the bubble looks like a ring around the leftover shrinking star in the middle, hence the name. Some dust has formed inside the bubble and may be detectable in the infra-red. M57 is also labeled NGC 6720. Saturn - a calibration object. But maybe we can see the moon Titan as well. M33 - a spiral galaxy that has a fairly bright star-forming region. Then the satellite shuts down, so we can't talk with groups on the ground any more. That's quite an impressive array of objects. The "M" designation is for Messier objects. Charles Messier was a French comet-hunter. During his sky-scanning sessions, he kept finding brightish blobs with his telescope, but they weren't comets. He started listing them in a catalogue so he wouldn't waste time on one the next time he ran across it. M17 was the seventeenth object on his list. The Messier objects are fun to find today - galaxies, nebulas, clusters: all kinds of pretty stuff. NGC is the abbreviation for New General Catalogue, but I think the "new" is relative. I think Herschel set it up over a hundred years ago. Check that, though. Allan has been working with the KAO for about 15 years or more. He has a collection of finding charts that help him acquire and track an object. They're carefully drawn charts on paper and some plastic overlay sheets (that he can put up against the screen where the tracker camera's image is showing). The acquisition camera (or "ack" as it seems to be called) has a zoom lens that can bring in from 3 to 12 degrees of the sky (helpful if one gets lost on a star field - zoom out a bit and get a perspective). The tracker camera has a much smaller field of view - only half a degree. The telescope tracker's job is to keep the object in the tracker camera's field of view while the research people guide their array to look at the object. On these flights, the detector array will look at several small parts of a galaxy (M33 for example) rather than the whole object. After all this information, it's time for more. Walt Miller explains how to use the black headsets that will be worn during the broadcast. They're a recent acquisition, and there aren't enough for everyone to have one, so we'll have to share. There are three places in the plane they can plug in, and the wires only stretch so far. The producer's voice and directions will come in our right ears (on the cue channel). We'll hear ourselves and the rest of the broadcast in our left ears (program channel) and there's a little "pot" on the bottom of the beltpack to adjust the volume of the questions coming up from the ground, also in our left ears. That makes at least three conversations to track, while one is talking to the camera at the same time. And be aware of which channel is which, which "push to talk" button is which, and try not to turn the cue channel volume down so you can't hear directions. We are assigned seats in the KAO and try out the headsets. Here on the ground it's fairly easy to keep track of what's going on, but I don't recognize people's voices yet, and have trouble telling who's talking in the headset. We skip back and forth between program and cue channels, and Juan offers to label the different buttons. Thank heaven for Juan and his television experience! His calm, collected attitude and Wendy's professionalism keep us better on track. Brian Scott (student from Houston) and Laura Smith (student from Los Altos High School here in the San Francisco Bay Area) will arrive tomorrow for the short practice flight. _______________________________________________________________________ CHASING METEORITES IN ANTARCTICA Dr. Scott Sandford Part of my research work at NASA involves the study of meteorites. Meteorites are pieces of rock that fall onto the surface of the Earth from outer space. Most meteorites are thought to come from asteroids and were probably originally flung into space during the explosions that result when asteroids collide with each other. Strangely enough, my interest in meteorites has taken me all the way to Antarctica. It may seem a bit surprising, but the world's coldest continent is also the world's best place to find meteorites. This is largely because the ice and snow preserve meteorites for up to a million years. In contrast, meteorites that land on other continents rarely last more than a few hundred years before they are plowed under, paved over, eroded beyond recognition, or lost by some other process. Meteorites that fall in Antarctica are slowly buried in snow. As this snow accumulates the weight of the snow on the top squeezes the snow below so hard that it turns into ice. Once the meteorites are encased in ice, they are protected from destruction. The meteorite- bearing ice flows very slowly down hill, usually until it reaches the ocean. At the ocean, the ice breaks off into large icebergs which float out to sea and melt. Thus, most of the meteorites that land in Antarctica ultimately end up getting dumped into the ocean where they sink to the bottom. However, there are areas in Antarctica called "ablation zones" where meteorites can be collected before they get into the ocean. Ablation zones are locations where the large moving masses of meteorite-bearing ice run into some kind of barrier, mountains for example. These barriers thrust the ice upward where it is exposed to the constant winds that blow in Antarctica. These winds wear away the ice by ablation and expose the trapped meteorites. [Ablation is a process where a solid material evaporates without first becoming a liquid. This is the same process that makes your ice cubes shrink in a 'frost-free' freezer!] In a sense, the flowing ice is a large conveyor belt that collects meteorites from large portions of Antarctica and delivers them to the ablation zone where they accumulate and can be collected by scientists. Some of these special Antarctic locations contain huge numbers of meteorites. One year I participated in a search expedition that found over 1000 meteorites in six weeks! There are many types of meteorites. Most meteorites that are found are of a relatively common type known as "ordinary chondrites." While all meteorites are of scientific interest (they can tell us a lot about the formation and subsequent history of our Solar System), people who study meteorites are especially interested in the rarer types of meteorites because they have generally been less well studied and are more likely to teach us new things. Here's how we search for meteorites in Antarctica. Each "morning" (since we search during the Antarctic summer the sun never actually sets while we're there), the men and women of the search party, of which there are usually 4 to 8, leave their tents and go out on foot or on snowmobiles to search. In good locations, the ice field being searched is created by a submerged mountain. This type of ice field is usually uncontaminated by terrestrial (i.e., Earth) rocks. It doesn't take a lot of skill to find meteorites on this type of ice field. Anything that isn't snow or ice is probably a meteorite. Unfortunately, many ice fields are found near exposed mountains and the meteorites are mixed in with a lot of terrestrial "junk" rock. Finding meteorites on these fields requires that every rock be painstakingly examined to see if it's a meteorite. You can usually tell whether a rock is a meteorite just by looking at it. Most meteorites have a distinctive black coating called a "fusion crust." The fusion crust is created when the surface of the meteorite is vaporized by the intense heat generated when the meteorite enters the Earth's atmosphere. However, one of the problems you have to deal with is that you occasionally stumble upon a 'mystery rock' that might be a meteorite... or it might not. Of course, these rocks may be the most exciting finds of the expedition because they potentially represent new and unique meteorites. Or they might be "junk" rock. In the most ideal of all worlds, you should simply collect everything you're not sure about, the theory being that it's better for the curators at Johnson Space Center, who later examine the samples more carefully (and who are relaxed, warm, and have lots of time), to sort it all out rather than have the expedition members (who are cold and tired and have limited time) agonize over it. In practice this does not always happen because: (1) to collect a meteorite, package it properly, record the data in a field book, etc., it is necessary that the scientist remove his or her gloves and risk freezing their fingers, and (2) because all the members of the expedition consider themselves to be immensely important meteoriticists and do not want to be exposed to possible ridicule should the people in Houston discover they have accidentally shipped them a penguin dropping or some such item. So what to do? Generally, the expedition members gather around the rock and "discuss" whether it should be collected or not. This generally solves the problem, either because some consensus is reached or because someone finally decides it would be less painful to remove his or her gloves than to continue to listen to the "discussion." In late January of 1989, I and three colleagues were searching for meteorites near the MacAlpine Hills in Antarctica. The weather was VERY cold and the ice field we were searching had a fair amount of terrestrial "junk" rock on it. We had already found a few meteorites when I came upon a 'mystery rock.' It did not look like a terrestrial rock of the type local to the area, and yet it didn't look like a normal meteorite either. Most meteorites look black, but this rock was a funny sort of greenish-brown. On the other hand, the surface of the rock had the characteristic smoothness of a fusion crust, as if the rock had entered the Earth's atmosphere at a very high velocity. After some discussion, the four of us were unable to come to a consensus about whether the rock was a meteorite or not, but I was reluctant to leave it behind. It was finally decided that I would put the rock - which weighed about one and a half pounds and was about the size of a fist - in my pocket. If no other rocks of this type were found, I would bag the specimen for Houston. If we began to stumble onto many more rocks of the same type, we would conclude that we had drifted into an area with a new kind of terrestrial rock and I would throw the rock away. On this note, the discussion was closed and we continued with our search. So of course we found one more such rock, a smaller one, and the "discussion" was renewed. This time I finally decided that the discussion was getting to be too frustrating so I bagged my specimen. The smaller sample was bagged soon thereafter. This proved to be a smart move. Several months later, when I was back at work at NASA's Ames Research Center, I received a call from someone at the curatorial facility at the Johnson Space Center. They wanted me to know that both of the 'mystery rocks' had turned out to be lunar meteorites. Yes, pieces of the Moon! So apparently, some time in the last 10 million years or so, a large asteroid or comet hit the Moon and the resulting explosion ejected pieces of the Moon into space. Some of these pieces ended up falling on the Earth as meteorites. Some of these landed in Antarctica and one of them came to the surface of the ice just in time to spend a day in my pocket. So..., the next time you're worried about doing something that may expose you to potential ridicule, you might just stop and ask yourself, "How many penguin droppings are worth one lunar meteorite?"