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Wyoming Space Grant Consortium Newsletter - PaSSWORD

Volume 4, November 1, 1994

(The PaSS Center is Funded by NASA Grant #NGT-40050)

Public Talk by Dr. Eugrene Shoemaker Titled, "The Crash of Periodic Comet Shoemaker-Levy IX on Jupiter"

On July 16, 1994, Periodic Comet Shoemaker-Levy IX smashed into the Solar System's largest planet, Jupiter. The comet crash was probably the most closely watched astronomical event ever, and it was certainly one of the most spectacular. The comet was discovered by Dr. Eugene Shoemaker, Carolyn Shoemaker and David Levy on March 23, 1993. Dr. Eugene Shoemaker was invited by the PaSS Center to speak to the public about the comet, how it was discovered and the collision of the comet with Jupiter.

Dr. Shoemaker, on September 19, presented two talks at the University of Wyoming: a technical colloquium and a public talk. The technical colloquium was an afternoon talk in the University Classroom Building, to which about 75 people attended. The technical talk, entitled "Comets, Craters and Catastrophes", was about the possibility and effects of a large solar system body, such as a comet or asteroid, Comets and asteroids have struck the Earth in the past and have had devastating effects. According to Dr. Shoemaker, the dinosaurs were most likely extinguished by a large comet striking the Earth. Current theories place the impact of this comet at the northern tip of the Yucatan Peninsula in Mexico. The impact of a large comet or asteroid could throw enough dirt and dust into the atmosphere to significantly alter the climate of the planet. A significant climate change could easily wipe out thousands of species of plants and animals.

According to Dr. Shoemaker, such a devastating comet strikes the Earth about once every million years. Data, based upon geological and fossil records spanning the course of Earth's history, confirm that mass extinctions have occurred on a regular basis; the most probable cause of these extinctions is the impact of a large comet or asteroid on the surface of the Earth.

Following the afternoon colloquium, a dinner was held in honor of Dr. Shoemaker with approximately forty people attending the dinner. People enjoyed the chance to interact with Dr. Shoemaker in the social setting.

The PaSS Center also sponsored a reception in the Arts and Sciences Lobby just prior to the public talk. Refreshments were served while Dr. Shoemaker mingled with the general public and signed a few autographs.

The public talk was held in the Arts and Sciences Auditorium; it began at 8:00 PM and was attended by over 150 people. About one half of those 150 people were children. The talk was entitled, "The Crash of Periodic Comet Shoemaker-Levy IX on Jupiter". The public talk drew "oohs" and "aahs" from the audience as he showed one spectacular slide after another.

Dr. Shoemaker and his wife Carolyn are avid comet hunters and hold the world record for most comets discovered. Using an 18 inch Schmidt telescope on Mount Palomar in California, the couple, along with fellow comet hunter and friend David Levy discovered the most important comet of their careers. On March 23, 1993, using film that had been accidentally exposed to light and fighting inclement weather, the three comet hunters unknowingly photographed the comet.

Carolyn, comparing two photographs taken of the same part of the sky, but at different times, looked for any smudge on the film that seemed to change positions from one photograph to the next. She told her husband and David Levy that she thought she had found a comet, but it was unlike any other comet she had ever seen. The comet appeared "squashed".

In fact, it was later determined that the comet had passed too close to the planet Jupiter, and the planet's large gravitational field broke the comet into at least 21 different pieces. The separate pieces remained in a line along the original orbit of the comet giving the comet a squashed look. Upon a closer look through larger telescopes, including the Hubble Space Telescope, the comet seemed to resemble a "string of pearls" all headed in the same direction. What remained to be seen was what direction the "string of pearls" was headed.

In late 1993, it was announced by the astronomical community that Periodic Comet Shoemaker-Levy IX would strike the planet Jupiter in the summer of 1994. After a year of speculation of what the result would be, the comet hit Jupiter in July of 1994.

The string of pearls hit the planet over the course of 4 days. When the comet was discovered in March of 1993, the string was 200,000 kilometers long. By the time of impact in July of 1994, the string had stretched to over 7 million kilometers.

The impact, dredging up material from deep within the atmosphere of Jupiter, caused a "soot - like" material to form in the Jovian atmosphere, said Dr. Shoemaker. "It's going to be interesting to see how long those particles are going to stay up," he said.

In addition to the soot in the atmosphere, the impacts caused large gas plumes to rise well above the atmosphere of Jupiter. After the largest impact, a plume rose to over 4,000 kilometers above the Jovian atmosphere. "It's an enormously big plume," commented Dr. Shoemaker. He estimates that the biggest impacts delivered enough energy to match 100 million Megatons of TNT. Such an impact on Earth could cause the extinction of numerous animal species, he said.

Dr. Shoemaker said that he and his wife Carolyn recently joined the staff of Lowell Observatory in Flagstaff, Arizona. With the use of a computer controlled telescope and detector, they hope to "increase [the] rate of [comet] discovery by a factor of 10."

The public talk was video taped and is available to the general public. If you wish to own or view a copy please contact the PaSS Center at (307) 766 - 2862.

The Wyoming CD ROM & Teacher Workshops

Over the last three years, PaSS has co-sponsored (along with the Wyoming Institute for the Development of Teaching and the Wyoming Department of Education) teacher workshops, emphasizing image processing and the use of images in the classroom. Four workshops were held during the 1994 spring semester for Wyoming secondary school teachers. They were directed by Pat McClurg, Jim McClurg, and Steve Siegel. Approximately 110 teachers attended workshops in Cheyenne, Casper, Jackson, and Green River. The goals of the workshops were to help teachers develop new computer skills and to introduce them to motivating and creative classroom activities. Classroom activities were demonstrated for Earth Science, Physical Sciences, Biological Science, History and Geography.

Teachers have asked us to accumulate images used in these workshops and distribute them on CD ROM. In particular, we are collecting satellite and aircraft images of towns and cities in Wyoming so that students can have the opportunity of working with different images of their own region. A prototype CD ROM was distributed this year to science teachers throughout the state. After receiving comments from teachers regarding these CD ROMs, we will distribute a more refined, more user-friendly Wyoming CD ROM in 1995. If you received a 1994 CD, it is not necessary to contact us. Otherwise send a letter to the PaSS Center asking to be put on our CD distribution list.

We wish to thank many teachers who have given us time, feedback, and contributions regarding our workshops and CD, in particular, Brian Aivazian, Bob Burke, Steve Green, Dave Hamaker, John Howarth, Steve Siegel, Dana Van Burgh, and Robbie Wensky.

Undergraduate Students Perform "Real" Research

In an attempt to encourage undergraduate research in the planetary and space sciences, the PaSS Center announced the availability of funds for the hiring of undergraduates for Spring or Summer, 1994. The initial announcement was for Seed Money, and was distributed in Fall 1993. Because of the success of the initial group of undergraduate students, the Spring 1994 announcements for Seed Money Proposals included undergraduates. Regretfully, there was only one proposal submitted for this round of Seed Money proposals and it was not funded.

Students who were hired with 1993 Seed Money were interviewed regularly, so that their progress could be closely monitored. The feedback received from all of the students was excellent. Each of the students expressed a tremendous interest in their respective projects! Furthermore, students reported gaining an incredible amount of knowledge with each interview. Thus, we intend to offer Undergraduate Seed Money again (UPCOMING DEADLINES).

Eugene Zimmerman was the first student to be hired under the Undergraduate Seed Money Program. Gene was hired by Rex E. Gantenbein, Associate Professor in the Department of Computer Science, and as a result of working with Dr. Gantenbein, Gene will now be attending Graduate School. Prior to working with Dr. Gantenbein, Gene had no plans for continuing his education beyond his undergraduate career. Gene also worked with two Graduate Students in Computer Science while working for Rex Gantenbein. Gene spent nine months writing computer programs for the testing of Space Station Alpha's Communications Subsystem. He also was part of the research team investigating the algorithmic fault-tolerance of the afore mentioned software. Specifically, Gene labored to solve the problem of detecting Loss of Signal (LOS) and determining whether the LOS had been scheduled. As a result of this project, "further reliability will be obtained from the testing of the Fault Detection, Isolation, and Recovery in the Assembly/Contigency Subsystem for Space Station Alpha," according to Gene's final report. Gene's concluding remarks were the most exciting; "...this experience with research has instilled in the fellow a desire to continue the research while unfunded. This fellow now plans on applying to graduate school. If not for this research, the future plans of this fellow would be quite different."

Jason Miller was hired by John E. McInroy, Assistant Professor in the Department of Electrical Engineering. Jason's project goal was to develop an inexpensive method for calibrating robots. He was given a robot with four axes to manipulate. When Jason was hired, there were existing computer programs for manipulating two of the axes. He was given the task of changing the programs such that all four axes could be manipulated. Initially, Jason was given specific tasks but he soon progressed to working one-on-one with Dr. McInroy on the calibration of the robot. John McInroy stated in the final report that, "He (Jason) has gone far beyond the original tasks asked of him and has obtained a tremendous amount of practical and research experience."

The research that was performed by Jason and Dr. McInroy will be presented in a paper to be submitted to the International Conference on Intelligent Robots and Systems. Jason will also enter the IEEE Student Paper Contest using the results of his research.

"Jason's research produced a surprising result: by combining a laser with several prisms, it is possible to precisely measure the complete position and orientation of the robot's end effector," according to Dr. McInroy. The figure below is an illustration of the robot Jason was calibrating.

In the end, Jason reached the goal of developing a highly accurate calibration procedure with minimal costs. The cost for the method developed by Jason was only a few hundred dollars, while traditional means usually cost on the order of one hundred thousand dollars. The final report submitted by Jason Miller and Dr. John E. McInroy includes numerous figures, calculations, and circuitry for the robot. One of Jason's final comments during his last interview at the PaSS office was, "it has been hard but fun."

Pat Henricks worked on a project with Dr. William Reiners, Professor in the Department of Botany. Pat was given two LandSat scenes of Wyoming, each covering approximately the same 185 km by 185 km area. The two images were taken in 1984 and 1991, seven years apart.

The first task Pat addressed was geo-referencing the 1991 scene using the 1984 scene. Before any comparisons could be made, Pat discovered that he needed to match the resolution of the two scenes. The most noticeable change between the two scenes was, "the shrinkage in size of many lakes and ponds," according to Pat. In his analysis, Pat learned many different techniques for detecting change and when particular techniques are useful. Jerry Dodd was recently hired by Dr. William Gribb, Associate Professor in the Department of Geography and Recreation. Jerry will be studying geothermal satellite images with the intent of mapping specific regions. He plans to use an existing computer program to look for areas of natural resources. Before Jerry can begin to analyze various regions, he must first modify the satellite data to be read in by the computer. Jerry and Dr. Gribb have been working out some computer problems and are anxious to begin the project. Jerry said he is very excited about the project because it is exactly the type of work he wants to do when he graduates.

1994 Fellowships Awarded

Eight Graduate Fellowships were awarded for the 1994/1995 academic term. The Wyoming Planetary and Space Science Center congratulates all of the Graduate Fellows! Recipients, advisors, and a brief description of each student's proposed research follows.


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