What goes up does not always come back down, the North Star is not the brightest in the night sky, and in North America, the sun is only directly overhead at noon twice a year, according to People magazine’s sexiest astrophysicist alive for the year 2000. During Wednesday’s All-School Meeting, Dr. Neil deGrasse Tyson began his speech on the possibility of extraterrestrial life by dispelling a number of popular scientific myths. Dr. Tyson, the director of the American Museum of Natural History’s Hayden Planetarium, delivered a presentation titled, “Frontiers of Cosmic Discovery.” Brought to Phillips Academy by the Bernard and Louise Palitz Lecture Fund, Dr. Tyson hosts PBS’s popular NOVA series “Origins.” Throughout the majority of his speech, Dr. Tyson analyzed the possibility that life exists on planets other than Earth. He hypothesized that Mars, Jupiter’s moon Europa and Saturn’s moon Titan are the three bodies most likely to host life. Mars’ many craters and rivulets point to the possibility that lakes once existed on the planet. Jupiter’s moon Europa is covered by ice and more liquid water than is in all the Earth’s oceans put together and resembles some places on northern Earth. Titan, one of Saturn’s moons, does not have water but does contain lakes of methane. These lakes are similar to those that scientists suspect existed on Earth before the advent of life. Dr. Tyson believes that the probability that life exists on other planets is very high. The elements that compose life, he told students during the All-School Meeting, are the most common elements in the universe. Dr. Tyson also talked about the types of extraterrestrial life that might exist. He explained that life in outer space might not contain DNA, and thus might not even faintly resemble life on Earth. During the presentation, he also attempted to pique students’ interest in science, emphasizing its importance in everyday life. According to Dr. Tyson, “scientists are acutely aware of the way things work,” a fact that enables them to explain the world around them. Dr. Tyson explained how a knowledge of Newton’s First Law of Motion, which states that an object in motion remains in motion unless an outside force acts upon it, would make a person aware of the importance of seat belts in preventing serious injuries in car accidents. He also illustrated how several commonly held beliefs about space are fallacies. Students have long been taught that what goes up must come down, but Dr. Tyson noted that NASA has placed “all kinds of hardware on the moon that’s never coming back.” He also stated that the North Star, contrary to popular belief, is only the 49th brightest star in the night sky, or, in Dr. Tyson’s words, “[the North Star] is dull and boring.” He ridiculed the idea that the sun is directly overhead at noon, saying, “people tell you this because they’ve never looked.” The astrophysicist, in accordance with his exhortation to the audience “to be sharp of mind for the next 20 minutes,” explained the math involved in the study of outer space. He stated that while a lifetime lasts three billion seconds and a quadrillion accounts for the “sum of all the sounds and words ever uttered,” scientists estimate that there are as many as a sextillion stars in the universe. Dr. Tyson showed the audience a letter written to him by a psychology professor at the University of Pennsylvania. The letter contended that study of the universe caused feelings of insignificance among humans. Dr. Tyson disagreed with this assessment, stating that though the vastness of the universe may make humans appear small, we should be proud of the human race for solving the mysteries of space. At the conclusion of the lecture, little time remained for a question and answer session, but Mr. Tyson did answer two student questions. He told the audience that communication with aliens would most likely be impossible due to the vast distances between objects in space. Thousands of years would be required before a message could reach another planet. After his presentation, he met with interested students in the Gelb Science Center to discuss astrophysics and other scientific topics. Also during Wednesday’s All-School Meeting, the administration tested new procedures for taking emergency attendance. Deans asked students to practice filing into the chapel in accordance with the rules of what Associate Head of School Rebecca Sykes termed the “disaster recovery process.” The administration instructed students to go immediately from classes to the chapel. There, attendance was taken in the usual manner as quickly as possible. Students then sat in the area of the chapel reserved for their cluster. Flagstaff Cluster practiced a different emergency procedure from the other clusters. Members of Flagstaff did not take attendance, but instead sat in alphabetical order in the Flagstaff section of Cochran Chapel. Both emergency procedures were successfully executed.