Describes how satellites and other tools of space technology have transformed classical geodesy into the science of space geodynamics. The establishment and the activities of the French Center for Geodynamic and Astronomical Research Studies (CERGA) are also included. (HM)

The author derives, applying perturbation theory, from a simple astronomical model the approximate periods of secular variation of some of the parameters of the Earth's orbit and relates these periods to the past climate of the Earth, indicating the difficulties in predicting the climate of the future. (GA)

Shows, by a judicious exploitation of the Runge-Lenz vector, that the Kepler initial value problem is endowed with a nice geometric structure which enables one to determine, after a single trivial arithmetic calculation, the orbit associated with any given set of initial data. (Author/GA)

Describes the construction and use of a star projector built from an overhead projector and high-impact polystyrene plastic. Includes patterns for the star charts and the projector frame. (MA)

Presents two exercises in astronomy: (1) the production of star trails and (2) the measurement of the distance between stars and their apparent movement in the sky. Includes directions, illustrations, and activity questions. (MA)

Describes a selection of audiovisual aerospace materials available from government and non-government sources. (MLH)

Discusses the problem with the career track in graduate study in astronomy. Reports that the number of postdoctoral positions has doubled in the last ten years and far exceeds the number of tenure-track openings in astronomy departments. (DDR)

Presents an activity that begins with a discussion that leads into the rationale behind the techniques used in the Search for Extraterrestrial Intelligence (SETI) program. Students decode a message intended for extraterrestrials and consider a number of topics related to the possible existence of extraterrestrials. (DDR)

Describes how a middle school librarian, initially dismayed at having the major constellations of the northern hemisphere painted on the school library ceiling, gradually found the painting to be a fine resource for mythology and astronomy, and eventually discovered it to be one enormous, fantastic, writing prompt. (SR)

Presents research on different techniques to determine the level of understanding among middle school students regarding the phases of the moon. Quotes student responses to provide some insight into students' level of understanding of general knowledge about the moon, moon phases, and modeling the phases. Presents implications for teachers. (KHR)

Describes the Virtual Solar System (VSS) course which is one of the first attempts to integrate three-dimensional (3-D) computer modeling as a central component of introductory undergraduate education. Assesses changes in student understanding of astronomy concepts as a result of participating in an experimental introductory astronomy course in…

Presented are the arguments of two different points of view on the mass extinction of the dinosaurs. Evidence of extraterrestrial impact theory and massive volcanic eruption theory are discussed. (CW)

Described are the contributions of 15 women astronomers to the modern understanding of the stars. Discussed are early women pioneers, early spectrographic studies, and recent women astronomers. A list of 29 references is included. (CW)

The difference in time between the emission and reception of light is called the "lookback" time. This article explores implications of lookback time and explains some of the puzzling questions posed by the scientific observation of cosmic history. Provides several pictures and diagrams. (YP)

Discusses an astronomy simulation activity introducing the concepts of rotation, revolution, and retrograde motion. Describes the activity procedures in classrooms. (YP)