Galactic dynamics: potential theory, orbits, collisionless Boltzmann equation, etc. Galaxy interactions. Groups and clusters; dark matter. Intergalactic medium; x-ray clusters. Active galactic nuclei: unified models, black hole accretion, radio and optical jets, etc. Homogeneity and isotropy, redshift, galaxy distance ladder. Newtonian cosmology. Roberston-Walker models and cosmography. Early universe, primordial nucleosynthesis, recombination. Cosmic microwave background radiation. Large-scale structure, galaxy formation.

The Colliding Galaxies Model is an implementation of Alar and Juri Toomres' 1972 super computer model showing the formation of galactic bridges and tails under the assumption that galactic cores are point masses and that one galactic core is surrounded by 2D concentric rings of orbiting stars. The model assumes is that the stars (test particles) orbiting the galactic cores are non-interacting. When the two galaxies pass one another, tidal forces deform the star distribution into classic tidal features. Our EJS model reproduces this result showing that there is a long curving tail and that only the outermost ring of stars is affected by its companion galaxy. A thin bridge is also formed and some of the stars are captured by the companion galactic core.

Study of physical effects in the vicinity of a black hole as the basis for understanding general relativity, astrophysics, and elements of cosmology. Extension to current developments in theory and observation. Energy and momentum in flat spacetime; the metric; curvature or spacetime near rotating and nonrotating centers of attraction; the Global Positioning System and its dependence on general relativity; trajectories and orbits of particles. Subject has online component and classroom lectures are replaced with online interactions: manipulation of visualization software, access to websites describing current research, electronic submission of homework, and structured online discussions between undergraduates and alumni and with instructors and graduate specialists in the topics covered.

This course focuses on three particularly interesting areas of astronomy that are advancing very rapidly: Extra-Solar Planets, Black Holes, and Dark Energy. Particular attention is paid to current projects that promise to improve our understanding significantly over the next few years. The course explores not just what is known, but what is currently not known, and how astronomers are going about trying to find out.

Move the sun, earth, moon and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it!

This video segment adapted from NASA uses animation to illustrate the properties of meteor showers and comets. Included is are visualizations of a comet's tail and of Earth passing through a debris stream left behind by meteoroids.

This Java archive contains a collection of simple Easy Java Simulations (EJS) programs for the teaching of computer-based modeling. The materials and text of this resource appeared in an article of the same name in The Physics Teacher [Phys. Teach. 76, No. 45, pp. 474-480 (2007)].

In NASA CONNECT Water Below the Surface of Mars, students learn how geometry, geometric shapes, and navigation are used to explore Mars. They also learn how NASA researchers collect, analyze, and interpret the data collected from exploration to develop theories about the existence of water and life on Mars. Grades 4-8.

In this unit, students learn the very basics of navigation, including the different kinds of navigation and their purpose. The concepts of relative and absolute location, latitude, longitude and cardinal directions are discussed, as well as the use and principles of a map and compass. Students will discover the history of navigation and learn the importance of math and how it ties into navigational techniques. Understanding how trilateration can determine one's location leads to a lesson on the global positioning system and how to use a GPS receiver. The unit concludes with an overview of orbits and spacecraft trajectories from Earth to other planets.

Students explore orbit transfers and, specifically, Hohmann transfers. They investigate the orbits of Earth and Mars by using cardboard and string. Students learn about the planets' orbits around the sun, and about a transfer orbit from one planet to the other. After the activity, students will know exactly what is meant by a delta-v maneuver!

Students use satellite tracking software available on the Internet to monitor a very large satellite, the International Space Station. Using information from this online resource, students predict and graph the motion of the space station at their location and create a 3-D display of its path through the sky.