General Astronomy - " This Wikibook introduces the reader to that tapestry and the process that revealed it to humanity. It presents astronomy not only as a field of knowledge, but also as a human endeavor in science."
Simulations
NASA Image Gallery Search - Search for images in the following galleries: New Horizons at Pluto, International Space Station, Mars Missions, Orion Spacecraft, Space Launch System, Earth Missions, Hubble Space Telescope, Spitzer Space Telescope, Cassini at Saturn, James Webb Space Telescope
New Horizons Image Gallery - "The New Horizons mission is helping us understand worlds at the edge of our solar system by making the first reconnaissance of the dwarf planet Pluto and by venturing deeper into the distant, mysterious Kuiper Belt – a relic of solar system formation"
Astronomy - "Astronomy is designed to meet the scope and sequence requirements of one- or two-semester introductory astronomy courses. The book begins with relevant scientific fundamentals and progresses through an exploration of the solar system, stars, galaxies and cosmology."
Open Courses
ASTR 101 (Saylor Academy) - " ASTR101, you will be introduced to our current understanding of the universe and how we have come to this understanding. We will start with the ancient Greeks and their belief that the universe was an orderly place capable of being understood. We will continue through history, as we acquired more information on the nature of the universe and our models of the universe changed to reflect this."
Introduction to Astronomy- (MIT OpenCourseware) - "Introduction to Astronomy provides a quantitative introduction to the physics of the solar system, stars, the interstellar medium, the galaxy, and the universe, as determined from a variety of astronomical observations and models."
UW Astronomy Educational Clearinghouse - "The Clearinghouse provides a way for astronomy educators to share assignments, activities, and teaching tips. This material is made available under a Creative Commons license that allows you to adapt it as you like, as long as you credit the authors and use it for non-commercial purposes. You may share your adaptation, but only under a similar license. If the original authors are unknown, please credit the "UW Astronomy Clearinghouse"
Videos
NASA Solve
NASA Solve (video)- "NASA Solve lists opportunities available to the general public to contribute to solving tough problems related to NASA’s mission through challenges, prize competitions, and crowdsourcing activities."