Walking up and down the hallways of Davey Lab at Penn State, you can find astronomers searching for and characterizing exoplanets, monitoring supernovae and other exploding stars, and measuring the details of the accelerating expansion of the Universe to determine the nature of dark energy. In Astro 801, we learn that with only the ability to measure the light from these distant, unreachable objects, we can still determine how the Solar System, stars, galaxies, and the Universe formed and evolved since the Big Bang. We are all citizens of the Universe, and in fact, you are made of starstuff. Come learn where the atoms in your body came from, and what will happen to them long after we are gone.

Clarifying the effect of axial precession on the calendar and the date of perihelion and aphelion

Relativity Lite is designed to accompany the main text in a course like General Astronomy, Physics for Poets, Learning Science Through Science Fiction, and Natural Science Inquiry. Relativity Lite was written for math-phobic students, so it translates the mathematical equations conventional relativity texts rely upon into pictures that are readily understood and contain within them the mathematical essentials. This book provides the comprehensive coverage needed to understand, in sufficient depth, Special Relativity, General Relativity, and Cosmology.

The site also includes an emulator that is able to run the Mac OS9 application RelLab on Intel macs or Windows machines, so that one can see how the Twin Paradox, the Barn and Plane Paradox, acceleration, and even user-designed scenarios play out.

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!

The video "Safe and Sorry - Terrorism & Mass Surveillance" is a resource included in the Space sciences topic made available from the Kurzgesagt open educational resource series.

Global Satellite Navigation Systems (GNSS), such as GPS, have revolutionized positioning and navigation. Currently, four such systems are operational or under development. They are the American GPS, the Russian Glonass, the European Galileo, and the Chinese Beidou-Compass. This course will address: (1) the technical principles of Global Navigation Satellite Systems (GNSS), (2) the methods to improve the accuracy of standard positioning services down to the millimeter accuracy level and the integrity of the systems, and (3) the various applications for positioning, navigation, geomatics, earth sciences, atmospheric research and space missions. The course will first address the space segment, user and control segment, signal structure, satellite and receiver clocks, timing, computation of satellite positions, broadcast and precise ephemeris. It will also cover propagation error sources such as atmospheric effects and multipath. The second part of the course covers autonomous positioning for car navigation, aviation, and location based services (LBS). This part includes the integrity of GNSS systems provided for instance by Space Based Augmentation Systems (e.g. WAAS, EGNOS) and Receiver Autonomous Integrity Monitoring (RAIM). It will also cover parameter estimation in dynamic systems: recursive least-squares estimation, Kalman filter (time update, measurement update), innovation, linearization and Extended Kalman filter. The third part of the course covers precise relative GPS positioning with two or more receivers, static and kinematic, for high-precision applications. Permanent GPS networks and the International GNSS Service (IGS) will be discussed as well. In the last part of the course there will be two tracks (students only need to do one): (1) geomatics track: RTK services, LBS, surveying and mapping, civil engineering applications (2) space track: space based GNSS for navigation, control and guidance of space missions, formation flying, attitude determination The final lecture will be on (scientific) applications of GNSS.

The video resource "Saturn: Crash Course Astronomy #18" is included in the "Astronomy" course from the resources series of "Crash Course". Crash Course is a educational video series from John and Hank Green.

From honey bees to cells, viruses, and atoms -- understanding the scale of the very small