Stars in Their Courses—Orbital Mechanics

The Great Courses
Show More

If you are a student or a professor:

Watch now

If you are a librarian or a professor:

Related videos

Coming Soon: Biosignatures, Moons, and More!
Explore the distinctive biosignatures that show the presence of life of any kind on an exoplanet. Then close with Professor Winn's tip sheet on exoplanetary discoveries likely in the near future--from evidence of moons to planets being destroyed by giant stars.
Living with a Dwarf Star
The most common stars are class M dwarf stars, which are smaller and less luminous than the Sun (class G). Earth-sized planets are much easier to detect around M-dwarf stars, especially if the planets are within the relatively close-in habitable zone. Explore examples and the prospect for life on such…
Lava Worlds
Explore the theoretical limit of the smallest possible orbit for a planet, taking into consideration tidal stresses and other destructive processes. Then focus on Professor Winn's search for such objects, which found probable lava worlds--planets heated to rock-melting temperatures by their extreme closeness to their host stars.
Nudge—Perturbations of Orbits
For the next three episodes, study the effects of gravity on the motions of more than two bodies. Here, see how even very small orbital changes--small perturbations--are significant. Such effects have revealed the presence of unknown planets, both in our own solar system and around other stars.
Escape Velocity, Energy, and Rotation
Begin the first of several episodes that dig deeper into Newton's laws than Newton himself was able to go. In this episode, apply the key concepts of energy and angular momentum to study how gravity affects motion. As an example, use simple algebra to calculate the escape velocity from Earth.
Living with a Giant Star
In billions of years, the Sun will expand into a red giant, possibly engulfing Earth. Learn how planet-finding techniques give astronomers insight into the processes inside giant stars. Then study the planets around these behemoths for clues about Earth's ultimate fate.
Planets Circling Two Stars
See how data from the Kepler spacecraft confirms a scenario straight out of the movie Star Wars: a planet with two suns. Investigate the tricky orbital mechanics of these systems. A double star also complicates the heating and cooling cycle on a planet. However, the view is spectacular!
Universal Gravitation
See how Newton was able to finish Kepler's revolution by formulating the law of universal gravitation, which says that every object exerts an attractive force on every other object. Also explore Newton's related discovery of the three laws of motion, which underlie the science of mechanics.
The Strangest Force
Begin your exploration of gravity with Isaac Newton and the famous story of the apple. Why was it such a breakthrough to connect a falling apple with the faraway moon? Review the essential characteristics of gravity and learn why small asteroids and large planets have such different shapes.
Why Study Exoplanets?
Learn about the exciting mission of exoplanetary science--the study of planets orbiting stars beyond the Sun. Review the eight planets in our solar system, which provide a baseline for understanding the more than 1,000 worlds recently discovered in our region of the Milky Way galaxy.
The Misplaced Giant Planets
Investigate 51 Pegasi b, the first planet detected around a Sun-like star, which shocked astronomers by being roughly the size of Jupiter but in an orbit much closer to its star than Mercury is to the Sun. Probe the strange characteristics of these "hot Jupiters," which have turned up around…
The Cat's Eye Nebula: A Stellar Demise
Turning from star birth to star death, get a preview of the sun's distant future by examining the Cat's Eye Nebulae. Such planetary nebulae (which have nothing to do with planets) are the exposed debris of dying stars and are among the most beautiful objects in the Hubble gallery.