Studying astronomy can strengthen your knowledge of math, science and the Earth’s place in the universe. A free online astronomy course might be hands-on and involve the use of telescopes, or it might rely more on printed materials. In the latter case, your course is likely to include readings, assignments and exams to help you learn about the solar system, stars, planets and galaxies.

Astrobiology at Stanford University

The class approaches human biological history from an astronomical standpoint to try to answer questions about the origins of humanity and whether or not humans are alone in the universe. It’s designed for students with a background in science. Students may download lectures from iTunes.

Astronomy Lecture Series at the University of California – Berkeley

Berkeley offers several free astronomy lectures that cover a wide range of topics. Students can experience lectures focused on astrophysics, general astronomy, X-rays and ultraviolet radiation. These lectures are available as both audio and video files that one can watch through YouTube or download from iTunes.

Astronomy Talks at Technology, Entertainment, Design (TED) Talks

The TED conferences have included a number of lectures dealing with astronomy and related topics. Students interested in supplementing their own knowledge or astronomy background can view lectures about black holes, life in the universe, discovering new planets and the way the universe is designed. These talks and lectures can be downloaded or streamed directly from the TED homepage.

Comparing Stars at The Open University

This course focuses on stars and stellar properties. Students in this course study temperature and luminosity and are introduced to essential concepts and theories about the universe. For example, the course introduces and explains the Hertzsprung-Russell diagram, which is used to understand the qualities of stars.

Essential Radio Astronomy at the National Radio Astronomy Observatory

The course is designed for advanced undergraduate students and graduate students with some prior knowledge of astronomy, engineering or physics. It introduces the concept of radio astronomy and then covers topics like using antennas, radio telescopes and radiometers. The course also covers pulsars and spectral lines. All of the lessons are accessible through the website, though it’s encouraged that students obtain a copy of the course’s recommended textbook for additional training materials.

From Here to the Edge of the Observable Universe at the University of Cape Town

This course is presented as a lecture series in the form of podcasts. It presents an overview of current astronomical theories and knowledge. Lectures cover the solar system as well as the Sun’s and the Earth’s climates. The series ends with a lecture about whether or not humans are alone in the universe.

Frontiers and Controversies in Astrophysics at Yale University

This course covers three main topic areas: dark energy, black holes and extra-solar planets. The class pays specific attention to contemporary projects that can help students understand the theoretical implications of these topics. Students can stream audio and video content for this course on iTunes and YouTube and download other course materials directly from the course website.

Hands-On Astronomy: Observing Stars and Planets at the Massachusetts Institute of Technology

This is an introductory course that teaches how to use small telescopes. This class is designed for both researchers and hobbyists alike. Students receive instruction and information about electronic imaging, spectroscopy and data processing, as well as tips for better observations. Free lecture notes are available from the course website.

Introduction to Astronomy at the Massachusetts Institute of Technology

This undergraduate course introduces students to the scientific study of the solar system, stars and the universe. The course includes downloadable lecture notes, exams and assignments as well as a list of external resources. The curriculum utilizes a variety of astronomical models and observations to convey the material; topics covered include stellar structure, X-ray reflection and nuclear energies.

Putting Together the Pieces of the Universe at the University of California – Irvine

This lecture, which is offered in video format and can be streamed directly from the lecture homepage, deals with different galaxies in the universe. Specifically, the lecture discusses the importance and functionality of dark matter in the creation of galaxies.

Introduction to Astronomy and Planetary Science at the Planetary Society

This class was a college course offered through California State University Dominguez Hills and their very impressive distance learning DHTV program and young scholars programs, the latter offering college courses to high school juniors and seniors throughout California.  All 13 action packed, or at least information packed, lectures are now archived for everyone. So, find a topic you like and dive in, or enjoy the whole course. With a strong emphasis on using amazing space images and video to illustrate the tour of topics, hopefully you will find the classes entertaining as well as educational.

Hands-On Astronomy: Observing Stars and Planets at Massachusetts Institute of Technology

MIT’s Hands-On Astronomy: Observing Stars and Planets is also a free OCW course that was initially taught to undergraduates. Access course materials any time you want, but you won’t communicate with instructors.  You’ll learn techniques for using small telescopes to research and observe planets, stars, the Moon and other celestial bodies. Other topics you’ll study include spectroscopy and electronic imaging of objects in space.

Telescopes and Spectrographs at The Open University

Based in England, The Open University is a distance learning institution that provides OCW courses through its OpenLearn system. Telescopes and Spectrographs is an Open University OCW course that is available to you for free.   The course will introduce you to spectrographs and telescopes as well as other technologies used to observe and record objects in space. You’ll learn how to calculate the light-gathering power, angular magnification, field-of-view and image scale of reflecting and refracting telescopes.

Extrasolar Planets: Physics and Detection Techniques at Massachusetts Institute of Technology

This undergraduate-level course focuses on the fundamentals of planetary atmospheres and interiors as they relate to extrasolar planets. Students can view selected lecture notes, which are available as PDFs. Some assignments can also be accessed.

Hands-On Astronomy: Observing Stars and Planets at Massachusetts Institute of Technology

This undergraduate course was originally offered in 2002, and students can learn about telescopes, visual observation techniques and electronic imaging. Lecture notes are available and include observing tips, optics information and color imaging.

Galaxies, Stars and Planets at The Open University

This 8-hour course unit is a series of lectures covering the scale of the universe, objects that can be found in the universe and planet sizes. The unit ends with questions that students can use to test their knowledge of the subjects covered, in addition to an answer key.

Astronomy at University of California – Berkeley

This non-credit course was originally offered in fall of 2011 and can be viewed online or downloaded. It includes several of the course’s original 29 lectures that last about one hour each. The course focuses on modern astronomy, the galaxy, the universe and the evolution of the stars.

Frontiers and Controversies in Astrophysics at Yale University

This course focuses on extrasolar planets, black holes and dark energy. Students can view lectures or download lecture transcripts and access class notes in PDF format. Lecture topics include planetary orbits, tests of relativity and Hubble’s Law. In this free course, students can download one of the exams and view answers for both exams included in the original course.

Introduction to Astronomy at Duke University

This is an introduction to astronomy through a broad survey of what we know about the universe and how we know it. This 10 week course requires an interst in astronomy and some High School algebra.

Exploring Black Holes: General Relativity and Astrophysics at Massachusetts Institute of Technology

Introduction to black holes.  This course is designed for students who want to learn more about relativity, astrophysics and cosmology.

The Early Universe at Massachusetts Institute of Technology

Introduction to modern cosmology.  This course focuses on the big-bang theory (no, not the CBS sit-com) and particle theory.

Modern Navigation at Massachusetts Institute of Technology

This is an introduction to navigation techniques using celestial bodies and satellite positioning systems.

The Big Bang at Open University

An advanced study of the Big Bang. Students explore three lines of evidence. Required time commitment: 20 hours.

Jupiter and Its Moons at Open University

This course examinates Jupiter and its satellite family. Students learn to identify the surface of Jupiter and learn about planet and its moons in this 12-hour introductory course.

Introduction to Active Galaxies at Open University

This intermediate-level course introduces us to active galaxies. Class topics include active galaxies, starburst galaxies and normal galaxies.

The Moon at Open University

This course explores the moon. Students learn about the moon’s surface, placement and construction.

Cosmology at Massachusetts Institute of Technology

This course is an introduction to astrophysical cosmology. Course focus is on Cosmic Microwave Background (CMB) radiation and galaxies.

The Sun at Open University

In this course you will examine the Sun, including its structure, electromagnetic spectrum and distance measurement.

Comparing Stars at Open University

This astronomy course explores the properties of individual stars. Course topics include luminosity, radius, composition, photospheric temperature and mass.

Icy Bodies: Europa and Elsewhere at Open University

This course presents the history of icy satellites. Students will learn about Europa and other icy bodies.

Telescopes and Spectrographs at Open University

This in-depth introduction to telescopes and spectrographs will present the basic principles of geometrical optics.

The Evolving Universe at Open University

This course examines the origins of the Universe and explores how it has evolved from its beginning to present day.

Particle Physics of the Early Universe at Massachusetts Institute of Technology

Topics in this graduate-level course range from general relativity and standard big bang cosmology to particle physics and cosmic strings.

Astrophysics II at Massachusetts Institute of Technology

This advanced astrophysics graduate-level study explores a range of topics, including phenomenological cosmology and galactic dynamics.

Modern Astrophysics at Massachusetts Institute of Technology

This course examines fundamental celestial body processes and how physics applies to these objects.