Khan Academy
Khan Academy: Angular Measure 2
Looking for an easier way to do angular measurements? This page introduces you to a trick by using skinny triangles with small angles. The skinny triangles lets the astronomer assume right triangles and then they can use trigonometry to...
Alabama Learning Exchange
Alex: Cosmic Measurements
In this instructional activity, students will use hands on inquiry in cooperative learning groups to understand, develop and analyze common measurements used by astronomers. Students will use common objects such as straws, twizzlers, or...
Science Buddies
Science Buddies: A Puzzling Parallax
Did you know that ancient astronomers could measure the distance to other stars? They could also distinguish between stars and planets. How could they do that without modern technology of telescopes? See if you can discover the link...
NASA
Nasa Star Child: What Is a Light Year and How Is It Used?
This is a definition and example of how distance is measured in astronomy, such as the distance between our earth and the stars.
PBS
Pbs Learning Media: Birth of a Supernova, Type Ia
In this interactive activity from NOVA Online, learn about a type of exploding star - a Type Ia supernova - that is so bright that astronomers can measure the distance to the galaxy in which it resides, and even learn which elements make...
Other
Ellinogermaniki Agogi: Eratosthenes Experiment
A profile of the ancient Greek mathematician, geographer, and astronomer, Eratosthenes. Looks at his many accomplishments, including measuring the circumference of the Earth and the distance to the Moon and the Sun. Includes links to...