The Parallax Activity: Measuring the Distances to Nearby Stars

Determining the position of a star or other object in three-dimensional space is an important concept in astronomy. Finding stellar longitude (called right ascension) and latitude (declination) is easy enough, but it is much harder to find the radial distance to those objects. This lesson teaches how the distances to nearby stars are measured using the parallax effect: as the Earth orbits our sun, the positions of the nearest stars seem to wiggle back and forth compared to more distant stars. Knowing this parallax angle and the distance from the Earth to the sun, we can use the tangent function to measure the distance to a star. In this lesson, students will learn how parallax is measured and will practice using trigonometry to measure the height of local landmarks. They will then conduct an activity measuring the distances to “planets” and their parallax angles to simulated stars, then calculate the stars’ distances. Each team of students will need a simple quadrant built from a one-meter ruler, a protractor, a piece of string, and a weight such as a rubber stopper. They will also need calculators or trig tables to do the final calculations. This lesson will take approximately 90 minutes to complete.
For more information: blossoms.mit.edu/videos/lesson...

[@lightlabetc5183]

Thank you for this video ! I will be teaching a one week course on Astronomy, and plan to use a couple of your activities :)

[@marisaelenenadiejamusiccom3974]

This is one of the best videos on this subject.

[@BranchScience]

Very nice. Thank you.

[@paulcazza]

I didn't understand what angle I'm trying to measure when I'm trying to calculate the distance to a star. Yes one side of the angle is my line of sight to the star - but what is the other? If I'm standing on the revolving earth won't my line of sight to any other thing be changing by the minute? If I'm doing this at night so I can see the star presumably I can't see the centre of the sun at the same second? The second line can't be to something I can't see?

[@wentianxiang1155]

Teacher: when you use google to measure the distance from location to the top of mountain, it seems you measured the hypotenure of right triangle instead of adjacent side. Or, Google map has function to masure the horizontal distance for these two points?

[@anonimus461]

i`ve just hace one question, when he measure the distance from the university to the mountain, is the top of the mountain so the 11.25 km shouldn´t be the hypotenuse of the triangle ?

[@drewkavi6327]

Google Maps will calculate the flat distance, but at an astronomical scale since angles are so small the hypotenuse length can be considered (aprrox.) the same as the base

[@manamsetty2664]

If this was school would never miss a day

[@samishthadixit1728]

What's your country name David V

[@ashishkumarsharma1323]

he clearly said US