Books & Handbooks

Astronomical distances

The activities will consist of carrying out some practices of Astronomical Distances. The objective for the students is to understand and reproduce some methods that throughout history have allowed us to calculate the distance between the celestial bodies.


Earth-Sun distance

The method of traffic to determine the Earth-Sun distance is based on the Venus position on the solar disk viewed from two different points on Earth at the same time.

The practice consists in making two or more photographs from different places using the SimTV program to be able to determine the Astronomical Unit. We propose two different methods of realization. The first method is to make transit observations from different places. The second method is to measure transit contact times, also from different places.

In the accompanying documents, you will find both practice script for the students and a dossier for the teacher (method1).

You can download the SimTV program here.


Size of Sun

With a dark room we can find the angular size of the Sun, and with it and with a little trigonometry, the size of the solar radius.

In the attached pdf file you will find the dossier of the practice.


Size of Solar system


Once we know the value of the Astronomical Unit we can know the size of the orbit of any planet in the Solar System using the Third Kepler's Law.

In the accompanying documents, you will find the guideline of the practice for the students and the dossier for the teacher.


Distance to a star

One of the methods to determine the distance to a star is the measurement of its parallax angle, and with it, is possible to know what is the distance of the star.

In the attached document you will find the practice script.

Related Phenomena

Planetary Transit
Mercury's transit 2019
On November 11, 2019, a transit of Mercury can be seen from Catalonia.
Planetary Transit
Transit of Venus 2012
Between the 5th and 6th of June of 2012 we can observe a transit of Venus.
Planetary Transit
Transit of Venus 2004
El 8 de juny de 2004 es produirà el primer trànsit de Venus pel davant del Sol des de l'any 1882.
Planetary Transit
Mercury's transit of 2003
El trànsit serà visible en totes les seves fases des de l'Est de la península Ibèrica.

Related News & Activities

Related Material

Books & Handbooks
La història de transit de venus

Josep Manel Carrasco and Jordi del Río ofer us these comic, based in de Salvador Ribas's text.

Josep Manel Carrasco, ICCUB-IEEC