A VIEW OF VENUS (Una mirada a Venus)

Authors: José Manuel Orrego Álvarez: profesor

                Belarmino Álvarez Álvarez (15 years) 

                Daniel Dos Santos Machado (15 years)



                                       (Avda. Pedro Masaveu,18 Oviedo 33007 Spain)


E-mail: jmorrego@fundacionmasaveu.com






On June 8th 2004 there happened an important astronomic phenomenon known as “The Transit of Venus”. This an extraordinarily important event, though maybe not sufficiently well-known.

This astronomic event was attended by an school team made up of two secondary-school students and their teacher. Before the Transit, the team has carried out some research for a better understanding of it. A lot of data were gathered (photographs, notes, times and drawings), which was transformed into a report. This covers the following aspects: concepts about the orbit of the Earth, Venus, conjunctions, transits, distances, astronomic cycles, historic importance of Venus, utilization of observation tools, techniques for the calculation of the distance between the Earth and the Sun (the so-called Astronomic Unity) and calculation of the size of the Solar System.

The main result of this experience is that it has increased in the team the love for astronomy, the thirst for knowledge and, first of all, it has provoked a great deal of questions.



The study on the Transit of Venus came about as a strategy for the improvement of our students’ educational quality. Our main aim was to foster the knowledge of astronomy in order for them to learn elementary concepts, to have a clearer idea of our planet, and to know what we are and where we are.

We have decided to participate in this experience because of the need we feel to include an area of knowledge which is not sufficiently present in the National Curriculum. We consider this initiative as a strategy for the inclusion of a new area of learning in secondary schools. This implies that educational authorities should be willing to face the problems of a new educational view of learning in order to cause personal maturing, work teams, and educational quality.


Objectives of the project. (What do we want to archieve?)

To know how the cycles of the Earth and Venus function (movements of rotation, translation, precession, transits, and equinoxes).To be aware of the need to know the place where we live: planet, solar system, galaxy…

1. To understand the basics of ski mechanics.

2. To use instruments for astronomical observation.

3. To foster the interest in astronomy.

Specific objectives

With respect to teachers:

1. To make bigger our view of astronomy, by being aware of the need to know the universe.

2. To develop motivating, stimulating and coherent teaching actions.

3. To be aware of the questions that science poses, as well as the way ahead of us.

With respect to students:

1. To respect the individual rhythm of each student, and to understand the basic functioning of planet movements (mainly that of the Earth and Venus).

2. To foster the interest in astronomy by means of: the interpretation of the star map, the understanding of natural phenomena related to the terrestrial movement, the curiosity for the complexity of universe, i.e., the questions unanswered so far.

3. To use the acquired knowledge of astronomy in order to determine the distance from the Earth to the Sun.

4. To arouse the interest in astronomy.

5. To know the history of astronomy, and value the work of old scientists taking into account their limited means and knowledge.



All the activities have been carried out in our school, with the exception of some search on the Internet and some search in Oviedo’s Public Library. All along the last two terms of the academic year 2003/04 and July, the students have participated voluntarily and actively. We have made use of our free time; e.g., school breaks, some class time exceptionally available, free afternoons, as well as any other moment when the students could organize their free time to attend school. It is difficult to make out the number of hours we employed for this work, but we did devote some time every week.

Foreseen activities

Before starting our astronomic adventure, we proposed an interdisciplinary activity to several teachers. Thus, we first review some basic vocabulary: transit, eclipse, afelium, perifelium, planet, conjunction, opposition, elongation, zodiac corridor, ecliptic, zenith, universal time…

For a better understanding of the phenomenon, we built up a cardboard mini planetarium in order to imagine why the transit is produced. The students assimilated the concept of the coincidence of orbits and the movement of planets. We must make clear that the scales are false and the model has just a pedagogical function.

 We studied and read about the history of Captain Cook’s journey to Tahiti in 1769 onboard Endeavour; and we found out how there have been intrepid people with a great interest in learning.


Synthesis of contents


·          Introduction to Astronomy (basic concepts): planet movements, Kepler’s Law.

1.        In their movement around the Sun, the planets describe elliptic orbits, this being one of the focuses of the ellipse.

2.        The areolar speed of each planet is constant (the lineal speech of planets is variable).

3.        The time a planet takes to run a whole orbit; i.e., the revolution values squared of each planet are proportional to the biggest semi-axes cubed of their orbit.

·          To know the main constellations and identify Venus. To learn how to “look at the ski”. Techniques for measuring angles (straight ascension and declination). To use observation tools (projection).

·          To understand the exceptionality of the Transit of Venus.


·          Basic explanations about the topic.

·          Observation “in situ” of the transit.

·          Experimentation with the results of the measurements.

·          Surfing the Internet.

·          Individual work.


·          To value the possibilities that the ski offers us to estimate the distances and to make orientation possible.

·          Interest and curiosity for new scientific advances on astronomy.

·          Being aware of the historic importance of astronomy (navigation, discoveries…)

·          Critical sensitivity about “luminous pollution”, and about the dangers of the observation of the Sun.

·          Cooperation, respect and silence (in workshops and during the field visualizations).




Avda. Pedro Masaveu, 18.

LATITUDE: 43,367             LONGITUDE: -5,833                ALTITUDE: 197 Metres

  None of us could imagine that on June 8 th 2004 in the morning, the day of the expected Transit of Venus, the weather in Asturias would punish us: a dull ski was covering our heads, grey clouds were doing away with our illusion of enjoying the phenomenon. Hours went by and, resigned to failure, while we were disassembling our equipment, a clear ski turned up, the Sun shone, and there was Venus.

This made up for our having got up so early. We closed our umbrellas, dried our equipment and called some more students: “Run, run! We can see it!

We had missed the first internal and external contact, and also the whole trajectory of Venus through the solar disc; but this did not matter at all, for at last we could see it for a moment.

It was 12.40 mp local time (10.50 T.U.). There was little time left and we had to use it up. The rest of the transit, we would just have to imagine it.


Beginning of the observation


-           Astronomic telescope prepared for image projection.

-           Home-made magnifying instrument for image projection.

-           Three chronometers.

-           A notebook to write down the times.

-           A digital camera.

-           Two watches (one with local time and another one with T.U.)

Diary of the session

At 12.40 local time, we began viewing the transit with a conventional telescope which had a paper sheet so that the Sun image could be projected on it. We also used a home-made artefact built up with a glass taken from some binoculars, and a paper sheet whose distance to the telescope could be regulated (this last instrument turned out to be much more practical than the other one). We also utilised three chronometers in order to have triangular measurements by making an average of the three (statistical method). With these simple devices we began the observation.

Once the image was focused, we could observe Venus nearly on the limit of the solar disc. We could not see the whole trajectory, although the small piece we saw helped us deduce the rest of the trajectory.

We took the times of the last interior contact and the last external contact as follows:

- First external contact: we could not observe it for lack of visibility.

- First internal contact: we could not observe it for lack of visibility.

- Last internal contact: 13.04’.30”

- Last external contact: 13.23’.30”

There was not unanimity with the measurements; the three chronometers showed different times, so we decided to make an average of the measurements in order to minimize the error.

The students wrote down the data by using their impressions of the short trajectory they viewed. From the educational point of view, the phenomenon was seen by several secondary school groups of students who visited the experiment by turns. A great deal of the students showed an attitude of incredulity about the experiment. It was difficult for them to believe that what they were watching on the sheet of paper was planet Venus coming through the Sun. One of them even scratched the black point on the sheet of paper (Venus’ projection) thinking that it was just a piece of dust. This shows the scarce knowledge of students on these topics as well as the little attention given to them by the National Curriculum.   

After the observation

Taking into account that the distance between the Earth and the Sun is perfectly known (1 astronomical unit = 149,600,000 km), the scientific interest in this event is limited. What really matters here is the pedagogical interest as a means of arousing the curiosity for astronomy.

 We decide to participate in the VT-2004 Programme even though our experiment was a bit poor due to bad weather. A short time later we were sent the actual results, which were not far away from ours.

 Determination of the A. U.

The calculation of the distance Earth-Sun was made schematically (we had no other positional reference, and the science school text does not cover this kind of calculations). However, the mathematical basis was explained to us by the Mathematics teacher.

The fact that two observers in different parts of the Earth may see Venus’ silhouette in different positions is essential to understand this calculation.

The web page of the Department of Astronomy and Meteorology of the University of Barcelona ( http://serviastro.am.ub.es/venus2004/HTML/contingut/dist_cas.doc) was a great help for us, as it gives the mathematical demonstration we used to understand the calculation.


Comparison of the Transit with an eclipse


The experiment we observed is similar to an eclipse, although the distance between Venus and the Earth, as well as Venus’ relative size, keeps this planet from covering the Sun. That is the reason why we call it a “transit” instead of an eclipse. However, it does look like an eclipse (as is the case of lunar eclipses).

It should be taken into account that an eclipse can easily be seen (just wearing special glasses or filters). Nevertheless, a transit must NOT be observed directly. The explanation is simple: with a transit, the planet covers the solar disc very little, so the Sun light reaches us with full power.


Gallery of images

(Photographic sample taken during the Transit of Venus at the Fundación Masaveu Secondary School in Oviedo)

- Click pictures to look photographs -

Student 1º ESO 

Search the Sun

The transit

Taking notes


long wait

Student 4º ESO


1º Contact

2º Contact

3º Contact

4º Contact


B ibliographical sources :

HERRMAN, Joachim. 1984. Astronomy Atlas . Madrid, Alianza Ed.

Larousse Encyclopaedia

Espasa-Calpe Encyclopaedia.

HACK, Margarita. El universo . Madrid, Labor Ed.

Archae-Astronomy Books by Martin Cano and other authors.

Internet daba base, Ski Guides, Articles, Books of Astronomical Events, different publications by astronomical associations downloaded from the Internet, etc.


Our web page is on our school Internet site. The address is:

www.fundacionmasaveu.com/venus/index3 .html


www.antares.es Astronomy tools
www.ciencianet.com/8jun2004.html Electronical publications Ciencia-Net
www.asaaf.fis.ucm.es/ transitovenus 2.htm ASAAF-UCM Observatorio-UCM
www.roa.es/Efemerides/ transito s/ transito _ venus .html Observatorio Armada de S. Fernando
www.ucm.es/info/Astrof/obs_ucm/ tran_ venus _jun_04/ transito _ venus _junio04.html Madrid University Complutense
www. venus 04.org/ Planeterio de Pamplona
www.infoastro.com/200406/06 venus .html Publicación electrónica  Info-Astro
club.telepolis.com/fgilgon/ venus 2004.html Almeria's Science website
www.iac.es/da/telescopio/ venus 04/ venus 04_main.html Instituto de Astrofísica de Canarias
www.iaa.csic.es/ transito / Instituto de Astrofísica de Andalucía
astrosabadell.org/es/6_amateur/pas venus .asp Agrupación Astronómica de Sabadell
www.planetmad.es/04noticias02.htm Planetario de Madrid
www.nasa.gov/home/index.html NASA's website
www.jccm.es/museociencias/ venus .htm Museum of  CC.de Castilla la Mancha
http://serviastro.am.ub.es/venus2004/HTML/contingut/dist_cas.doc Universidad de Barcelona
www.infoastro.com Astronomical divulgation
www.cite_sciences Astronomical divulgation (Francia)