The Venus
Transit 2004

On June 8, 2004,
Venus - the Earth's sister planet - passes in front of the
Sun as seen from the Earth. This very rare event (no living person
has ever seen one!) lasts about 6 hours and will be
visible from most of Europe, Africa and Asia.

It will most certainly generate unprecedented attention
from the media and the public, not just in these areas,
but all over the world.

This website describes the VT-2004 project that is
related to this celestial event and which
aims at transforming curiosity into knowledge and interest in
science through a broad set of actions. It has been launched by the
European Southern Observatory
(ESO) and
the European
Association for
Astronomy Education (EAAE), together with the href="http://www.imcce.fr/">Institut de Mécanique
Céleste et de Calcul des
Éphémérides (IMCCE) and the href="http://www.obspm.fr">Observatoire de Paris in
France, as well as the href="http://www.asu.cas.cz">Astronomical Institute of
the Academy of Sciences of the Czech Republic.

The VT-2004 programme is supported by the European Commission
in the frame of the European Science Week 2004.

Read the VT-2004 Latest News and
follow the development of this large-scale programme!

The VT-2004 project invites active participation
of all interested individuals (including teachers, students,
amateur astronomers, etc.) and educational institutions
(planetariums, public observatories, science centres, etc.).
It will provide comprehensive information about the wide scientific,
technical, social and historical aspects of this rare event.

It encourages and will coordinate the making of real-time
measurements of one
of the most fundamental astronomical parameters, the distance
from the Earth to the Sun. It explains the relation of this event
to a current front-line research area, the search for extra-solar
planets by the transit method; the only one which, in the
near future, will be able to discover Earth-size planets and thus
possibly, alien habitable worlds.

The VT 2004 project promotes international collaboration
throughout a large part of the world, by observing the same
rare celestial event, debating it via the web and adding local
observational contributions to a large, common database. Real-time
feed-back via the web and the media will ensure that this will become
an absolutely unique public event.

VT-2004 strives to establish a large, international network
of educational institutions that will be actively involved in the
Venus Transit event. A list of these institutions and organisations
is available here, with the related links.

The present website is in the process of being built up
and is still in a provisional format.
When ready in early 2004, it will provide access to
a wealth of related information in many (European) languages
about many different aspects (scientific, technical,
historical etc.) of the event itself and also its implication
in the current search for life outside the Earth.

The entire cosmic
distance scale, stretching from our neighbourhood in the solar
system to the remotest galaxies in the Universe, rests on the
mean distance from the Earth to the Sun, also known as 1
Astronomical Unit (AU).

By performing a rather simple observation, everybody who
reads the easy-to-comprehend instructions at this website will be
able to contribute actively to the measurement of this
fundamental distance.

VT-2004 thus provides a unique opportunity to participate
in a great experiment, during which one of the first, accurate
historical measurements of
a distance beyond the Earth will be re-enacted in public.

Read here
about the background and ideas for this ambitious programme, and
later also about the preparations and the suggested observations,
as well as what will happen on June 8, 2004, during the event
itself. We will also explain how your
measurements, together with those of many other people on three
continents, will be used to determine the distance to the
Sun!

We know the correct answer - astronomers have already measured
1 Astronomical Unit to be exactly 149,597,870 km. But how
close to this will be the new value, determined during this Venus
Transit in 2004? And how accurate will it be?

The Venus Transit is
like an (annular) solar eclipse, except that the angle subtended
by the disk of Venus is much smaller than that of the Moon.
Thus, during the transit Venus will be seen as a small dark dot that
moves across the solar disk.

Before you read on - be sure to note this important
message about safety:

There is no danger if
you follow the safety
instructions that will be described at this website. However,
please note that the VT-2004 organizers
will accept no responsibility for
any injuries that may be caused by participation in this
programme.

With the event itself still many months into the future, this VT-2004
programme is now in the process of being put together. In order
to make it easier to follow this process and to learn about the
current stage of the preparations, a number of webpages are gradually
being built up. Among these, the following will be particularly
useful:

• The Background
  - General information about the astronomical event and its
  historical aspects, related scientific, technological and
  sociological issues, etc. A place where the Venus Transit
  event on June 8, 2004, is put into the full context and
  where you will learn all about
  the true significance of the Venus Transit!



• Associated Institutions -
  the steadily growing network of institutions and organisations
  that are associated with VT-2004. Among them are
  amateur astronomy associations and clubs, public observatories,
  planetaria, science centres, etc.



• How to Participate
  - here you can (later) read about how individuals and groups
  may join VT-2004 by performing observations of the Venus
  Transit on June 8, 2004, which preparations are necessary, etc.



• Observations -
  how are those measurements made? What do you have to
  watch out for to ensure that they are sufficiently accurate
  to provide a useful contribution to the overall goal of this project,
  i.e., to determine the distance to the Sun?



• Day of the Transit -
  what happens when on June 8, 2004? How can you send your
  observations to the VT-2004 programme office?



• Central Display - here
  you may follow the event via the web and see the progress
  of Venus on the solar disk via webcam. The main display
  will keep you informed about the current results of the
  observations made by the participants. Ask questions
  to the scientists and receive answer in near-real time!



• Frequently Asked Questions
  - look here if you need assistance!



• Useful Weblinks
  - other sites on the web with related, useful information.

The other inner planet in the solar system, Mercury, also
traverses the face of the Sun from time to time, in fact much
more often than Venus. But Mercury is much smaller than Venus
and Mercury Transits are more difficult to observe.

The Mercury Transit
event on May 7, 2003, was a great success, with active participation
of professional and amateur astronomers everywhere in the wide
geographical area where this phenomenon could be seen. The weather
was also very co-operative.

The comprehensive href="mt-2003/mt-intro.html">ESO website was in high
demand during the event, in particular the href="mt-2003/mt-display.html">photos and the href="mt-2003/mt-display-hotline.html">hotline.
This site also includes a lot of useful background information,
with special sheets for href="mt-2003/mt-education.html">students and teachers
in many different languages.

This event became a real "rehearsal" for next
year's Venus Transit and the VT-2004 organisers
are taking into account the "lessons learned".

If
you have questions in connection with the VT-2004 project,
you may contact the organisers via email at href="mailto:vt-2004@eso.org?subject=VT-2004-CONTACT">vt-2004@eso.org.