Venus Transit Approaching
In some hours, at midnight between Friday and Saturday, ten more countries will join the European Union. The EC-supported Venus Transit 2004 (VT-2004) programme is active in almost all of these, with VT-2004 National Nodes already established the Czech Republic, Hungary, Malta, Poland, Slovenia and Slovakia; more are likely to follow soon. The organisers include the Astronomical Institute of the Academy of Sciences of the Czech Republic and the next VT-2004 meeting will be held near Prague on May 7-9 (see below).
Venus Moves Closer
"Catching up" with the Earth in its orbit (see VT-2004 Animation C), Venus will be placed exactly between the Sun and our planet in the morning of June 8, the day of the extremely rare event, known as a "Venus Transit". Observers in the eastern hemisphere will be able to see Venus as a black spot slowly crossing the solar disk during about 5 1/2 hours.
Until then, Venus orbital motion takes it closer to us and this planet will therefore become apparently larger in the sky. Today, April 30, the distance between the Earth and Venus is 69 million km; on June 8, it will be 43 million km only. Today, its disc subtends the same angle as a 1 Euro coin seen at a distance of 140 m (35 arcsec); on June 8, that distance will be only 85 m (57 arcsec).
This effect is nicely illustrated on the photo which combines five images of Venus, obtained by Hans-Goeran Lindberg between April 8 and 27 from his observatory in Sweden. As can be noticed, we arealso gradually seeing Venus "from behind" - the phase is rapidly changing and Venus’s crescent will become more and more narrow during the coming weeks.
Earth Transit on May 4!
Quite a few photos were submitted to the VT-2004 Photo archive that show the close approach in the sky of the Moon and Venus on April 22-23.
The Moon will also be an interesting object next Tuesday (May 4) when it passes through the Earth’s shadow during a "total lunar eclipse". This kind of celestial event is much more common than a Venus Transit and will offer observers in Europe, Africa and Asia who have clear skies a fine view of a dark red Full Moon.
If you were standing on the surface of the Moon at that time, you would see the Earth move in front of the Sun and block the sunlight - this is in fact an "Earth Transit"! However, some sunlight is deflected through the Earth’s atmosphere and will be seen as a glowing ring of light around our planet. This is also the reason why the Moon will appear very red during the eclipse - blue light from the Sun is dispersed much more in the Earth’s atmosphere than red light (that is also why our sky is blue during daytime). Accordingly, more red than blue light will reach the Moon during the eclipse.
More information about the lunar eclipse may be found at many websites, e.g. those of NASA - Eclipse home page (F.Espenak) or the IMCCE (in French).
VT-2004 Observing Campaign
As of today, over 300 observers from all continents except Antarctica (where the transit will anyhow be essentially invisible) have registered with the VT-2004 Observing Campaign. They will attempt to measure the exact times when Venus passes the Sun’s limb on June 8 and submit their data to the VT-2004 Centre via the corresponding webpage. Here, all observations will be combined in an historical re-enacting of the measurement of the distance from the Earth to the Sun. More news will soon follow about this unique undertaking.
VT-2004 Amateur Meeting
On May 7-9, 2004, about 40 amateur astronomers from almost as many countries will meet with the members of the VT-2004 Interntional Steering Committee in Brandys near Prague (Czech Republic). This encounter will serve to discuss in depth how observations of the Venus passage can best be done. The meeting will also help to find ways to further stimulate the participation by amateurs and other interested persons in the many activities surrounding the Venus Transit and the VT-2004 project. A report on this meeting will follow in VT-2004 Press Communication No. 3 and the Amateurs’ webpage will be updated right thereafter.
Live Images of the Transit on June 8
The system by which live images from many different observing sites will be displayed at the VT-2004 Central Display during the transit on June 8 is now being set up. Contacts have been made with a number of strategically located professional observatories and it is also foreseen that many public and private observatories will provide images on this occasion. In view of the expected, enormous traffic volume on the Internet, VT-2004 has contracted with the Akamai company to use approximately 200 mirror sites all over the world beginning the day before the transit. This should ensure easy access to everybody, even in the most intense period.
More Educational Material
The Students and Teachers Webpage has been updated and now contains more useful and interesting material for schools, associations, etc., suitable for different age levels.
Of certain public interest will also be the VT-2004 Quiz by means of which you may test your knowledge about the Venus transit. The correct answers are given at the end, together with onward links towards the related Information Sheets.
Richard West | alfa