See Venus passing in front of the Sun!
Venus is the Earth's nearest planetary neighbour. It draws twice as close to our planet as Mars ever does. In terms of size and mass, Venus is Earth's twin and yet it has evolved in a radically different manner, with a surface temperature hotter than a kitchen oven and a choking mixture of noxious gases for an atmosphere.
Venus transit 8 June
Before any attempt to look at that event, read carefully the safety rules to protect your eyes. You can find them in particular on the ESO web pages. The planet Venus will appear to traverse the southern half of the Sun, moving from left to lower right.
Times of Venus transit ingress and egress depend on the location on Earth. From these differences one can determine the distance to Venus and the Sun. 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 the Astronomical Unit (AU), which was first determined thanks to historical Venus transit parallax observations.
Once the distance of solar system targets was calibrated, apparent sizes could be translated into real sizes. This allowed comparing and understanding the physics of planets, objects and processes in the solar system. It was the next step before more complete telescopic studies, and then exploration with deep space probes.
Times of Venus transit ingress and egress in U.T. on 8 June 2004 depending on location:
|Place||Ingress interior contact||Ingress exterior contact||Egress interior contact||Egress exterior contact|
|Perth||05 09 48.7||05 28 16.4||(after sunset)|
|Oslo||05 19 01.8||05 39 00.1||11 02 52.5||11 22 18.1|
|Berlin||05 19 43.7||05 39 21.5||11 03 28.3||11 22 47.6|
|Leiden||05 19 51.7||05 39 33.7||11 03 52.1||11 23 13.1|
|London||05 19 54.8||05 39 39||11 04 06.0||11 23 27.9|
|Paris||05 20 03.0||05 39 45.2||11 04 18.3||11 23 37.5|
|Rome||05 20 12.8||05 39 46.7||11 04 34.8||11 23 46.0|
|Madrid||05 20 24.4||05 40 07.5||11 05 30.1||11 24 45.1|
|Washington||(before sunrise)||11 06 03.2||11 25 53.2|
Many events are organised in the world to observe this unique phenomenon. Visit the ESO web pages to find many of them by country (more than 40 countries in Europe referenced).
Solar system exploration
Currently, ESA probes have been launched, or will be launched soon, to study the Sun, Moon, Mars, Venus, Mercury, Saturn and its moon Titan. Astronomical spacecraft will search earth-class planets by detecting transiting planets around distant stars.
- Venus Express
Venus Express will be ESA's first mission to Venus. Venus Express's science objectives are to study the atmosphere, the plasma environment, and the surface of Venus in great detail. It is scheduled for launch from the Baikonur Cosmodrome in Kazakhstan in November 2005. Its journey through space will last 153 days. Once it is captured by the Venusian gravity, Venus Express will take 5 days to manoeuvre into its operation orbit, looping around the poles of the planet. At its closest, it will reach an altitude of 250 kilometres and at its furthest, it will be 66 000 kilometres away from the planet. The mapping mission is due to last for 2 Venusian days, about 500 Earth days.
- The Sun and SOHO
The Venus transit event gives also the opportunity to observe the Sun that controls the solar system, and our lives. The same precautions as during partial eclipses have to be taken. The Solar and Heliospheric Observatory (SOHO) is stationed 1.5 million kilometres away from the Earth. There, it constantly watches the Sun, returning spectacular pictures and data of the storms that rage across its surface. SOHO's studies range from the Sun's hot interior, through its visible surface and stormy atmosphere, the corona and the solar wind, and out to distant regions influenced by solar radiation and wind. The SOHO mission is a joint ESA/NASA project. Because of its location, SOHO will see the transit of Venus, not over the visible disk, but over the outer solar corona.
- Exoplanetary transits
COROT will contribute to the search for habitable, Earth-like planets around other stars. It will do this by detecting planets as they pass in front of their parent stars, blocking some of the light. From the ground, the only planets detected around other stars have been giant gaseous worlds (Jupiter-like planets), over 10 times the diameter of the Earth. Above the distorting effects of the atmosphere, COROT will be the first spacecraft capable of finding worlds made of rocks, smaller than the gas giants but several times larger than the Earth, itself the biggest rocky planet in the Solar System. Such planets would represent a new, as yet undiscovered, class of world that astronomers believe exists. With COROT, astronomers expect to find between 10-40 of them, together with tens of new gas giants. After COROT, exoplanet transit search missions with larger telescopes and sophisticated modern detectors surveying million stars will be necessary to detect Earth-sized worlds, which typically block less than one hundredth of a percent of the starlight.
Darwin is a flotilla of four spacecraft that will search for Earth-like planets and analyse their atmospheres for the chemical signature of life. The light from telescopes on board the four spacecraft will be combined to simulate a mirror equivalent to 80 m in space, in order to distinguish the light from the exoplanet, one million times fainter than that of the parent star.
ESA Research and Scientific Department
+ 31 71 565 3574 (c/o Samira Ihaddadene)
Bernard Foing (chief scientist)
Hakan Svedhem - Venus Express
Bernhard Fleck/Paal Brekke - SOHO
Fabio Favata - Eddington
Malcolm Fridlund- Darwin
Science Education Support: Anne Brumfitt
ESA Education Department: educationesa.int
Click on site name to open it in a new window:
- Venus Transit 2004 website at ESO
- Historical observations
- Venus and Earth compared
- ESA Science Missions
European Southern Observatory (ESO) Education web pages
La Main à la pâte (primaire - 6 to 11 years old)
Site officiel français - fiches pédagogiques
If you are around Nice you can also go to the Astrorama.
University of Essen
Astrophysikalisches Institut und Universitäts-Sternwarte Jena
Kanzelhoehe Solar Observatory, University of Graz, Austria