Transit of Venus

On June 8, a rare celestial event, the transit of Venus, was visible over parts of Europe and most of Asia including India. As Mercury and Venus are much farther away from the Earth (when compared to moon), they project a small dark spot which moves across the brilliant solar disc for several hours during their transit. On June 8, it was Venus, which projected a small dark spot across the Sun’s disc. By mid morning, as per Indian Standard Time, Venus touched the solar disc and till late in the afternoon it could be seen (from India) moving at a snail’s pace as a black dot silhouetted against the bright solar disc.

The progress of the Venus transit as seen in the High resolution H-alpha solar images.

On the special occasion of the Venus Transit on June 8, 2004, the Udaipur Solar Observatory (USO) had set up a coelostat on the southern terrace of its main building, feeding sunlight into a convex lens. The image formed by this lens was magnified by another lens and projected on a screen. Thus, a solar image of about 60.8 cm in diameter was obtained. The first contact was observed by all viewers. A group of children from North Eastern States had arrived to view the transit. These children made simple observations like noting time and calculating the lateral speed of Venus. Professor U R Rao, Chairman, Council of Management, Physical Research Laboratory, addressed the school children and spoke about the excitement of science.

In spite of clouds, USO could obtain specklegrams of the Venus image. Another experiment was conducted on the island (in Lake Fatehsagar) in which the transit was observed in the light of Hydrogen-alpha at two different spatial resolutions. This is the first time that the transit has been recorded in this spectral line.

Large Crowd that gathered to watch the transit of Venus in the premises of Jawaharlal Nehru Planetarium

ISRO supported the Jawaharalal Nehru Planetarium at Bangalore to undertake several space science popularisation events on the occasion of this rare celestial phenomenon. These included a special video presentation on the phenomenon of Transit, arrangements for viewing the transit through telescopes fitted with special filters and regular briefing. Thousands of students and the general public visited the planetarium to view transit and to understand the phenomenon.