Video: Stargazers and astronomers have been observing the planet Venus crossing between the Earth and the Sun

As anticipated, the stargazers in several regions of the Earth had once-in-a-lifetime opportunity to view the rare celestial phenomenon of Venus moving across the face of the Sun. The event is also so important for scientists — especially astronomers — that the next time Venus makes a similar transit will be only after 105 years.

The planet touched the edge of the Sun’s disc at 22:09 GMT on Tuesday and left the disc at 04:49 GMT. The next transit will be seen only on 11th December 2117, when possibly and unfortunately, none of the people who observed the event now may live long enough to witness it.

The Venus transits take place in pairs of events with a gap of approximately eight years because such transits occur only four times in 243 years (224.7 Earth days to be precise). After the invention of the telescope, such seven pairs of events took place in 1631 and 1639, 1761 and 1769, 1874 and 1882, the only and last such pair of this century being in 2004 and 2012.

Interestingly, the gap between the years of one occurrence of a pair and the other is 8 years. Hence, the next pair of Venus transits will take place in 2117 and 2125.

The present crossing of Venus across the sun is of great significance from the scientific point of view because earlier the scientific equipments and knowledge to study such events were rather crude or not as developed as in the present times.

The transit of Venus also gave a chance to scientists to conduct experiments to probe the possibility of the existence of Earth-like planets elsewhere in the Milky Way galaxy, and the existence of life elsewhere in other galaxies. They also can probe the Venusian atmosphere that is structurally and compositionally very complex.

About 96.5% of the gases in the atmosphere of Venus are carbon dioxide (CO₂) and most of the rest is nitrogen with a very miniscule percentage of other gases. Sometimes the Venus atmosphere is covered with an opaque and dense layer of reflective clouds of Sulphuric Acid (H₂SO₄) because of which its surface is not clearly seen from the space in visible light.

Scientists have come to the conclusion that once the surface of Venus had oceans and water bodies but now its terrestrial structure is desert-like with very high temperatures soaring to about 460 °C.

The gases rising up on the atmosphere of Venus do not get into cyclic conversions such as carbon cycle, water cycle, etc. because they rise up and get mixed into the interplanetary space because Venus has no planetary magnetic field, and the free hydrogen in its atmosphere get swept into space by blazing solar winds.

This could be one of the possibilities of life not existing on Venus despite its several similarities to the Earth, despite the two planets having almost the same size, orbit, gravity, chemical composition, and at about the same distance from the Sun. For these similarities, it is often referred to as the Earth’s Sister Planet.

The planet Venus is named after Goddess Venus, the mythological Roman goddess of love and beauty, whose Greek equivalent is Aphrodite. This also indicates that the ancient Romans and Greeks too used to study Venus and associated it with life, love, intrigues and beauty of Goddess Venus.

Venus is the third brightest celestial body visible to humans after the Sun and the Moon, and hence it is one of the first planets of our solar system that attracted human observation. Venus is also known as the Morning Star or the Evening Star because it appears the brightest just before sunrise or just after sunset.

During its transit across the face of the sun the planet was visible as a small black circular dot and it took about six hours and thirty minutes to come out.

Among the most preferred Venus gazing sites were locations in Central America, the northern South America, southern North America, Canada, the Arctic region, Europe including the British Isles, the Middle East, eastern Africa, East Asia the western Pacific and Australia.

Hawaii in the United States turned out to be one of the best places to see the whole event with the Hawaii University’s Institute of Astronomy setting up telescope stations on the world famous Waikiki beach.

Some of the best photographs of the Venus event were provided by NASA’s Solar Dynamics Observatory (SDO), a special observatory positioned at a distance of over 36,000 km above the Earth.

After the invention of the telescope at the beginning of the 17th century, Tuesday’s Venus transit is only the eighth and the only event so far with a spacecraft (SDO) near Venus when it occurred.