Venus Transit To Be Visible On June 5-6, 2012

Transit Of Venus 2012 Path (NASA)

A Venus Transit, which takes place when Planet Venus passes directly between the Earth and the Sun, will be visible on June 5-6, 2012. But considering the small size of the planet, the Transit is only seen as a small black disk moving across the face of the Sun.

The transits of Venus occur in pairs with more than a century separating each pair. Since the invention of the telescope, there have been only eight of such events that have occurred - 1631, 1639, 1761, 1769, 1874, 1882, 2004 and the upcoming one this June 2012. The 2004 and 2012 transits form a contemporary pair separated by 8 years. The next two transits of Venus will occur on 2117 and 2125.

The principal events occurring during a transit are characterized by contacts, similar to the contacts of an annular solar eclipse. They are as follows:

• First contact (external ingress): Venus is entirely outside the disk of the Sun, moving inward
• Second contact (internal ingress): Venus is entirely inside the disk of the Sun, moving further inward
• Third contact (internal egress): Venus is entirely inside the disk of the Sun, moving outward
• Fourth contact (external egress): Venus is entirely outside the disk of the Sun, moving outward.
• A fifth named point is that of greatest transit, when Venus is at the middle of its path across the solar disk and which marks the halfway point in the timing of the transit. 

Wednesday's Venus Transit, with all its four contacts, will be visible in Greenland, North and Central America, Pacific Is., Australasia, Asia (including the Philippines), E. Africa and most of Europe.

In the Philippines, it can be observed from 6:09 in the morning until 12:49 in the afternoon on Wednesday, June 6.

One should take precautions in watching the Sun during these hours as staring at it without precaution can damage one's retina. The safest manner is to project the image of the Sun through pinholes, telescopes or binoculars onto a screen or by using a filter to shield the naked eye.