Transit of Venus on June 5-6, 2012On June 5-6, 2012, Venus will pass in front of the Sun. The 2012 transit of Venus will be the last chance to view this phenomenon for over 100 years.
The transit of Venus explainedDuring the transit, Venus passes between Sun and Earth. The planet becomes visible from Earth as a small dot against the Sun's disk.
Protect your eyes during the transit of Venus!
Although Venus is almost four times larger than the moon, it blocks a much smaller portion of the Sun's face than the moon does during a solar eclipse. This is because it is much further away from Earth.
Venus is the second planet from the Sun, Earth is the third. On a clear night Venus can also be seen as a bright “star” in the sky, especially shortly after sunset or before sunrise. This is why it is also referred to as “evening star” or “morning star”.
When is the transit in my city?
Depending on the observer's actual geographic location, times will differ by up to several minutes (see table below to the right).
Note: Times are stated in Universal Time - a time standard based on the Earth's rotation. Click on the links to see corresponding local times worldwide.
- June 5, 22:09:29 UT: the planet's first contact with the outer rim of the Sun's disk.
- June 5, 22:27:26 UT: Venus becomes fully visible in front of the Sun.
- June 6, 01:29:28 UT: moment of “greatest transit” (the closest Venus appears to the center of the Sun's disk).
- June 6, 04:31:30 UT: Venus reaches the opposite side of the Sun's rim
- June 6, 04:49:27 UT: the planet completes its transit across the Sun's disk.
Can I see the transit?The whole transit will be visible in the following locations:
- Northwestern North America (e.g. Alaska and north-western Canada)
- Eastern Australia
- New Zealand
- Northern and eastern Asia (e.g. Japan, eastern China, Sibiria, Mongolia)
- Parts of Southeast Asia (e.g. Philippines, eastern Indonesia)
- Western Pacific
- Mainland U.S.A.
- Most of Canada
- Central America
- Northwestern South America
- Eastern Pacific
- Europe (except Portugal and western Spain)
- Western Australia
- Western and southern Asia (e.g. India, Thailand, Iran, Turkey)
- Eastern Africa (e.g. Egypt, Kenia, Madagascar)
- Indian Ocean
How often does this happen?The alignment Earth - Venus - Sun has only occurred 7 times since the invention of the telescope: in 1631, 1639, 1761, 1769, 1874, 1882, and 2004.
The phenomenon can be experienced in recurring intervalls of 8 years, 121.5 years, 8 years, and 105.5 years. The last occurrence was 8 years ago, the next one will be in 105.5 years - on December 11, 2117.
Protect your eyesLike observing solar eclipses, viewing the Venus pass before the Sun requires proper eye protection. The sun’s photosphere emits intense infrared and ultraviolet (UV) radiation. Just as UV radiation causes sunburn to skin, it can also damage the retinas in the eyes - but it does so at a much faster rate. The human eye can suffer permanent damage if it is exposed to direct sunlight for a few seconds.
The easiest and cheapest option to protect your eyes while watching the transit of Venus is to buy solar shades, which normally cost around 1 USD.
Note: Information on the transit courtesy of Fred Espenak, NASA/Goddard Space Flight Center.