Transition Of Venus Today

Posted by Gold FM on 06/06/2012

transit of venus ap 670

Today is an auspicious occasion for star gazers and is particularly significant to New Zealanders and the Coromandel Peninsula.

We will be able to view the transit of the planet Venus across the sun (if the weather behaves) for the first time since 1796.

James Cook was sent to the Pacific over 200 years ago with orders to observe and document the transition of the planet Venus, and helped to create our history.

A skilled cartographer and mathematician, Lieutenant James Cook left Plymouth, England on the 16th of August 1768  bound for the Pacific by royal command of King George the III to observe and document the transition of Venus. He reached Tahiti in April, in time to observe the transit on June the 3rd 1769 . It was hoped that the observation would allow the distance between Venus and the Sun to be calculated. Unfortunately the equipment of the day did not lead to conclusive results.

After the observation was completed Cook opened sealed orders detailing the 2nd part of his voyage; to search the Pacific for the believed to be richly endowed continent Terra Australis. With the help of a Tahitian navigator, who had extensive knowledge of the Pacific geography, Cook and his crew became the second Europeans to arrive in New Zealand waters, landing at Cook's Beach, Whitianga, and then observing the transition of the planet Mercury from Mercury Bay, hence the name, on November the 9th 1769.

Today's transit won't be visible again until 2117.

Astronomers all over the world will be gazing into the heavens today, more than half the world will get to see an exceedingly rare event: a transit of Venus crossing the face of the sun at inferior conjunction. A transit of Venus is among the rarest of astronomical events, rarer even than the return of Halley's Comet every 76 years. Only six transits of Venus are known to have been observed by humans before.

It's very important that the transit is not viewed with the naked eye. Even sunglasses won't offer adequate protection for eye damage.

The safest way is to project the image of the Sun onto a suitable screen. Alternatively a suitable, specially designed, Solar filter may be placed in front of the telescope.

How To Make A Simple Solar Viewer

Make a simple version of a solar  viewer with two thin but stiff pieces of white cardboard. Paper plates work well. Punch a small, clean pinhole in one piece of cardboard and let the sunlight fall through that hole onto the second piece of cardboard, which serves as a screen, held below it. An inverted image of the sun is formed. To make the image larger, move the screen farther from the pinhole. To make the image brighter, move the screen closer to the pinhole. Do not make the pinhole wide or you will only have a shaft of sunlight rather than an image of the crescent sun. Remember, this instrument is used with your back to the sun. The sunlight passes over your shoulder, through the pinhole, and forms an image on the cardboard screen beneath it. Do not look through the pinhole at the sun.

If you'd like to view the transit webcam from NASA follow this link.