Transit of Venus,Captain Cook

 Today we had to complete 2 tasks for reading and this was about Captain Cook and the Transit Of Venus. 

 Transit of Venus -                              

Like Earth, Venus travels around the sun but it follows a closer orbit.

 Sometimes the planet’s path takes it between the earth and sun. Whenever this happens, we can see Venus move across the sun’s face. This is called a “Transit”. Even though Venus Transits are rare they are also predictable. They are located in pairs but at least 8 years apart but separated by long gaps which either consist 105 or 121 years. 

In 1716, a English astronomer called “Edmond Halley” worked out a way to use the transit of Venus to calculate the distance between Earth and Sun.

 

Around the early 18th century, people didn’t really have this information.

Over a hundred scientists watched the transit of Venus in 1761, but some couldn’t really take the accurate measurements because there was bad weather. But luckily they tried once again after 8 years (1769) .

 (But if they were unsuccessful they would have to wait another 105 years.)

So the 1769 transit was watched from various places like Canada, Norway and Russia. Then they combined the results from 1761 and their successful transit together. After a few years they discovered that the Earth is at least 93, 727, 000 miles away from the sun.

So if we use our modern day technology preferably a radar we would know that it’s around 149, 600 , 000 kilometers.

(Which one do you think was better? 1761/1769 or now?)