Transit of Venus

RSS

If you missed it you’ll have to wait another 105.5 years for the next ‘transit’ of Venus across the face of the sun. Prior to today’s event the last one was in 2004 and before that it was 1882. In astronomical history the transit was a huge deal as it provided a rare opportunity to define the Astronomical Unit (AU), or the distance from the sun to Earth. Dubbed a celestial yardstick, the AU helps astronomers measure distances among the planets and to link them to the stars beyond.

In 1716, the astronomer Edmond Halley calculated that the AU could be worked out if observers around the world timed the passage of Venus across the sun. Halley predicted the best spots around the world where the transits could be seen and throughout the 1700s and 1800s explorers fanned out across the globe to fulfill his quest. According to a website dedicated to the phenomenon, the mounting of several expeditions to view the transit in 1761, in the midst of the Seven Years War, marked one of the first times several countries co-operated to answer one of the main scientific questions of the day.

Thanks to my son Greg, who helped me rig up binoculars and a piece of card to record the event in California this afternoon, here is a shot of Venus on its way across the sun. Note the sunspots in the image.  

 

Please or Register to post comments.

What's On Space?

On Space

From The Archives

Aviation Week is approaching its 100th anniversary in 2016. In a series of blogs, our editors highlight editorial content from the magazine's long and rich history.

 

Aug 27, 2015
blog

Aviation Week Lifts Veil On Boeing B-52 Bomber (1952) 12

In 1952, Aviation Week provided the first details on the new Boeing B-52 bomber....More
Aug 14, 2015
blog

Bonanza Travel Pays 3

The legendary Beechcraft Bonanza has an impressive production record, so perhaps the marketers back in 1949 were onto something when they coined the phrase "Bonanza travel pays."...More
Aug 14, 2015
blog

Venerable Boeing 727 Prototype To Fly Again 28

The most famous 727, the prototype aircraft which would join United as N7001U, was delivered to the airline in October 1964 having served its time as a Boeing test aircraft....More
Aug 13, 2015
blog

Aviation Week And The Bomb

Aviation News did not predict how nuclear weapons would change the world. But neither did anyone else....More
Aug 13, 2015
blog

Collins Radar Takes The Ups And Downs Out Of Flying

Turbulence? Rockwell Collins had a solution for those bumpy rides in the early 80s with its WXR-700 Doppler Weather Radar....More
Blog Archive
Penton Corporate

Sponsored Introduction Continue on to (or wait seconds) ×