Transit of Venus 2012: “marvel at the solar system in motion”

As I mentioned back in March, tonight one of the rarest predictable astronomical events will occur – a transit of Venus[I’m washing my hair! – Ed]  What hair?  ANYhoo… Since the invention of the greatest human innovation, the telescope, at the beginning of the 17th century, not by Galileo, there have been only 7 such transits.  The next time it will happen will be on 11 December 2117. 

Nasa’s Sun-Earth Day website will be providing a live web cast during the more than 6 and a half hour transit, which begins just after 11pm [BST].  But that’s just one of the options.

There’s also a Horizon Special on The Transit of Venus tonight, BBC 2 at 9pm.  And an online, but unembeddable, clip of presenter Liz Bonnin explaining why it’s so rare an event.

The BBC’s spaceman, Jonathon Amos, has a good report on the historical and contemporary significance of the transit.

The phenomenon has particular historical significance. The 17th- and 18th-Century transits were used by the astronomers of the day to work out fundamental facts about the Solar System.

Employing a method of triangulation (parallax), they were able to calculate the distance between the Earth and the Sun – the so-called astronomical unit (AU) – which we know today to be about 149.6 million km (or 93 million miles).

This allowed scientists to get their first real handle on the scale of things beyond Earth.

The first person to predict a transit of Venus – the 6 December, 1631, event – was Johannes Kepler, but he died before it occurred.

Jeremiah Horrocks, the young English astronomer, was probably the first to record the phenomenon when he and his friend, William Crabtree, made separate observations of the passage on 24 November, 1639.

By the time the transits of 1761 and 1769 came around, they had become major scientific events. Expeditions were despatched all over the globe to get the data necessary to calculate the AU.

One such expedition was undertaken by Captain James Cook, whose epic voyage in the Endeavour took in the “new lands” of New Zealand and Australia.

Transit-hunting has proven a successful method in the hunt for exoplanets.

From TransitVenus on YouTube

And from SunEarthDay on YouTube, part1 of a 6 part series of clips highlighting the history and the science behind the transit and the culture and history of Hawaii.  As you’d expect, one of Those [Royal Society] Guys makes an appearance…

And from the astronomical unit to the extent of our star’s influence, and a billion stars revealed.

Space is big.

Adds Here’s a stunning short video from NasaExplorer using images from LASCO C3 coronograph on board the SOHO spacecraft.

Update Live video stream from NasaTV.

Streaming by Ustream

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  • lamhdearg2

    Cloudy with further outbreaks of rain. The rain will become mostly confined to Antrim and Down later with drier weather developing elsewhere. A mild night with light winds.” BBC weather belfast.

  • Pete Baker

    Adds Here’s a stunning short video from NasaExplorer using images from LASCO C3 coronograph on board the SOHO spacecraft.

  • Pete Baker


    Some people don’t have to worry about the weather.

  • lamhdearg2

    “Some people don’t have to worry about the weather.”
    solar storms?.
    it is a pity, the weather ,for this like the jubilee and easter, is running a week late,

  • lamhdearg2

    pete another forecast has clear skys over ulster around dawn, will this be too late?, is it something that can be seen via sunglasses?.

  • sonofstrongbow

    If you have access to an eclipse lens you could use that. Otherwise best to go for a projection of the sun through a lens, binoculars would do, onto a white surface.

    Let’s hope the weather plays ball.

  • lover not a fighter

    The bbc have been pushing this with the three female experts/presenters.

    I hope its a good show and no harm at all to have a few females. This stargazing stuff does seem a bit male lobsided on tv at least.

  • sonofstrongbow

    Given the subject planet going with the ladies appeals even to my sexist prejudices 😉

  • Robert Stawell Ball, observing the transit before last:

    I venture to record our personal experience of the last transit of Venus, which we had the good fortune to view from Dunsink Observatory on the afternoon of the 6th of December, 1882.

    The morning of the eventful day appeared to be about as unfavourable for a grand astronomical spectacle as could well be imagined. Snow, a couple of inches thick, covered the ground, and more was falling, with but little intermission, all the forenoon. It seemed almost hopeless that a view of the phenomenon could be obtained from that observatory; but it is well in such cases to bear in mind the injunction given to the observers on a celebrated eclipse expedition. They were instructed, no matter what the day should be like, that they were to make all their preparations precisely as they would have done were the sun shining with undimmed splendour. By this advice no doubt many observers have profited; and we acted upon it with very considerable success.


    We succeeded in obtaining sixteen measures altogether; but the sun was now getting low, the clouds began again to interfere, and we saw that the pursuit of the transit must be left to the thousands of astronomers in happier climes who had been eagerly awaiting it. But before the phenomena had ceased I spared a few minutes from the somewhat mechanical work at the micrometer to take a view of the transit in the more picturesque form which the large field of the finder presented. The sun was already beginning to put on the ruddy hues of sunset, and there, far in on its face, was the sharp, round, black disc of Venus. It was then easy to sympathise with the supreme joy of Horrocks, when, in 1639, he for the first time witnessed this spectacle. The intrinsic interest of the phenomenon, its rarity, the fulfilment of the prediction, the noble problem which the transit of Venus helps us to solve, are all present to our thoughts when we look at this pleasing picture, a repetition of which will not occur again until the flowers are blooming in the June of A.D. 2004.

  • Pete Baker

    Wonderful stuff, Nicholas!

    No doubt as they approach the next transit on 11 December 2117 observers will, once again, be looking at our star, making their preparations, and hoping for clear skies.

  • Pete Baker

    Update Live video stream from NasaTV.

    Streaming by Ustream

    Transit Begins!