Transit of Venus

Ever since Lieutenant James Cook (Yes the Captain of the Endeavour) traveled south to observe the Transit of Venus, those Southern Continent Dwellers (namely the "Aussies") have taken great interest in this celestial event.  However, what is a “Transit”, I hear you ask.  To explain in the plainest terms, it is where one celestial body passes across another, making it visible from earth.

A very short history:

First seen in 1639 by Jeremiah Horrocks, the importance of the transit has become quite a stepping stone to our understanding of the rate and way the world turns as well as our ability to calculate distances between earth and other masses – namely planets. 

Observations of the transits of Venus became scientifically important when in 1716 Edmund Halley proposed that observations from different locations on the Earth could be used to determine the distance between the Sun and the Earth (called the Astronomical Unit); and the scale of the solar system could be subsequently determined by applying Kepler’s third law of planetary motion.

According to Iceinspace.com.au A Transit of Venus across the Sun occurs when the orbit of Venus takes it directly between the Earth and the Sun, obscuring a small portion of the Sun's disc. During the transit, Venus appears as a small black disc moving across the sun, usually taking several hours.
Transits of Venus across the Sun are extremely rare - one of the rarest of the predictable astronomical events, occurring in a repeating cycle of 243 years, with a pair of transits 8 years apart every 121.5 years and 105.5 years.

The last transit in the current cycle was in June 2004, but before that the last transit was in December 1874 and December 1882. The next transit after this one will be in December 2117 and December 2125 - so this is the last chance to see a transit of Venus in our lifetimes!

An even more rare occurrence is the Transits of Venus AND Mercury.  This has happened in the past with the last taking place on 22 September 373 173 BC.  If you are hoping to see that it will be on 26 July 69 163 (I doubt anyone of use will be around for that though.)

Amazingly, during one of the Transits of Venus, back in 1761 Russian scientist Mikhail Lomonosov made the discovery that Venus had an atmosphere. During the initial phase of the transit, he saw a ring of light around the trailing end of the planet (the portion that had not yet transited in front of the sun). He correctly inferred the only thing to explain the light refraction would be an atmosphere around the planet.

So, we understand that a great number of important discoveries about ourselves and our place in the universe have taken place as a result of the knowledge gained from the Transit of Venus, making it one of the most important celestial discoveries in our history, together with compositions of the moon etc.,

So for your interest and pleasure, I have put together a series of interesting facts about the Transit of Venus.

From Listverse.com –

First Transit of Venus “Movie”

Click on the image to follow the link
You do need a very fast link and Quicktime to view.

In December 1882, astronomer David Peck Todd traveled from Amherst College in Massachusetts to California to photograph the transit of Venus. The transits of 1874 and 1882 were the first since the invention of photography so Todd’s documentation of the Venus transit was one of the first made using photographs. On top of Mount Hamilton from what would become Lick Observatory (still under construction in 1882), Todd collected a series of photographs during the December 6 transit. Viewing conditions were ideal with no clouds and he collected 147 glass negative plates documenting most of the transit. The plates were carefully stored but soon forgotten as astronomers found better ways to view and document the transits. 

In 2002, two astronomers writing for Sky and Telescope magazine rediscovered the long forgotten plates, all of them intact and in good condition. They realized the sequence of photos could be made into the first “motion picture” of a Venus transit. The resulting “movie” documents one of the historic observations of a Venus transit. You can see the animation of the transit made using the 147 negatives here (warning – you need QuickTime and a fast internet connection). 

Did you know there was even a Transit of Venus March??  Yep.  There sure is – check this out!

Want to know and see more?

This link will take you to see a live feed of the Transit of Venus from Australia.  Check out this page for details – courtesy of NASA and Coca Cola (TM).  

To check out where to be in Australia and when – check out this timetable – courtesy of Transit of Venus website.  

Remember – A WORD OF CAUTION:  Never look directly at the Sun or you may cause serious and permanent damage to your eyesight. Damage can occur without any feeling that there is something wrong as there are no pain receptors in the retina and the damage may not become apparent for some time.

Courtesy of Wikipedia:

The safest way to watch a transit is to observe an image of the Sun projected onto a screen through a telescope, binoculars, pinhole or reflected pinhole. The event can be viewed without magnification using filters specifically designed for this purpose, such as an astronomical solar filter or eclipse viewing glasses coated with a vacuum-deposited layer of chromium. However, the disk of Venus is tiny compared to the sun and not much will be seen. The once-recommended method of using exposed black-and-white film as a filter is not now considered safe, as small imperfections or gaps in the film may permit harmful UV rays to pass through. 

So, why am I so excited to learn about the Transit of Venus? 

Well, any SciFi writer worth their salt would find this event fascinating, but I have a double reason to celebrate.  You see, STARFIRE, the second novel of the Warriors of the Elector Trilogy releases on the DAY of the Transit of Venus.  That doesn’t happen very often J as you will understand.

Happy Transit of Venus Day, everyone!

Imogene