Nicole at Skepchick has links for how and when for this week in 2012. The Local Transit Times page on the Transit of Venus website reckons that for Sydney the details are as follows (and the Sydney Observatory reckons they’ve done their sums right):
Average Cloud Cover for June: 58%
ingress exterior Jun 6 08:16:09
ingress interior Jun 6 08:34:05
transit center Jun 6 11:30:12
egress interior Jun 6 14:26:23
egress exterior Jun 6 14:44:15
Notes on the data
Planetary transits start when the planet’s disk is externally tangent with the sun (ingress, exterior). From then, the planet may be discerned as a little black dent in the solar limb, gradually growing bigger until the entire planet is seen on the solar disk (ingress, interior). During the next five to six hours, the planet will traverse the sun’s disk until the planet’s disk will touch the opposite solar limb (egress, interior). The transit ends when the planet’s disk is externally tangent with the sun (egress, exterior).
For we Australians and New Zealanders, it’s one of those what-if history questions: if not for the 1769 transit of Venus where Captain James Cook was commissioned to take scientific observations from Tahiti, making for a neat stepping stone for an investigation of the Southern Oceans for evidence of the ‘postulated Terra Australis Incognita‘, how much longer might our islands have remained unknown to the Europeans? Which nation other than Britain might have discovered and settled us instead if Cook had been a less astonishing navigator/cartographer?
In Melbourne, Scienceworks is having a special breakfast, and the Observatory is doing observatory stuff from 9am. Hopefully there’ll be a little clear sky, but the forecast doesn’t look good!
Which nation other than Britain might have discovered and settled us instead if Cook had been a less astonishing navigator/cartographer?
Possibly the Dutch, or the French. Although they would have started off settling the west coast rather than the east. Given the western coast of Australia has been known of since approximately 1606 (Dirk Hartog landing on the island in Shark Bay that now bears his name), the main thing which stopped the Dutch from colonising here was simply that the population pressure hadn’t grown to a sufficient level to make exploiting what seemed to be a very bleak, unfriendly land (in European terms) even vaguely interesting. The main thing which drove the British colonisation of Australia was population pressure in the prison system, and the American colonies deciding on self-government (prior to 1776, convicts had been transported to the Americas as punishment – indirectly, this removal of one slave labour force was what drove a lot of the African slave trade as a result).
But yeah, if it hadn’t been the Brits, it probably would have been the Dutch or the French, since they were the other main colonial powers in the region. The Dutch were certainly aware of the western coast of Australia (Hartog in 1606 was followed by DeVlamingh in 1616, and there’s any number of Dutch ships which wrecked off the WA coast since then; the Batavia incident could well have been quoted as proof of colonists landing and surviving in the event of a disputed claim).
Hoping to catch the transit from the USyd quadrangle but the south-east weather looks very dicey for it. Tomorrow seems to have the worst forecasts though so perhaps Wednesday will play nice? Perhaps?
Fingers crossed, Mary!
well the skies are clearing after last night’s big storms, but there’s still many patches of fluffy white clouds up there – methinks transit-watching in Sydney is going to be a rather intermittent event today!
You think you can take me, clouds? Oh, it is on.
Very cloudy here in Perth. glad I didn’t travel halfway around the world in a tall ship.
Hope others are getting a better view.
Just got home from a sunshine and sea-breeze SAD-abatement outing – saw the big waves crashing below the cliffs at Coogee, then on the drive home saw some theodolites in a park with people looking upwards – went to check it out and they had sun-filters for the lenses, so I got to see the transit very clearly even though I had to stand on the lens-case to reach the eyepiece :)
Yay!
The most irritating aspect of the clouds was that it made it difficult for the physics students to set the telescopes (they wanted shadows to be cast to do the first-pass calibration): the sun would come out, they’d just get the telescopes pointing at the sun and BAM, cloud cover.
However, we got one decent break while I was there, so I saw it both by telescope and directly through solar viewing glasses from the USyd lawns in front of the quadrangle. I hadn’t actually understood that it would be easily visible with normal vision (in my case, with my normal glasses correction plus solar viewing glasses!) so that was a nice surprise.
Now, anyone going to try and see the November total eclipse from Cairns?
I was thinking of heading up to Cairns, but the prices for accommodation are, like the event itself, astronomical.
Melbourne had beautiful weather, and we had a great time at the observatory looking through the huge old telescopes. Got a little talk about their history too, which was pretty cool. I feel really privileged to have been there.
We had a wonderful day. Up absurdly early with our nuclear family plus my sister-in-law for a Captain Cook breakfast cruise affiliated with the Powerhouse Museum where we got to watch the ingress via weblink, then all charge up to the roof with our solar glasses whenever the sun peeped out, then back to the weblink when cloudy.
Then we’d vaguely planned to proceed to Macquarie Uni’s events, but I was starting to miss my sister – remembering travelling to Melbourne for a complete solar eclipse when I was small, I was very nostalgic for family. So I planned instead to proceed to Sydney Uni with our glasses so she could have a look on a tea or lunch break, and she filled me in on the events planned at the quad as Mary mentioned above, which clinched it. So late morning and afternoon were spent looking at telescopes and rubbing shoulders with fellow enthusiasts, then darting for cover from rain in the quad and showing the girls around it, then ducking back out when the sun peeped out.
I think we were there at different times, Mary. I hadn’t read the above and didn’t know to look for you, and I’ve only met you once. I *think* I’d at least have thought “I know that face”.
It was great fun writing my daughter’s note for absence from school – “obvious educational value in science and history”, “(for her) once in a lifetime …”. Still on a Transit of Venus buzz.