Transit of Venus, Not unmannedspaceflight but it's in space, so.... Options

[Explorer1]

Wow, just barely north of Iceland the sun will be half obscured in the middle by the horizon... I wonder if anyone will be there, around 66 N, 23 W? Should be amazing pictures, if the weather and icebergs won't interfere...

[ElkGroveDan]

Wow Toma, thanks for that.

And if you want to see the most amazing transit path, drag your locator pin out to the Pacific Ocean to a spot West of Hawaii, 21.6N, 167.8W

http://www.sunaeon.com/venustransit/

[mchan]

And close by at 22.7N 166.2W, Venus jumps across the disk within 2 minutes. The simulator plots on 1 minute intervals, so the trajectory is piecewise continuous here.

[Explorer1]

I can't understand the geometry of how this would happened, but no matter; if anyone manages to see/film that sort of motion it would be unreal. (are we sure that's not just a bug in the programming?)

[Hungry4info]

It has a lot to do with the rotation of Earth causing the orientation of the solar disc (and Venus on it) to rotate.

[nprev]

Wow Toma, thanks for that.

And if you want to see the most amazing transit path, drag your locator pin out to the Pacific Ocean to a spot West of Hawaii, 21.6N, 167.8W

http://www.sunaeon.com/venustransit/

THAT is ubercool!!!

[Explorer1]

I suppose its the same sort of effect as someone would see on Mercury, with the Sun stopping, going back a bit, and then shooting forward again.

Hope its not too late to charter a ship to go to one of these places?

[ElkGroveDan]

If you can't charter a boat, you could catch a flight to La Paz, Bolivia where there will be a similar looping transit path (though the show will be quite a bit better a few miles to the East or South of La Paz.)

[charborob]

Actually, the path of Venus across the Sun's disk is straight. This Website explains why the path appears curved or looped:
"The diagrams below to the clocks show the movement of Venus across the solar disk relative to the zenith, the point directly overhead. This is how you will see Venus advancing on the solar disk when observing with the naked eye or a telescope on an altazimuth mounting. Because of the diurnal motion of the celestial sphere, the sun’s disc rotates with respect to the direction of the zenith in the course of a day. The initially straight chord, representing Venus’ trajectory with respect to the north point, is now transformed into a curved path."

[Explorer1]

Oops, I think I broke it...

[attachment=26863:VenusTransit.jpg]

[TheAnt]

That path looks funny, so perhaps you managed to break it.

Now we're talking of Venus, the planet got a relatively young surface which have been flooded by lava over large areas.

Now research suggests that Venus might have been two planets that merged. And that might explain how Earth avoided getting frozen over back in the days when the Sun were a quite fainter star. Our world might have orbited closer to the sun, and moved outward later on trough interaction with one of the two proto-Venus planets. This is all somewhat speculative, so I think it belong in the Chit-chat section.

http://www.sciencedaily.com/releases/2012/...20530152034.htm

[jamescanvin]

I think the issue is the Sun./Venus goes almost directly through zenith so from the alt/az point of view, Venus is seen to rotate 180 degrees around the sun very quickly. The limited temporal sampling of the plot gives a few straight lines where is should be a near circle around the Sun.

[TheAnt]

@jamescanvin: I considered that for a moment myself, but the time for the transit is 15,09 to 21,28 with sunset at 20,48. I thought that black part of the graph is when the transit is not visible from that location. So its too late of the day for that - or am I missing something?

[ddeerrff]

A friend and I here at work were scratching our heads as to how those paths could be right - until we realized they were as viewed through an Alt-Az mount. Using an equatorial mount should result in a near straight line across the sun, correct?

[jamescanvin]

@jamescanvin: I considered that for a moment myself, but the time for the transit is 15,09 to 21,28 with sunset at 20,48. I thought that black part of the graph is when the transit is not visible from that location. So its too late of the day for that - or am I missing something?

Yes, but the crazy zig-zag bit is before the transit. The 'star' on the image is the position of Venus (off the disk) at the time shown in the upper right and is handily just before it executes the weird bit.

This is 13:52 local (-7 from GMT) however -134.7 longitude is very close to 9 hours behind GMT (9*15 = 135) so the sun will pass through zenith (the site is also very close to the tropic line near midsummer to ensure this) at roughly 14:00, just the right time.

@ddeerrff Correct