Venus transit: ingress and deepest

Event Date: June 5th
Time: 3:07/6:27 PM*

Brief

   Today's journal will be the most special that I ever do: the transit of Venus!  The date and time above represents when it is seen from our location at (rounded) 38º N, 122º W.  For this event, there is not too much need to be as precise as I normally am with coordinates; the data I retrieve from websites will have cities listed as opposed to exact locations.  Fortunately however, the Starry Night software lets a person view the transit from any coordinate point on Earth *where it is visible.  Therefore, the hundreds (or thousands?) viewing from Chabot Space and Science Center including me, will see the times for ingress and deepest transit.
   There is one other reason that this journal is special as a result of featuring the Venus transit: it will be the only one that I ever view (safely!) during my lifetime; the next one does not happen for another 105 1/2 years.

Detailed

First before magnifying silhouette-Venus and the Sun, I will show a zoomed out image for when the transit's ingress begins:

The first thing that you may notice is that for Venus' orbit, we are looking directly edge-on towards the plane of it.  Naturally, this has to be the case, as Venus is also near its descending node (with the ecliptic).  Just as I have mentioned several times with the Moon's orbit and nodes, Venus' transit of the Sun is similar to the concept as a total eclipse of the Sun: it happens when we see Venus' disc completely dark, facing away from the Sun, the way that the Moon must be in "new" phase for a solar eclipse.  Unlike the Moon however, there is no "precession of nodes" for Venus or the other planets.  Therefore, the only times that a Venus transit is possible is during the months of June and December.  Since for so many other years we see Venus at a phase other than "new" during these months, that is what makes the transits as rare as they are.  From Sky and Telescope's link here, http://www.skyandtelescope.com/observing/highlights/Transit-of-Venus-February-2012-134332798.html I include the following:

<<a transit of Venus, happens only four times every 243 years. However, the spacing between each occurrence is very uneven: it's 121½ years, then 8 years, then 105½ years, then 8 years again. The last transit occurred in June 2004 — and after this June's event there won't be another until December 2117.>>

The second image is a zoom-in, this time featuring the deepest transit, and the field of view is 1/4º.  Notice that Venus--just slightly less than 1 arc-minute in angular size--has a disc size that is big enough to see the planet's (current) dark-side easily across the Sun.  I darkened the image to night-mode to make both the Sun and Venus more visible.  Remember that a transit is the only way to see Venus during inferior conjunction; for any other time, it is just passing east or west of the Sun, in blinding glare.  Once again, remember to use a recommended safety filter when viewing the transit!

   *NOTE: most websites that you many come across will show eastern or universal time for the beginning, middle and end of the transit.  Translate accordingly to your own, if you are somewhere else in the world where it is visible.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.