[aprssig] [amsat-bb] Transit of Venus event 5/6 June

[Andrew P.]

Hope everyone else on the list has a clear day. The clouds are rolling in here in the Philadelphia, Pennsylvania, USA, area. Drat. Praying for a break by sunset, but I'm getting the telescope ready anyway.

Andrew KA2DDO


Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: Greg Dolkas <ko6th.greg at gmail.com>
Date: Tue, 5 Jun 2012 15:20:05 
To: <aprssig at tapr.org>
Subject: Re: [aprssig] [amsat-bb] Transit of Venus event 5/6 June

On Tue, Jun 5, 2012 at 2:11 AM, Bob Bruninga <bruninga at usna.edu <mailto:bruninga at usna.edu> > wrote:
 Re Transit of Venus:
 
 > Do I have my math right?  Your website says that
 > the transit starts around 05:13z, which is around
 > 10:13pm local time out here on the West Coast (UTC
 > -7).  How can that be, if according to the map, the
 > transit will still be in progress 5hrs later at
 > Sunset?
 
 I did a quick look at my site, and do not see the reference to 0513z.  Please let me know where the mistake is.
 
 I am in japan and cannot fix it anyway.  But I do know that it begins at about 6 PM EDT on the 5th of June on the east coast.
 
 GOod luck!
 Bob, WB4APR


It's at the end of the paragraph "Observing the Parallax" (colored emphasis is mine), right below the picture of the Camera Obscura:

Observing the Parallax: The Transit of Venus is a fascinating event historically as it gave early astronomers the first mechanism with which to actually measure the distance from the Earth to the Sun and confirm their underestanding of the size of Venus. During the 6 hour or so event, there are 4 critical times as shown below. These instances will occur at slightly different times for observers at different Earth locations because of parallax. But generally begin at 0513z and end at 1126z. 

Anyway, 5:13pm EDT (2:13pm PDT) works out a whole lot better.  Thanks!

Greg  KO6TH