Thanks, Daniel. -- Joe --- On Mon, 2/9/09, daniel turner <outwest112@yahoo.com> wrote: From: daniel turner <outwest112@yahoo.com> Subject: Re: [Utah-astronomy] quick question To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Monday, February 9, 2009, 2:48 PM Joe: On the entire sky there are 41,252.96127 square degrees. That's 148,510,660.6 square arc minutes. Or exactly 129600 x 3600 / PI. Or 4 x 180 x 180 x 60 x 60 / PI. These numbers derive from the fact that surface of a sphere is 4 times the area of a circle of the same radius and thus equal to 4 time PI in square radians and a square radian is (180/PI)squared degrees and a square degree is 60 squared square arc minutes. Of course the part of the sky above the horizon at any one time is only half that number. DT --- On Sun, 2/8/09, Joe Bauman <josephmbauman@yahoo.com> wrote:
From: Joe Bauman <josephmbauman@yahoo.com> Subject: Re: [Utah-astronomy] quick question To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, February 8, 2009, 9:47 PM Many thanks, Patrick. Does it make sense to multiply the two to arrive at the total number of square arc-minutes? Best wishes, Joe
--- On Sun, 2/8/09, Patrick Wiggins <paw@wirelessbeehive.com> wrote: From: Patrick Wiggins <paw@wirelessbeehive.com> Subject: Re: [Utah-astronomy] quick question To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, February 8, 2009, 10:41 PM
That would depend on which way you are measuring.
Going from the horizon (assuming a flat horizon) to the zenith and back down to the opposite horizon would be 180 degrees. Multiply times 60 (60 arc minutes per degree) = 10,800 arc minutes.
But measuring around the horizon is 360 degree or 21,600 arc minutes.
patrick
On 08 Feb 2009, at 22:29, Joe Bauman wrote:
Hi, Can anybody tell me right off-hand how many arc-minutes the night sky is? Thanks, Joe
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