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# Sizes of objects

4 replies to this topic

### #1 musicmatters

musicmatters

Sputnik

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Posted 12 May 2021 - 09:32 PM

of them are listed in degrees, which I think I understand.

But them some of them seem to be listed in feet.  (But I don’t think it actual feet)   Like the are listed as 30’ of 10’.  What does that actually mean?

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### #2 Deep13

Deep13

Aurora

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Posted 12 May 2021 - 09:39 PM

30' is thirty arc minutes. Sixty minutes to the degree and 60 seconds to the minute.

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### #3 Jon Isaacs

Jon Isaacs

ISS

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Posted 12 May 2021 - 09:51 PM

As Deep 13 said, 30" = 30 arcminutes, there are 60 arcminutes in a degree so 30' = 0.50°

30" = 30 arcseconds, there are 60 arcseconds in an arcminute so 30" = 30/ (60 x60) = 1 /120°

Jupiter is about 40" in diameter, the moon and sun about 30' or /.5°

Jon

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### #4 havasman

havasman

Voyager 1

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Posted 12 May 2021 - 10:20 PM

As Deep 13 said, 30" = 30 arcminutes, there are 60 arcminutes in a degree so 30' = 0.50°

30" = 30 arcseconds, there are 60 arcseconds in an arcminute so 30" = 30/ (60 x60) = 1 /120°

Jupiter is about 40" in diameter, the moon and sun about 30' or /.5°

Jon

Happens to us all Jon. I know you'd like to edit your post.

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### #5 BFaucett

BFaucett

Vanguard

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Posted 13 May 2021 - 12:37 AM

Minute and second of arc

https://en.wikipedia...d_second_of_arc

https://en.wikipedia...f_arc#Astronomy

Cheers! Bob F.

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