Question Regarding Determining the Mass of Venus

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astropi
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TL;DR Summary
Trying to determine the "strange" units this paper is using.
Venus is in the news! I looked up this well-regarded paper by A. S. Konopliv, W. B. Banerdt, and W. L. Sjogren
Venus Gravity: 180th Degree and Order Model
They list values for GM (see attached picture), such as
GM 324858.63 ± 0.01
so in principle calculating M should be trivial. The problem is I am orders of magnitude off from the actual value. I thought perhaps they were using cgs units, but that gives a value for M that is 15 orders of magnitude off. Clearly, I'm missing something. I looked through the paper and couldn't find anything that clarified the situation. Anyone know the units they are using or what I am missing? Thanks in advance.

Edit: Just to clarify, this is NOT for homework or any school related activity. Simply my own understanding.
 

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  • #2
Bandersnatch
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Wikipedia said:
In celestial mechanics, the standard gravitational parameter μ of a celestial body is the product of the gravitational constant G and the mass M of the body.
\mu =GM\

For several objects in the Solar System, the value of μ is known to greater accuracy than either G or M.The SI units of the standard gravitational parameter are ##m^3 s^{−2}##. However, units of ##km^3 s^{−2}## are frequently used in the scientific literature and in spacecraft navigation.
That's your 9 orders of magnitude difference.
 
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astropi
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Thanks Bandersnatch, in retrospect that should have been pretty obvious!
 

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