[meteorite-list] Fw: term definitions and usage

[Chris Peterson]

Ga is billions (gigayear) of years. Ma is millions (megayear) of years. 
"a" is the most commonly used symbol for year (from annus) in scientific 
publications.

Chris

*******************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On 7/24/2011 7:26 PM, Richard Montgomery wrote:
>
> Hello List,
>
> Another neophyte question (I can use some clarification): when / how are
> the time-measurements (relatively speaking) designations "Ga" and Ma"
> used, and their respective differences?
>
> (I believe I know the difference through context, but why go through so
> many papers and texts with the question-mark over my head?)
>
> Sincerely,
> Richard Montgomery