Which application to oprn ext. *.log.

I was e-mailed some files and asked to discover which application to use to open and view them. The files end in the extension *.log (i.e. moon5.log). The files are probably associated with an application used in general business or the gas and oil industry. I opened it in wordpad (too large for notepad) and could see some of the data, but it was too scrambled to manage. Any ideas