Using Lightroom and .arw files

I don't know how this happened but somehow I managed to save a set of pictures to an .arw extension. How can I view and work with these photos? I really don't understand how this happened to a select few of my pictures. I really want to see and work with these images. Any help will be appreciated.

I figured it out....proprietary file extension for Sony. I used Lightroom to convert it back to a DNG file. All is good now.