Green ball of light flying parallel to school bus.

I was traveling on a school bus on Highway 95 north, between Hawthorne and Fallon, Nevada, at around 10 p.m.  I looked out the window and saw a green glowing light flying level at the same speed as the bus.  I remember telling a couple of others sitting nearby, "hey, check out that light."  I don't remember their response.  
After watching a few minutes, I thought it must be some weird situation with the power lines along the highway, (though I don't know if power lines do run along that highway).  
I then slept.
Witness indicates that the date of the sighting is approximate.  PD