square green flourscent light projecting a control beam of light by speed and depth from the sky to ground

at 20:00 on a nevada dirt road we saw a flourscent green square light, 75 feet in the air, and 75 feet off the road, about 45 degrees from our vehicle. the light was green like a glow stick for emergency light, about 2' x 3' perfectly square. we stopped to see what it was, the square light began to control a beam of green light towards the ground, still keeping the perfect square shape! the beam slowly extended downwards at a very slow rate, inside of the square beam it looked like smoke or dust swirling around inside! the green square 2' x 3' beam came down to within 2 feet over the top of a sage brush bush and stopped, the sage brush bush was illuminated the purest white color i have ever seen. how can the bush be white, when the beam was green, what can control the speed, and depth of light? i got out to see if i could hear any motor noise, i was only 75 feet away, and there was zero noise!!! i could not make out any type of craft, only a square green box light that was producing a square green beam? we were freaked out and left driving into the heavy timber about a mile down the dirt road, even our 2 dogs were acting strange, almost cowarding down? about 45 minutes later when we calmed our nerves, we drove back to the spot, there was'nt anything there except for a flourscent green aura or cloudy area where the beam had been. i know this area better than the back of my hand, i have hung out there for many years, this was something not from this planet!!! i would like to talk to someone about it, i studied the scene for sometime during the sighting, this was 20+ years ago, and i still remember it like i was still there!!! i can be reached at home in the evenings at 775- ((telephone number and name deleted)), reno, nevada.