A crop circle appears in a field after UFO sighting

On Monday 30th December 2013, two friends, that driving on Chualar Canyon Road (in the South of Salinas, California), have noticed strange bursts of green light flashing on the horizon. Intrigued, passenger has filmed this strange phenomenon.

They left the car, and they hopped a barbed-wire fence to walk toward the lights. The two friends have investigated this field in a Chualar farm. They then found a complex and fascinating crop circle.

Witnesses’ state on Youtube:

A friend and I were driving on Chualar Canyon Road south of Salinas, California before sunrise, and THIS happened. Needless to say, pretty wild, but we slipped away and it's too good not to share. Created this account since I don't want this tied to me. Still not sure what to make of it.

The next morning, a professional photographer, Julie Belanger, has also discovered this crop circle when she flew in a helicopter over the farm by coincidence:

It was beautiful. Quite beautiful. I believe it's possible that aliens exist, but I don't know if they would bother making a crop circle to give us a message.

What is it? A new hoax? Or an alien message?