The two tourists were taken aback when they saw hundreds of purple mucus globes between the desert in America.
>>>Video: Mysterious spheres in the desert
Hundreds of viscous purple spheres expose the desert in Arizona, USA. (Photo: KGUN-9)
Geraldine Vargas - a woman in Tucson, Arizona, USA - with her husband riding a car in a desert for sightseeing last week, the AP reported.
"We are taking photos when we see purple balls. They are quite viscous and translucent," Geraldine said.
A group of reporters from KGUN-9 television channel came to the scene and filmed the balloons to broadcast.
Some people guess the spheres are a viscous substance. Another theory is that they are human-made products to absorb and retain moisture for plants. But these hypothetical supporters do not explain why the spheres appear in the desert.