Thetys is a Greek goddess, who was seen as the embodiment of water. She was the sister and wife of Oceanus and the mother of the world's rivers. She may seem a bizarre choice to lend her name to a place of punishing heat and arid dryness, such as this part of the Chihuahua desert. However, in antiquity, there was a sea here. It covered most of modern day Mexico and the USA; and its legacy is the millions of fossilized marine creatures, which litter the desert today.
To say that the area has some unusual phenomena is to understate the situation. There are more UFO sightings, strange lights, alien encounters, ghostly figures and spontaneously burning bushes in this isolated part of the desert, than there are in the entire rest of the country. There is also some unusual flora and fauna, including a purple cactus and a sub-species of desert turtle, which aren't found anywhere else on the planet.
Back in the 19th century, local farmers were telling visitors about the 'hot pebbles' that habitually fell upon the wilderness. Modern scientists are still seeing them, but they are calling them tiny meteorites or guijolas.
Studies of the soil have shown high levels of magnetite. As the name suggests, this is the most magnetic of all of the Earth's minerals. This might give you a clue as to what happens to iron in the area.
Amongst the stories is that of a ranch, close to the Zone of Silence, which is regularly visited by two blond man and a blonde woman. To all intents and purposes, they are human and they speak perfect Spanish. What makes them so strange is that they only ever ask for water and, when asked where they come from, they simply answer, 'from above'. They are also wearing raincoats, which isn't common attire in a blazing hot desert.
The family on the ranch aren't alone in meeting them. A scientific researcher became separated from his party and was lost in the Zone. He was just starting to panic, when he spotted three blond haired people, wearing 'raincoats and ball caps'. They directed him back to civilization.
This is similiar to the experience of Josefina and Ernesto Diaz, a couple of fossil hunters, who got stuck after a rainstorm induced flash flood. This was on October 13, 1975, when their truck ended up in a hole, from which they could not simply drive out. As they surveyed the problem, they were approached by tall, blond men, in yellow raincoats, who suggested that the couple get back into their vehicle.
They did so and felt the truck being lifted and pushed back onto solid ground. Thankful and thrilled, the couple left their truck to shake the hands of the men. But they were now alone. The desert stretched for miles in each direction without a sign of their assistants. There were no footprints in the sodden sand.
A TV reporter also spotted them. Luis Ramirez Reyes was travelling with a photographer, in November 1978, with a view to investigating the area for a possible feature in a programme. As the two drove along, he saw three blond men, with raincoats, at the side of the road, watching them. The photographer was driving and, to the reporter's surprise, didn't stop the car.
As Reyes pressed him for a reason why, the photographer replied with incredulity that he hadn't seen then. This alone was enough to spook Reyes, but as they continued driving into a totally different part of the desert, he saw the same three men again, standing watching. As before, the photographer couldn't see them.
Travellers through the area often encounter the ghostly figure of a blond man, who just drifts across the road or is glimpsed walking across the landscape.
However, none of this is explaining why it's called the Zone of Silence. This is because no communication devise works there. Radio waves are randomly deadened. Cellphones have no signal; walkie-talkies just transmit white noise; televisions and transistors receive nothing but static; even compasses can't find north, but spin around on the spot.
This would be a harmless curiosity, but for the fact that it also destroys the equipment of anything flying above it. In fact, publicity for this place first leaked out after a pilot, Francisco Sarabia, crash-landed in the zone during the 1930s. He claimed that his 'plane's radio had stopped working, as he flew across.
Even more dramatic was what happened in 1970, when a US Athena missile left Utah bound on a test flight to New Mexico. However, the missile overshot its landing spot. NASA observers reported that it was as if the missile was suddenly pulled off course. It continued into Mexico and crashed into pieces in the Zone of Silence.
With the permission of the Mexican government, a team of US scientists and military crossed the border to the crash site. They discovered that not even satellite signals worked there. Short waves, radio waves, television waves, you name it, it was silenced.
These are just a few of the strange stories attached to the Zone of Silence. Many theories have been proffered to explain the strangeness of the area. They range from the spectacular to the prosaic, but none have definitely solved the mystery.