While there are plenty of singular UFO sightings that have enough witnesses or striking details to make the newspaper healdines in local publications, the most compelling, and haunting, UFO sightings are the ones that happen en masse.

Dozens of witnesses may report seeing the same thing, all across a single area. Military personnel, civilians, amateur sky watching enthusiasts and everyone in between have all been recorded as seeing such “mass sightings” over the years.

Perhaps the most famous of these sightings occurred in Phoenix, Arizona 23 years ago during which thousands of people saw the same eerie cluster of lights in the sky. An explanation still hasn’t been released regarding this event, but those who saw it will never forget it, that much is for sure.

The Phoenix sightings are just the tip of the iceberg when it comes to UFO sightings, however.

Perhaps the most interesting of them all are clusters of sightings that have long been forgotten due to a lack of media attention, the remote location of these sightings, or any other number of factors.

Some of these sightings have even continued on a month-to-month, year-to-year and even generation-to-generation basis — and even despite that, a clear answer to what has been occurring has still not been found!

As far as unique mass sightings go, there are perhaps none more interesting than the infamous “Marfa Lights,’ or “ghost lights,” spotted in Texas that have mystified local UFO and paranormal enthusiasts for generations.

The Renowned Marfa Lights of Texas

Of all the UFO sightings I’ve witnessed in documentaries over the years, perhaps none stands out more than the Marfa Lights.

These Lights are a bit different from traditional UFO sightings but fascinating nonetheless. They typically appear as mysterious glowing orbs in the desert outside the West Texas town of Marfa, and are varyingly described as white, blue, yellow, red or other colors.

They are oftentimes reported to be the mere size of basketballs, but despite that, they continue to be seen clearly by local residents.

They also are known for dizzying maneuvers in the sky, incapable of traditional aircraft or even many of the UFOs that have been witnessed over the years. The Marfa Lights “hover, merge, twinkle, split into two, flicker, float up into the air or dart quickly” across Mitchell Flat (the area east of the town where they are most commonly reported, according to a report from Livescience.com).

While the lights are commonly seen, there seems to be no way to predict when these lights will come back, or if they even really exist at all.

Perhaps they are a sign of visitors from a parallel dimension?

One thing’s for sure…Something is going on, because the lights have been spotted for 135 years in the night’s sky, and they have made the town famous for UFO watchers across the country.

[An amazing interactive photo gallery of the lights from BBC News can be viewed here]

You can also check out a sighting video from one curious onlooker below:

Possible explanations for the Marfa Lights

Local academics have attempted to get to the bottom of the renowned Marfa Lights, but haven’t made much if any progress.

One theory is that they are a geological phenomenon caused by the local desert climate and energies trapped below the surface of the Earth that manifest themselves in the strange, eerily still looking orbs.

Under certain conditions, gases released by the Earth can become illuminated through natural phenomenon, causing the “orbs” to appear and glow.

Others think they could be caused by headlights from oncoming traffic in the distance.

Like any good “ghost story,” the details are being left for the observer to decide.

The theory that they are some type of alien craft that continues to visit and revisit is a constant and popular one as well, even though this theory lacks concrete evidence.

Needless to say, there is something strange about the lights, regardless of whether they are of extraterrestrial origin or not.

The location was even selected as one of the top 10 places to see a UFO in the United States according to David O’Leary, the creator of the Project Blue Book TV series based on the famous treasure trove of government UFO documents.

If you haven’t had a chance yet to make it to Texas to see these eerie lights, you are definitely missing out.

While some believe they are simple car lights, the long history of sightings seems to disprove that.

“These fireballs used to dance around my grandfather when he walking to and from school when he was young. He was born in 1910 and my mom was born therein 1938,” said one YouTube user.

There is also a book about the lights titled “Mysteries of the Marfa Lights” that can be viewed here.