What's the most well-used answer for questions we simply don't know the answer to? "Aliens." In all seriousness, encounters of the 4th kind are something that many people take very seriously. Furthermore, many people even claim to have had them or witnessed them. While it's enough to strike fear into the hearts of many who would rather not believe in other intelligent life forms, many are mystified and intrigued by these otherworldly encounters. We can't say for sure whether there's any definitive proof (we do not work for NASA or Area 51), of course...

These encounters seem to take place in the same locations around the country, and the US has had a surprisingly high number of reported extraterrestrial encounters over the last century or so. While unusual lights and eerie saucers are what make up our nightmares, many claim these things do exist... Do you believe them enough to track them down yourself?

10 Kenneth Arnold's Bizarre Sighting Near Mount Rainier, Washington

Washington is home to vampires and werewolves too (thanks, Twilight) so why not aliens, too? While flying his plane around Mount Ranier, Kenneth Arnold claimed to have seen nine glowing, blue aircraft flying in a "V" formation at roughly 1,700MPH back in 1947. It remains unexplained, but Roswell happened only weeks later.

9 Obviously, Roswell: New Mexico's Creepy Claim To Fame

Speaking of which, Roswell is still yet to be explained, however, New Mexico has made quite the profit off their local lore. While there was nothing actually found in the sky, it was reported that mysterious "debris" was left at the crash site. Unfortunately for UFO fans, the military admitted that the "debris" was actually a top-secret weather balloon. That doesn't mean other unusual activity has slowed, though.

8 Lubbock, Texas, Where Lights In The Sky Don't Mean Shooting Stars

For some reason, Texas as a whole seems to be a hotspot for these types of encounters. In 1951, only a few years after the previous incidents, the lights depicted in this photo were beginning to be seen in towns all over Texas. The only explanation is one that doesn't hold enough water to sound plausible, so it remains largely unexplained.

7 Levelland, Texas, Which Inspired The Movie Close Encounters Of The Third Kind

Raise your hand if you couldn't sleep for days after watching it! The scary part is that the electronic interference seen in the movie was based on real events: When strange lights appeared over Levelland, lights went out and car engines actually died. Thus, the birth of Project Blue Book, which tried to explain everything away via an "electrical storm."

6 Sightings Have Interfered With Malmstrom Air Force Base In Montana

Where there are mountains, there are UFOs... or something like that. These reports came from actual former Air Force officers, who made the claim that UFOs would hover over their nuclear missile silos. Supposedly, these hovering objects would render the missiles inoperable while they were within the base's airspace.

5 Even Phoenix Has Had Its Fair Share Of Unexplained Appearances

Phoenix is well-known for its UFO sightings, but there was an unusual phenomenon that occurred in 1997. This time, the story was backed by the city's former governor, Fife Symington, who is also a former Air Force officer. His account? "I witnessed a massive delta-shaped craft silently navigate over Squaw Peak, a mountain range in Phoenix, Arizona. It was truly breathtaking."

Related: Real-Life Ghost Ships: 10 Creepy Pics Of Sunken Wrecks From Around The World

4 Even Washington D.C. Has Seen Aliens Outrun Military Planes

The proof of this lies in the military's reaction to it: On multiple occasions, the Air Force was called on to deploy over the airspace of Washington D.C., due to unidentified aircraft. The headlines that followed would describe how the Air Force jets were outrun by these unexplained aircraft, which were only cruising between 100-130MPH before picking up speed and disappearing.

3 Delphos, Kansas, Where Physical Evidence Of The Extraterrestrial Was Found

This sighting, witnessed by Ronald Johnson, occurred at a farm that his family owned back in 1971. After witnessing a glowing object that was unfamiliar to him (backed up by one other account that night), he noticed that there was something left glowing on the ground underneath it. Soil collected by a scientist from the U.K. confirmed it held a chemiluminescent organic compound.

Related: Pilots Reveal: 10 Reasons They Refuse To Fly Over The Bermuda Triangle

2 Maine's Loring Air Force Base Has An Unexplained Incident Of Its Own

In 1975, two Air Force officers reported an object that they couldn't explain while on-duty at the base. As logs would later reflect, the cigar-shaped object they witnessed flying through the air would be explained with an odd description: "unidentified helicopter(s) flying out of Canada."

Related: The 10 Places In The World To Search For Aliens & UFOs

1 An Unexplained Presence Appeared In Someone's Car On The Highway In Marshall, Minnesota

This is perhaps one of the creepiest on the list simply because it's a bit too close for comfort. The sighting comes from Val Johnson, a former Sheriff's Deputy, one night while he was on-duty. When a ball of light appeared in front of him, the deputy drove toward it to investigate and next thing he knew, he woke up in a ditch with burns surrounding his eyes. The car also had damage, and Johnson claims the "ball of light" was in the car with him.

Next: 10 Travel Destinations Where People Have Claimed to Have Seen UFOs