Cars stopped along Highway 21, with numerous people filming the mysterious shape flying in the distance.
Take a drive through Alien Country where there are more UFO sightings than at any other place on the planet.
Despite the secrecy and rumors surrounding this top-secret U.S. military facility in the Nevada desert, here are some things we do know about Area 51.
Scientists at Johns Hopkins University assessed the experiences of over 2,000 people who had taken the psychedelic drug.
"There is a reasonable chance that the planet hosts a large ocean underneath the atmosphere at pressures and temperatures similar to those in the Earth's oceans," researcher Nikku Madhusudhan said.
Dr Helen Sharman has publicly announced that she believes extraterrestrial life exists — and aliens might be among us on Earth right now.
"'Are we alone?' is one of the biggest unanswered questions," said study first author Howard Chen.
"We're all here today, so I don't think Independence Day happened yesterday evening," WFAA meteorologist Kyle Roberts told his viewers while explaining the crop circles on the weather radar.
Human's evolved through a series of highly unlikely events—so finding another intelligence like us would be like winning the lottery many times over.
"I can't believe we are the only living entity in the universe," Didier Queloz said
Data from the Cassini mission have revealed molecules in ice grains emanating from the icy, water-rich world.
It seems many Twitter users can't believe anyone actually showed up.
Area 51 has long been a target for conspiracy theories.
"Dear #Area51 raiders, 1. This is a terrible idea. 2. Make sure you spend all your money on fries before you go. 3. Zig-zag," one user wrote.
Cattle have been mutilated with precision-like surgery, with tongues and genitals removed, and not a trace of blood or any tracks that lead to clues.
Most Americans believe the governent is hiding something about UFOs, with the belief in extraterrestrial spaceships held by a substantial minority.
"In the search for life beyond our solar system, the most promising planets might not be Earth twins," says geochemist Stephanie Olson.
Warmer conditions on Ancient Mars increase the possibility that life developed there, according to researchers.
The sweepstakes winners will be announced on Friday.
The tongue-in-cheek gathering was inspired by the "Storm Area 51, They Can't Stop All of Us" event.
Tear gas and pepper spray readied against anime fans outrunning bullets at Area 51.
More than 4,000 planets beyond our solar system have been discovered since the first in 1992.
Scientists will use FAST to look for magnetic fields on exoplanets—a sign life could exist there.
The joke Facebook event urges attendees to run "Naruto style" at Area 51 to "move faster than their bullets" and "see them aliens." Will anyone show up?
Do you care about the search for extraterrestrial intelligence? Let these researchers know.
Breakthrough Listen is a program designed to search for evidence of alien life by scouring the the skies for distant radio signals.
The ocean is thought to be be billions of years old and may contain as much as three times the volume of all the liquid water on Earth.
Build-ups of toxic gases in the atmospheres of many exoplanets in the "habitable zone" could limit the "safe zone" in which life outside our solar system could actually exist.
NASA's James Webb Telescope will open up an entirely new avenue for searching for extraterrestrial life.