Get ready for close encounters of the "curved" kind.
Former NASA astronaut Leland Melvin tweeted that he saw something "curved, organic looking" floating out of the payload bay during his time on the space shuttle Atlantis.
He told NASA about it, but the agency told him that what he was seeing was not an extraterrestrial but a piece of ice.
"I have not seen one in space or on the ground but thought I saw something organic/alien like floating out of the payload bay," Melvin tweeted, when asked by the Twitter account UFO Sightings Daily what his thoughts were on extraterrestrial life or if he had ever seen a UFO.
"@AstroKomrade and I called the ground to ask what it could be and it was ice that had broken off of the Freon hoses. Translucent, curved, organic looking👽"
Melvin, who played college football at University of Richmond and was drafted by the Detroit Lions in 1985 prior to becoming an astronaut, continued that he was going to say "Houston, we have a problem," but he did not want to be alarmist.
"I was about to say Houston we have a problem but know everyone spins-up when those words are uttered from a space vehicle. Godspeed🚀"
UFO Sightings Daily asked Melvin if he thought the government space agency was lying and responded by saying: "Hmmm. Don’t think so but you never know. 🚀"
It's unclear exactly what Melvin, who has degrees in both Chemistry and Materials Science Engineering, saw, but some on social media wanted to believe that Melvin's sighting was alien in nature, even if he may have been ribbing them.
"I think Leland is winding up alien fans, and as suggested it was probably an ice formation he saw," Ligel Watson, author of "UFOs of the First World War" told the Daily Mail. "Fortunately, he didn't test this explanation by going too close to it, otherwise it might have shot upwards to cling to his face and we all know what happens next."
NASA spokesperson Allard Beutel told Fox News that they "have yet to find signs of extraterrestrial life."
"NASA is exploring the solar system and beyond to help us answer fundamental questions, including whether we are alone in the universe. From studying water on Mars, probing promising 'oceans worlds,' such as Enceladus and Europa, to looking for biosignatures in the atmospheres of planets outside our solar system, NASA’s science missions are working together with a goal to find unmistakable signs of life beyond Earth."
The tweets come at a time when former government officials have suggested that humans may not be alone in the universe.
In 2015, Apollo 14 veteran Edgar Mitchell and the sixth man to walk on the Moon said he believed peacekeeping aliens visited Earth to prevent a nuclear war between Russia and the U.S.
Mitchell died in 2016 at the age of 85.
Luis Elizondo, a former Pentagon official who used to manage the Pentagon Advanced Aviation Threat Identification Program, also believes we may not be alone.
"My personal belief is that there is very compelling evidence that we may not be alone," Elizondo told CNN in an December 2017 interview.
Separately, reports from The New York Times and Politico in late December 2017 claimed the Defense Department secretly set up a program 10 years ago to investigate UFOs. Former Democratic Senate Majority Leader Harry Reid reportedly helped steer money under the program to a donor’s aerospace research company.
Fox News' Alex Pappas contributed to this story. Follow Chris Ciaccia on Twitter @Chris_Ciaccia