How many astronauts have reported an alien encounter of some kind?

Question

This question will be controversial, so I want to start out by saying that I am not advocating any sort of conspiracy. I'm merely acknolwedging the fact that there are numerous claims that some astronauts have said they have seen UFOs or some other sign of extraterrestrial intelligence (ETI). Some of these claims are dubious, whereas others seem to have some substance.

There are five types of purported encounters:

• UFO sightings
• Extraterrestrial artifacts
• ETI sightings
• Abductions
• Contact

Please be specific about what type of encounter happened.

A good answer should:

• list astronaut/s by name,
• detail what occured in the encounter, and
• provide strong evidence for the account.

Many "documentaries" and websites have quote mined things that various astronauts have said, so be careful to bring the full context to bear.

(I would like to count all who have been to space, regardless of nationality or whether or not they were pilots, etc. But please provide detail on each astronaut's nationality and qualifications.)

Answer 1

_{This is a community wiki. Please contribute any additional information you find. The following list is likely incomplete, so the total number of astronauts that follows is subject to change.}

There are four astronauts that have reported an encounter of the kind detailed in the question.

In alphabetical order (by last name, then first name) they are:

• Gordon Cooper - a NASA astronaut and one of the original seven astronauts on Project Mercury

  • First Encounter - UFO sighting in the early 1950s, before his days as an astronaut

    According to a Space.com article:

    "On one occasion, I saw some strange vehicles that we assumed were UFOs," he told Bell.

    In the encounter, which took place over Germany in the early 1950s, Cooper saw "flights of fighters flying by in the same sort of formation we flew, moving east to west." The U.S. Air Force base scrambled its own pilots, including Cooper, who remembers the objects as looking "just like saucers -- they were metallic looking, but we couldn't really get close enough to see more than that. You couldn't see any wings on them."

  • Second Encounter - UFO sighting in 1957, also before his days as an astronaut

    From the same Space.com article:

    He also stood by his belief that he saw a UFO land at Edwards Air Force Base in California in 1957. Although Cooper had been filming the base with a camera crew at the time, the film, which he handed over to a high-ranking officer from Washington, has never emerged.

• Pavel Popovich - a Soviet cosmonaut, commander of Vostok 4 and Soyuz 14

  • Sole Encounter - UFO sighting at an unspecified time

    Popovich was a UFO researcher for the Soviet government, and it is likely this account occurred during or after his work as a UFO researcher. The primary source for the account is the UFO documentary Out of the Blue, and it is possible that his account may be misconstrued due to bias. However, without any record of Popovich contesting the presentation of his account in this documentary, this answer will tentatively assume it was accurately reported. Here are the English subtitles of his account in Out of the Blue:

    For some reason, I was compelled to look out the plane's window. I looked and my eyes grew real big. I saw next to us, about one and a half kilometers away, and about 1,000 meters higher, there is a flying object. Its shape is a perfect right triangle. It was white, white, a very bright white. I'm a pilot, a fighter pilot, and I know many different types of flying crafts. It was like nothing I've ever seen.

    The Out of the Blue narrator explains:

    [He was] flying home from Washington, D.C. with a delegation of scientists.

    Pilots contacted ground control. Ground control did not detect anything on radar, even though the object could be seen by all occupants of the plane.

    Popovich continues (English subtitles):

    It travelled a parallel course. And its speed -- if we were travelling approximately 950 to 1,000 kph, it was travelling at about 1,500 kph, because it passed us rather quickly. In about 30 or 40 seconds it passed by, and overtook us. And that's all. And no academic, or anybody, could say what that object was.

• Donald "Deke" Slayton - a NASA astronaut and one of the Mercury Seven

  • Sole Encounter - UFO sighting in 1951, before his days as an astronaut

    According to his autobiography Deke!:

    It was when I was doing a maintenance test flight like this that I had my one and only encounter with an unidentified flying object.

    I was up about the middle of one afternoon--a nice sunny day--wringing out this particular 51. I had just come out of a spin at around ten thousand feet over the Mississippi River, near Prescott, where the Mississippi and the St. Croix meet, about twenty-five miles from the Twin Cities. I was heading back to Holman Field when all of a sudden I saw this white object about my altitude, at one o'clock.

    I didn't think anything about it. My first thought was that it looked like a kite. But logic said nobody's flying a kite at this altitude. So I started kind of watching to see what it was.

    I was closing on it, but I still didn't think too much about it. The closer I got, the more it looked like a weather balloon, and I'm thinking, that's what it's gotta be. Then I flew past it a little high, about a thousand feet off. It still looked like a three-foot-diameter weather balloon to me.

    My guess on the dimensions couldn't have been too far off. I had plenty of gas, so I figured I'd make a pass on it. Burn some gas and have a little fun. I pulled into a turn.

    But when I came out of that turn and headed straight at it, all of a sudden it didn't look like a balloon anymore. It looked like a disk on edge! I thought, that's strange. Then I realized I wasn't closing on that son of a bitch. A P-51 at that time would cruise at 280 miles an hour. But this thing just kept going and climbing at the same time at about a forty-five degree climb. I kept trying to follow it, but he just left me behind and flat disappeared.

    I wondered what that was, but I never saw it again. I turned around, headed back, and landed, and didn't tell anybody about it for two days. I was afraid they'd think I'd lost my mind.

    A couple of evenings later I was over in the O-club with my boss, a full colonel, and after I [sic] couple of beers I thought I'd better tell him, and I did. He said, "Get your ass over to Intelligence in the morning and give them a briefing." So I did. They sat there and nodded and took notes.

    Then they told me: Just for your information, the day you saw this object a local company was flying high-altitude research balloons. They had a light airplane tracking it, and a station wagon on the ground. Both observers were watching this balloon and had seen this object come up beside the balloon. The object appeared to hover, then it took off like hell.

    The guys on the ground tracked it with a theodolite, and they'd computed the speed at four thousand miles an hour.

• Robert White - a US Air Force astronaut who acheived suborbital spaceflight by X-15 on 17 July 1962

  • Sole Encounter - UFO sighting in 1962

    From the book Beyond Belief:

    [T]est pilot Robert White is reported as exclaiming in flight 'There are things out there. There absolutely is'. This certainly sounds impressive. However, Good omits to describe what White was talking about. So I had to go to the reference (Time magazine, 27 July 1962). This revealed that White was talking about an object looking 'like a piece of paper the size of my hand'. This is hardly strong evidence for UFOs...

---

A previous version of this answer included this alleged encounter:

• Frank Borman - a NASA astronaut and commander of Gemini 7 and Apollo 8 missions

  • Sole Encounter - UFO sighting in December 1965, in orbit during Gemini 7 mission

    From the Gemini 7 mission transcript (C and CC replaced with Borman and Capcom, respectively):

    Borman: Gemini VII here. Houston, how do you read?

    Capcom: Loud and clear, VII. Go ahead.

    Borman: I have a bogey at 10:00 o'clock high.

    Capcom: This is Houston. Say again, VII.

    Borman: Said we have a bogey at 10:00 o'clock high.

    Capcom: Roger.

    Capcom: Gemini VII, is that the booster or is that an actual sighting?

    Borman: ...

    Capcom: Say again, VII.

    Borman: Said ... we have several - looks like ... actual sighting.

    Capcom: Do you have any more information, estimated distance, or size?

    Borman: We also have the booster in sight.

    Capcom: Understand you also have the booster in sight. Roger.

    Borman: ... there are very many - looks like hundred of little particles going by from the left out about 3 or 4 miles.

    Capcom: Understand you have many small particles going by on the left. At what distance?

    Borman: ... looks like ...

    Capcom: Roger. Understand they're about 3 or 4 miles away?

    Borman: They're past now; they're in a polar orbit.

    Capcom: Roger. And understand they were about 3 to 4 miles away?

    Borman: That's what it appeared like, or further.

    Capcom: Roger.

    Capcom: Gemini VII, Houston. Were these particles in addition to the booster and the bogey at 10:00 o'clock high?

    Borman: ...

    Capcom: Roger.

    Borman: Houston, this is VII.

    Capcom: Go ahead.

    Borman: I have the booster on my side and the brilliant body of the sun against a black background with billions of particles around it.

    Capcom: Roger. What direction is it from you?

    Borman: It's about 2:00 o'clock position.

    Capcom: Does that mean it's ahead of you?

    Borman: It's - ahead of us at 2:00 o'clock and it's slowly tumbling.

    Capcom: Roger.

    Note: It is unclear whether Borman confirmed that the bogey was a separate entity from the particles.

However, Borman later explained in a 1999 interview that he was referring to the second stage.