3I/ATLAS, the interstellar comet

About 3I/ATLAS

The full story, section by section

The story of 3I/ATLAS in 3 parts. Tap any part to read it in full.

1. Discovery and pathIts very high speed — about 58 km/s relative to the Sun before the Sun's pull sped it up — and its open, hyperbolic path showed it came from outside the Solar System and will not return.Read this part → Illustration drawn for this site — not a photograph.
2. What it is made ofTelescopes including Hubble and the James Webb Space Telescope saw a cloud of gas and dust (a coma) and a tail, with a lot of carbon dioxide.Read this part → Illustration drawn for this site — not a photograph.
3. The alien-technology debateLoeb wrote a series of articles listing features he considered anomalous, and argued that the possibility of an artificial object should be taken seriously.Read this part → Illustration drawn for this site — not a photograph.

Read the full 3I/ATLAS article →

Key people

The people at the centre of the story — witnesses, investigators, officials and sceptics:

• Avi LoebAbraham Avi Loeb is an Israeli-American theoretical physicist and professor at Harvard University who has researched astrophysics and cosmology. He became widely known for arguing that interstellar o…

Related cases & events

Events and sightings linked to 3I/ATLAS:

🗓️ Event · 2 min readʻOumuamuaThe first object known to have come from outside the Solar System, found in 2017 — and briefly suggested to be an alien probe.

Programs, organizations & documents

The official programs, groups and papers involved:

🏛️ Program or study · 2 min readSETIThe Search for Extraterrestrial Intelligence: listening for signals from civilisations on other worlds.

🗓️ 3I/ATLAS on the UAP timeline

1. Late 1963An Atlas missile launch officer's affidavit describes a glowing round UAP over his site in New Mexico. Read the article →
2. Late 1964An Atlas launch officer reports a UAP near his missile site in New Mexico. Read the article →

Search the timeline →

🏛️ Official records

• Mercury Atlas 7, May 24, 1962NASA · Released May 22, 2026During the fourth crewed spaceflight and second orbital flight of Project Mercury, Mercury-Atlas 7 (MA-7), Aurora 7 pilot Scott Carpenter describes white particles in view that appear to move at “random” and “look exact…
• Mercury Atlas 9 Audio Excerpt, May 15, 1963NASA · 1963-05-15During the final and longest flight of Project Mercury, Mercury-Atlas 9 mission (MA-9) Faith 7 Pilot L. Gordon Cooper Jr. describes the brilliant blue of sunrise beneath the haze layer of the Earth’s atmosphere. As he a…
• Mercury Atlas 9 Audio Excerpt, May 15, 1963NASA · 1963-05-15Approximately one hour and 41 minutes into the final and longest flight of Project Mercury, Mercury-Atlas 9 mission (MA-9) Faith 7 Pilot L. Gordon Cooper Jr. notes that he sees “John’s fireflies,” referring to John Glen…
• Mercury Atlas 8 Audio Excerpt, October 3, 1962NASA · 1962-10-03During the Mercury Atlas 8 mission, Sigma 7 pilot Walter M. “Wally” Schirra Jr. describes observing “little white objects that tend to come from the capsule itself and drift off.” Schirra later also refers to those obje…

🛸 UFO sightings about 3I/ATLAS

Sightings that mention 3I/ATLAS

Open the sightings map → Search sightings →

More in the encyclopedia

Other articles that link to or mention 3I/ATLAS:

• Wow! signalA strong radio signal recorded in 1977 that looked like what SETI was searching for, and was never heard again.
• Jerome Nelson's Atlas missile site sightingIn the early-to-mid 1960s at Atlas missile sites near Roswell, New Mexico, military personnel reported seeing silent, glowing unidentified objects hovering over silos and shining lights on guards. Ve…
• Philip Moore's Atlas missile site sightingIn late 1964, a neighbouring crew at the 579th Strategic Missile Squadron near Roswell, New Mexico, reported a UFO hovering over their Atlas missile site. Air Force personnel, including enlisted crew…
• UAP hearingsPublic hearings in the U.S. Congress on UFOs and UAP, from 1966 to the whistleblower hearings of 2023–2025.
• Richard BoylanRichard J. Boylan is an American psychologist and UFO writer who promotes claims of contact with extraterrestrial beings and secret government spacecraft retrieval programs. In 1997, he published an …
• EarthfilesEarthfiles is a website and YouTube channel run by American journalist and documentary maker Linda Moulton Howe. It reports on anomalies such as cattle mutilations, crop circles, and UFO crash-retrie…
• Galileo ProjectThe Galileo Project is a privately funded research project founded in July 2021 and led by Harvard astrophysicist Avi Loeb to search for physical evidence of extraterrestrial technology. By late 2025…

Questions & answers