While 31/ATLAS continues to fascinate scientists as an Interstellar comet discovered using the Atacama Large Millimeter Array, aka ALMA. In the meantime, the Earth experienced a separate—and startling—series of close encounters with much smaller space visitors.

Together, these events happen in the unpredictable cosmic neighborhood.

Interstellar Comet Takes Center Stage

Unlike nearby asteroids, 31/ATLAS originated around another star entirely. Observations from ALMA revealed that this interstellar comet contains unusually high levels of methanol and hydrogen cyanide—key molecules involved in the chemistry that leads to life.

“Molecules like hydrogen cyanide and methanol are at trace abundances in our own comets,” NASA astrochemist Martin Cordiner said. “In this alien comet, they’re very abundant.”

These discoveries are helping astronomers compare the chemistry of distant planetary systems with our own.

31/ATLAS A Near Miss No One Saw Coming

As scientists tracked 31/ATLAS, Earth had its own surprise. On Oct. 1, a small asteroid named 2025 TF passed just 266 miles above Antarctica—lower than the orbit of many satellites. Shockingly, it wasn’t discovered until hours after it had already flown by.

According to the European Space Agency (ESA), 2025 TF was only 3 to 6 feet wide, small enough to burn up if it entered Earth’s atmosphere, but close enough to raise eyebrows.

“It passed well within the altitude of the International Space Station,” ESA noted.

ESA’s planetary defense overview:
👉 https://www.esa.int

Another Flyby—This Time Detected in Advance

Less than a day later, astronomers at Mount Lemmon Observatory detected a second object, 2025 TQ2, before it arrived. This asteroid passed about 3,014 miles above Canada, closer than many geostationary satellites.

Though still harmless, such proximity is rare.

“These are classified as exceptionally close approaches,” EarthSky reported.

Read more at EarthSky:
👉 https://earthsky.org

A Busy Month for Planetary Defense

NASA’s Catalina Sky Survey and follow-up observations by Las Cumbres Observatory played key roles in tracking both objects. Amateur astronomer Tony Dunn also noted that 10 asteroids passed closer than the Moon between Sept. 23 and 28 alone.

“These were all discovered within the same month,” Dunn wrote on X.

Tony Dunn’s asteroid tracking post:
👉 https://x.com/tony873004/status/1973467071678914962

What It All Means

While the near-Earth asteroids were unrelated to 31/ATLAS, the timing highlights how interstellar comets and near-Earth objects need constant monitoring. One offers clues about alien chemistry, while the others remind us why planetary defense matters.

As Cordiner put it, “Interstellar objects give us a glimpse of how chemistry unfolds across the galaxy.”