We’ve now had three known interstellar objects pass through our solar system:

ʻOumuamua (2017) 2I/Borisov (2019) And now 3I/ATLAS, discovered in 2023.

Unlike Borisov (clearly a natural comet), and unlike ʻOumuamua (which behaved oddly but didn’t outgas like a typical comet), 3I/ATLAS is raising eyebrows again. Its trajectory, shape, and reflectivity are weird enough that some researchers are revisiting the same questions we asked in 2017:

What if it’s not just a comet? Not saying it’s aliens—but also not not saying it.

A few interesting notes:

It has an unusual light curve that doesn’t match standard comet behavior.

Some models suggest its motion can’t be explained just by gravity and solar radiation pressure.

It’s fast, small, and left no clear debris trail.

We still don’t know what these interstellar visitors really are. Are they relics of planetary systems? Failed probes? Natural objects shaped by unfamiliar processes?

Either way, I love that these things are flying through the neighborhood and leaving us scratching our heads.

What do you think 3I/ATLAS is? And what would it take for the scientific community to take the “non-natural” hypothesis seriously?