Observation Tech Finally Catches Up
Back in 2021, Siraj said, “We just don’t have the technology to see them yet.”
Four years later, the Vera C. Rubin Observatory has changed that.
Its Legacy Survey of Space and Time (LSST), which went live earlier this year in Chile, is already capable of spotting faint, fast-moving interstellar objects—predicting that the sky will now yield one detection every month.
This leap in capability means 3I/ATLAS is no isolated miracle. It could be the first in a parade of new discoveries revealing the galactic debris flow that constantly drifts through our solar system.
A Tale of Two Visitors
| Feature | Borisov (2019) | 3I/ATLAS (2025) |
| Speed | ~110,000 mph | ~130,000 mph |
| Size | Small comet nucleus (~1 km) | Significantly larger, multi-kilometer object |
| Composition | Icy, volatile, comet-like | Possibly metallic or silicate-based |
| Origin region | Cold outer disk of distant star system | Likely hot, inner disk ejection |
| Behavior near heat | Sublimated rapidly | Retained mass and shape |
Why It Matters
For planetary scientists, the contrast between these two visitors is the key to understanding how different solar systems evolve and die. If Borisov was the archetype of a frozen emissary from a stable, cold system, 3I/ATLAS may be evidence of a chaotic star system shedding its own planetary remains.
Each visitor is a time capsule. One froze. The other burned—and survived.
