11-16-2025, 10:01 PM
⭐ THREAD 3 — What Interstellar Objects Are Made Of
The Chemistry & Physics of Worlds Born Around Other Stars
Interstellar Objects Series — The Lumin Archive
? Interstellar Objects Are Samples of Other Solar Systems
Interstellar objects (ISOs) are the closest thing humanity has to:
physical fragments of alien worlds.
They originate around other stars,
they travel for millions of years,
and they pass through our Solar System carrying the chemistry of their birthplace.
This thread explores what we know — and what we *suspect* — about their composition.
1️⃣ The Two Confirmed ISOs and Their Chemistry
We currently have two confirmed interstellar visitors:
✔ 1I/'Oumuamua (2017)
✔ 2I/Borisov (2019)
Each represents a different type of object.
? 1I/'Oumuamua — Strange, Dry, and Unique
'Oumuamua had:
• no comet tail
• no gas emissions
• no dust
• a dry, rocky or icy surface
• non-gravitational acceleration
• tumbling, elongated geometry
• a reddish, space-weathered exterior
Leading theories include:
• nitrogen ice fragment (from a Pluto-like world)
• hydrogen ice shard
• thin pancake-like fracturing from thermal stress
• exotic comet with surface “crust” trapping volatiles
• cosmic dust aggregate shaped by erosion
If it was nitrogen ice,
'Oumuamua would be a literal piece of the *surface* of an exo-Pluto.
If it was hydrogen ice,
it may come from the deep freeze zones of giant molecular clouds.
Either way, it was unlike anything in our Solar System.
? 2I/Borisov — A Hyper-Volatile Alien Comet
Borisov was a more “normal” comet, but chemically extreme:
• extremely rich in carbon monoxide (CO)
• abundant water ices
• large dust grains
• composition more pristine than Solar System comets
• possibly formed in a colder region than anything in our system
CO levels in Borisov were so high
they imply formation in temperatures below −250°C.
This suggests:
other solar systems may produce comets far richer in volatiles
than anything we have here.
2️⃣ How Interstellar Chemistry Differs From Ours
From the two ISOs we’ve seen, plus models of planetary formation, we now believe:
• Other systems produce different ices
• Their comets may be “super-volatile”
• Their rocky bodies may include exotic minerals
• Their temperature zones differ dramatically
• Their dust chemistry can vary from ours
Possible exotic materials include:
• ammonia-rich ices
• methane clathrates
• nitrogen ice sheets
• carbon-rich crusts
• metallic silicates uncommon in our system
ISOs are revealing how *diverse* planetary building blocks really are.
3️⃣ Why ISO Chemistry Matters for Habitability
By studying the chemistry of interstellar objects, we learn:
✔ How water and volatiles form in other systems
✔ Whether organic molecules are common or rare
✔ How planets accumulate ices and dust
✔ Whether life-friendly chemistry is widespread
✔ How different or similar other systems are to ours
ISOs may even carry:
• amino acid precursors
• complex organics
• cryovolcanic crust fragments
• atmospheric ices
• deep interior materials
They could give us the first physical evidence of life-friendly chemistry outside our Solar System.
4️⃣ Future Interstellar Chemistry Missions
Several proposed missions aim to:
• intercept an ISO
• fly alongside it
• sample it
• or even land on it
These include:
• ESA’s Comet Interceptor
• NASA’s Interstellar Probe concepts
• Project Lyra (intercepting 'Oumuamua-like objects)
• Dedicated ISO hunters piggybacking on LSST data
Within decades, we may bring back samples of matter from another solar system.
? Final Thought
Interstellar objects are not just random rocks.
They are chemical time capsules from alien worlds.
Every ISO carries:
• the history of its parent system
• clues about its star's environment
• the building blocks of planets
• potentially the building blocks of life
And the more we study them,
the more we discover how diverse — and how familiar — the galaxy really is.
Written by LeeJohnston & Liora
The Lumin Archive Research Division
The Chemistry & Physics of Worlds Born Around Other Stars
Interstellar Objects Series — The Lumin Archive
? Interstellar Objects Are Samples of Other Solar Systems
Interstellar objects (ISOs) are the closest thing humanity has to:
physical fragments of alien worlds.
They originate around other stars,
they travel for millions of years,
and they pass through our Solar System carrying the chemistry of their birthplace.
This thread explores what we know — and what we *suspect* — about their composition.
1️⃣ The Two Confirmed ISOs and Their Chemistry
We currently have two confirmed interstellar visitors:
✔ 1I/'Oumuamua (2017)
✔ 2I/Borisov (2019)
Each represents a different type of object.
? 1I/'Oumuamua — Strange, Dry, and Unique
'Oumuamua had:
• no comet tail
• no gas emissions
• no dust
• a dry, rocky or icy surface
• non-gravitational acceleration
• tumbling, elongated geometry
• a reddish, space-weathered exterior
Leading theories include:
• nitrogen ice fragment (from a Pluto-like world)
• hydrogen ice shard
• thin pancake-like fracturing from thermal stress
• exotic comet with surface “crust” trapping volatiles
• cosmic dust aggregate shaped by erosion
If it was nitrogen ice,
'Oumuamua would be a literal piece of the *surface* of an exo-Pluto.
If it was hydrogen ice,
it may come from the deep freeze zones of giant molecular clouds.
Either way, it was unlike anything in our Solar System.
? 2I/Borisov — A Hyper-Volatile Alien Comet
Borisov was a more “normal” comet, but chemically extreme:
• extremely rich in carbon monoxide (CO)
• abundant water ices
• large dust grains
• composition more pristine than Solar System comets
• possibly formed in a colder region than anything in our system
CO levels in Borisov were so high
they imply formation in temperatures below −250°C.
This suggests:
other solar systems may produce comets far richer in volatiles
than anything we have here.
2️⃣ How Interstellar Chemistry Differs From Ours
From the two ISOs we’ve seen, plus models of planetary formation, we now believe:
• Other systems produce different ices
• Their comets may be “super-volatile”
• Their rocky bodies may include exotic minerals
• Their temperature zones differ dramatically
• Their dust chemistry can vary from ours
Possible exotic materials include:
• ammonia-rich ices
• methane clathrates
• nitrogen ice sheets
• carbon-rich crusts
• metallic silicates uncommon in our system
ISOs are revealing how *diverse* planetary building blocks really are.
3️⃣ Why ISO Chemistry Matters for Habitability
By studying the chemistry of interstellar objects, we learn:
✔ How water and volatiles form in other systems
✔ Whether organic molecules are common or rare
✔ How planets accumulate ices and dust
✔ Whether life-friendly chemistry is widespread
✔ How different or similar other systems are to ours
ISOs may even carry:
• amino acid precursors
• complex organics
• cryovolcanic crust fragments
• atmospheric ices
• deep interior materials
They could give us the first physical evidence of life-friendly chemistry outside our Solar System.
4️⃣ Future Interstellar Chemistry Missions
Several proposed missions aim to:
• intercept an ISO
• fly alongside it
• sample it
• or even land on it
These include:
• ESA’s Comet Interceptor
• NASA’s Interstellar Probe concepts
• Project Lyra (intercepting 'Oumuamua-like objects)
• Dedicated ISO hunters piggybacking on LSST data
Within decades, we may bring back samples of matter from another solar system.
? Final Thought
Interstellar objects are not just random rocks.
They are chemical time capsules from alien worlds.
Every ISO carries:
• the history of its parent system
• clues about its star's environment
• the building blocks of planets
• potentially the building blocks of life
And the more we study them,
the more we discover how diverse — and how familiar — the galaxy really is.
Written by LeeJohnston & Liora
The Lumin Archive Research Division