🚨 BREAKING: The Hubble Space Telescope has officially captured 3I/ATLAS only the third interstellar object ever discovered.
It’s an active, icy body ejecting material, and possibly the most important visitor from beyond our solar system yet. 🧵👇
It’s an active, icy body ejecting material, and possibly the most important visitor from beyond our solar system yet. 🧵👇
2/
On July 21, 2025, Hubble locked on to 3I/ATLAS and confirmed what many suspected:
It's really fast (58 km/s), it’s interstellar (eccentricity > 6)
and it’s active, leaking ice into space.
We’re not just watching it, we’re interacting with it.
On July 21, 2025, Hubble locked on to 3I/ATLAS and confirmed what many suspected:
It's really fast (58 km/s), it’s interstellar (eccentricity > 6)
and it’s active, leaking ice into space.
We’re not just watching it, we’re interacting with it.
3/
This makes 3I/ATLAS only the third confirmed interstellar object ever observed after ‘Oumuamua (2017) and 2I/Borisov (2019).
But this one we’re catching it in far greater detail.
With ground + space telescopes, spectroscopy and trajectory modeling.
This makes 3I/ATLAS only the third confirmed interstellar object ever observed after ‘Oumuamua (2017) and 2I/Borisov (2019).
But this one we’re catching it in far greater detail.
With ground + space telescopes, spectroscopy and trajectory modeling.
4/
Hubble’s imagery shows a fuzzy, comet like coma, a sign of outgassing.
But the real revelation came from Gemini South and NASA’s Infrared Telescope Facility.
Their combined spectroscopic analysis (published July 22) confirms: water ice is present in the coma.
Hubble’s imagery shows a fuzzy, comet like coma, a sign of outgassing.
But the real revelation came from Gemini South and NASA’s Infrared Telescope Facility.
Their combined spectroscopic analysis (published July 22) confirms: water ice is present in the coma.
5/
Using near-infrared spectra and radiative modeling, researchers found that the coma is composed of:
30% large water ice grains.
70% Tagish Lake like dust (D-type asteroid analog)
The ice signal is real and visible in the 2.0 μm absorption band.
Using near-infrared spectra and radiative modeling, researchers found that the coma is composed of:
30% large water ice grains.
70% Tagish Lake like dust (D-type asteroid analog)
The ice signal is real and visible in the 2.0 μm absorption band.
6/
This tells us 3I/ATLAS likely formed beyond the snowline in its home star system, the same cold, icy frontier where our own comets are born.
It’s a chunk of someone else’s protoplanetary disk, wandering into ours.
This tells us 3I/ATLAS likely formed beyond the snowline in its home star system, the same cold, icy frontier where our own comets are born.
It’s a chunk of someone else’s protoplanetary disk, wandering into ours.
7/
Unlike 1I/Oumuamua (no coma, tumbling), and unlike 2I/Borisov (no ice confirmation), 3I/ATLAS is now the best characterized ISO ever.
Sublimating, reacting and showing us its chemistry and its history.
Unlike 1I/Oumuamua (no coma, tumbling), and unlike 2I/Borisov (no ice confirmation), 3I/ATLAS is now the best characterized ISO ever.
Sublimating, reacting and showing us its chemistry and its history.
8/
Its reflectance matches D-type asteroids, not ultrared KBOs like Quaoar.
That means it’s dusty, but not ancient and inert.
The slope flattening beyond 1.5 μm strongly supports active water-ice release, not just surface reflection.
Its reflectance matches D-type asteroids, not ultrared KBOs like Quaoar.
That means it’s dusty, but not ancient and inert.
The slope flattening beyond 1.5 μm strongly supports active water-ice release, not just surface reflection.
9/
No CN gas (yet), but don’t worry, it’s still far from the Sun. Most comets don’t release cyanide until they’re inside 3 AU. 3I is still 4 AU away.
We may see CO or CO₂ driven activity emerge next as it nears perihelion in late October.
No CN gas (yet), but don’t worry, it’s still far from the Sun. Most comets don’t release cyanide until they’re inside 3 AU. 3I is still 4 AU away.
We may see CO or CO₂ driven activity emerge next as it nears perihelion in late October.
10/
Its approach:
Closest to Mars: early October
Closest to Sun (perihelion): Oct 29 (~1.36 AU)
Closest to Earth: Dec 19 (~1.8 AU)
Best visible: late 2025 (with telescope)
It won’t hit us, but it will leave a visible chemical trail we can read.
Its approach:
Closest to Mars: early October
Closest to Sun (perihelion): Oct 29 (~1.36 AU)
Closest to Earth: Dec 19 (~1.8 AU)
Best visible: late 2025 (with telescope)
It won’t hit us, but it will leave a visible chemical trail we can read.
11/
This Hubble photo is so much more than a picture.
It confirms that life giving water exists far beyond our solar system, carried by comets across light-years, just like our own icy messengers.
3I/ATLAS is a fragment of some alien nursery.
This Hubble photo is so much more than a picture.
It confirms that life giving water exists far beyond our solar system, carried by comets across light-years, just like our own icy messengers.
3I/ATLAS is a fragment of some alien nursery.
12/
When you look at that Hubble image, you’re not just seeing a comet.
You’re looking at the frozen memory of another star’s formation.
3I/ATLAS has traveled billions of years to be seen by human eyes and it’s leaving a trail of water behind as it says hello.
Source:
NASA Hubble: July 2025 mast.stsci.edu/search/ui/#/hs…
Yang et al. (2025) arXiv: arxiv.org/pdf/2507.14916
#3IATLAS #Hubble #JWST #Interstellar #Astronomy
When you look at that Hubble image, you’re not just seeing a comet.
You’re looking at the frozen memory of another star’s formation.
3I/ATLAS has traveled billions of years to be seen by human eyes and it’s leaving a trail of water behind as it says hello.
Source:
NASA Hubble: July 2025 mast.stsci.edu/search/ui/#/hs…
Yang et al. (2025) arXiv: arxiv.org/pdf/2507.14916
#3IATLAS #Hubble #JWST #Interstellar #Astronomy
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