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That small dot moving left to right is 3I/ATLAS. It's a comet that was discovered on 1 July 2025. It's travelling at 58 km PER SECOND and isn't gravitationally bound to the Sun. Which means you're looking at a comet that formed around another star, passing through the Solar System.

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3I/ATLAS was discovered with the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) survey telescope in Chile. Its nucleus size is uncertain because of the comet's coma, but is likely substantially smaller than 24 km in diameter.

This video sequence was posted on 2 July 2025 by astrafoxen ‪(astrafoxen.bsky.social‬), and spans 41 minutes. The comet itself is point-like since the telescope tracked its movement; the smears are background stars, and the tiny images are hot pixels.

3I/ATLAS is the third confirmed extrasolar object in the Solar System, after 1I/ʻOumuamua and 2I/Borisov. There are likely very, very many more, but they're exceptionally tricky to detect. Similarly, we can expect comets born around the Sun to be passing through other planetary systems.

For all we know, it could be some kind of interstellar Greyhound bus going by... It would be interesting to know what kind of forces propelled it in our direction to begin with. Big bada boom somewhere out there.

Wow!! That's roughly 130,000 miles per second ( had to ask Google). Incredible. Didn't know comets could form around a star. Thanks for sharing. Love to learn at least 1 new thing every day. That gets harder the older you get!

Thanks for the correction. No need to attack! I absolutely despise Trump by the way. Signed 6 petitions against his bill before I had my coffee this morning. Thats just today. Signing everyday. Marched in #NoKings in NJ. Sit outside my horrible representitives office every week. Sorry 4 the mistake

Weirdly, the BBC coverage was entirely on the 'threat to Earth' angle of ATLAS rather than the fact that this thing came from outside the solar system.

Are you sure it's a comet? Could it not also be a spaceship with Aliens on board searching for intelligent life forms in the universe? Sadly, on that blue planet they could not detect any, so they just go on to Proxima Centauri b.

Or so they say! These were visitors from interstellar space on vacation who upon arriving at their designated camping spot realized it was hickville- infested with followers of Orange pissface. So they shuddered, quickly locked their vehicle doors rolled up the windows & hit the accelerator! See Ya!

Hi, I’m interested in the statement that it formed around another star. Is it unlikely that comets might form anywhere else, such as in cold dust or gas clouds? I’ve never thought about it until seeing your post.