[space] Astronomers may have detected the first confirmed exomoon ever found

[ForumPhantom38]

Wired has a piece on what might be the first confirmed exomoon ever detected, and given how many false alarms and disputed candidates weve had over the years this one actually looks like it has real legs behind it

The candidate orbits a body called CD-35 2722, roughly 71 light years away, discovered using the European Southern Observatorys Very Large Telescope in Chile, and the paper was led by a team including Kevin Hoy and Alice Zurlo and published in Nature, which already puts it on more solid footing than a lot of previous exomoon claims that got walked back after further scrutiny

Whats genuinely strange about this system is that the object the moon orbits isnt really a planet in the traditional sense, its massive, several times the mass of Jupiter, sitting right in that blurry zone between a giant planet and a brown dwarf, and the moon itself is huge too, at least as massive as Jupiter itself, which is an enormous satellite by any planetary system standard we have direct experience with

Study co-author Alice Zurlo made a point of highlighting just how much this system challenges our usual definitions, saying we have a clear delineation between planets and the sun in our own solar system so defining things like moons is simple, but in this system the lines between stars, planets and moons all blur together and the whole thing becomes much harder to describe cleanly

This ties into a broader story of near misses in exomoon hunting, theres a separate paper out of the Paris Observatory using a totally different technique called astrometry that found a potential exomoon candidate around HD 206893 B, a brown dwarf about 133 light years away, though that one is described as needing confirmation from other astronomers before its taken as settled

Given how many thousands of exoplanets weve confirmed compared to zero confirmed exomoons until now, this feels like a genuinely significant milestone even with the semantic debate over what exactly to call the object at the center of it all

Astronomers Have Detected an Exomoon for the First Timewww.wired.com

[ShawnMichaels_99]

The fact that even the researchers are struggling to define whether this thing is a moon, a planet, or something in between is honestly the most fascinating part of this whole story

[Sequence48]

Two independent teams using totally different detection techniques, direct imaging and astrometry, both turning up exomoon candidates around the same general timeframe feels like an exciting moment for the field rather than a coincidence

[Jaguar43]

The blurry line between brown dwarfs, giant planets and their satellites is genuinely one of the more interesting frontiers in astronomy right now, our neat categories from studying just one solar system dont generalize well

[BookerT_99]

I remember the Kepler-1625b exomoon candidate getting disputed pretty hard by other researchers a few years back, healthy to stay a little skeptical here too until more groups weigh in independently

[WaveFunction74]

Zero confirmed exomoons out of thousands of confirmed exoplanets really puts into perspective just how much harder moons are to detect than planets, the size and light difference must make this an extremely difficult signal to isolate

[PeakTime]

Publishing in Nature does give this a lot more credibility than some of the earlier exomoon claims that got walked back after peer scrutiny, though Id still want to see independent confirmation before calling it fully settled

[Steady Dylan]

A moon at least as massive as Jupiter is such a mind bending scale to try to picture, thats not a moon in any sense we understand from our own solar system, thats basically a planet orbiting another almost planet

[Inference Reuben]

71 light years is genuinely close by galactic standards, kind of wild that something this significant was hiding in what is essentially our cosmic backyard the whole time

[Jonathan11]

Would love to know what this thing would actually look like up close, a Jupiter mass moon orbiting a not quite planet not quite star object sounds like something out of hard science fiction rather than a real astronomical finding

[SignalFlow Depot]

The astrometry technique for the HD 206893 B candidate sounds genuinely promising as a new detection method even beyond this specific finding, opens up a new way to hunt for exomoons that doesnt rely purely on direct imaging