Source of the post Watsisname, it's on a collision course with the Earth but don't worry the shadow government sent a special team with a hyperdrive generator and it will take a path through hyperspace when it intersects the Earth.
Source of the post it's on a collision course with the Earth but don't worry the shadow government sent a special team with a hyperdrive generator and it will take a path through hyperspace when it intersects the Earth.
Just like Prometheus can travel directly through Mimas shown here:
ALMA has detected a cold debris disk around Proxima Centauri with a mass comparable to that of the Kuiper Belt in our own solar system.
The disk is 1-4 AU from the star, which given the low luminosity of Proxima Centuri, means that it's roughly the same temperature as our Kuiper Belt, and may represent a sort of "Kuiper Belt analogue." The data hints at a possible outer debris belt at ~30 AU as well as warm dust at around 0.4 AU. But these will need more data to confirm.
Interestingly, a marginally detected compact source at ~1.6 AU, assuming it's not noise or a background object, may indicate the presence of a second planet orbiting Proxima Centauri. For a single body to be producing the signal in the ALMA data, it would have to be a ~1000 K brown dwarf, which can be confidently ruled out. Alternatively, this may represent a cloud of dust trapped in the Lagrange point of an as-yet undetected planet. Another possibility is that ALMA is seeing a ring of dust around a giant planet at 1.6 AU (with an orbital period of 5.8 years). The rings would have to have a mass of ~10^-5 Earth-masses, compared to 10^-7 Earth-masses for Saturn. Since the RV data likely rules out a ~100 Earth-mass planet at 1.6 AU, we would be talking about an extremely massive planetary ring around a rather low-mass planet (compared to Saturn at least). Further observations will be necessary to confirm that this emission source even exists, and if it does, that it orbits Proxima Centauri. "At any rate, our study shows that ALMA provides already the necessary sensitivity and resolution to detect rings around exoplanets in Alpha Centauri, and perhaps in other nearby stars."
ALMA Discovery of Dust Belts Around Proxima Centauri
A very important thing not mentioned is that we currently don't know the mass of Proxima b because the inclination of its orbital plane is unknown and thus we only have an estimate of the minimum mass of the planet. But assuming that those belts are coplanar with Proxima b orbit (as the Kuiper and main belts are with the ecliptic) then studying them would allow to meassure the precise mass of the planet! and this would result in knowing the kind of planet we have found (rocky, gas giant, etc...). So this discovery of the belts allow for a better understanding on the habitability of Proxima b as a consequence.
Okay, now I've seen that the scientific paper mentions this. If the outer belt is real then it has an aproximate inclination of i=45º. We also know that the minimum mass estimate for Proxima b is 1.27 earth masses.
Therefore Proxima b has around 1.8 earth masses in reality. By definition this could make it a very small super-earth or an earth-like planet.
They say that the still-to-be-confirmed, outermost belt is tilted by 45 deg, but not the others. As such, and even if the sketch and the animation assume coplanarity of the three belts, it seems not to be observationally established.
Any assumptions about the true mass at this point rely on that assumption. There's no way to know for sure at this point. The confidently detected disk's inclination is unknown, just inferred by coplanarity from the uncertainly-detected outer disk. Which makes the inclination of Proxima Centauri b a lot less certain.
However, if the innermost belt (~10 times farther than Prox b) was confirmed and if the position of its inner and outer boundary were well enough constrained, we could certainly have some constraints on the planet's mass. The constraints would certainly be far weaker if we have to rely on the confidently detected, intermediate belt. Or, more exactly, we could have constraints on the (mass, inclination) parameter. If you are talking about modelling the inner disk edge from the spectral energy distribution, you have to assume the b planet is alone to assume it's mass is responsible for shaping the inner disk wall. If the latter, you can probably infer the inclination, and the HARPS/Red Dots campaign does suggest a second planet is in the system at < 100ish days.
Am I the only one not impressed how this is communicated? The cigar shape attracts much attention, but my understanding is that they simply detected odd variations in the brightness. There may be multiple explanation for that not involving that cigar shape.
It should also be noted that while interstellar asteroids are new (though expected), interstellar dust particles, and even intergalactic particles, have been reported many times based on photographic evidence of fast moving meteors.
It's true that the paper from where this elongated shape is proposed explicitly says "Assuming that 1I's shape can be approximated by an ellipsoid...". This is a fair suposition and if is ellipsoidal it has that cigar shape, but yeah maybe much more complex shapes could allow for the same light curve (I've heard that even a binary object could explain it but I don't remember where I read it).
Also If there are huge albedo variations it could even be a sphere but with different reflectivity in each hemisphere (let's say). But in such small objects I immagine that huge albedo variations are absurd, is all the same material and has been degraded and eroded by the same phenomena (I can't imagine a differenciated geography of a 180 meter sized object). But yeah maybe there are albedo variations, maybe one side experienced a recent impact and exposed a clean bright layer that have been protected from cosmic ray erosion. But considering the slo 7-8 hours rotation of this thing I would found incredible such statement. But yeah makes us think indeed.
Source of the post (I've heard that even a binary object could explain it but I don't remember where I read it).
I read that too, just before "such a compact system would make no sense with the recorded variation period"
Source of the post There are people now considering the possibility of it been a chunk of dark matter O_0 We will see which of these unpublished papers gets finally accepted in the scientific journals. These guys speculate with the idea that if the interstellar object is a very dense concentration of dark matter, then it could have generated a 10 meter displacement in the Earth-Moon system (something detectable using the retorreflectors placed by the Soviets and the Apollo astronauts)
sounds like usual world-ending Nibiru conspiracy *** tbh
Source of the post There are people now considering the possibility of it been a chunk of dark matter O_0
A nice example of how well probed the space of all crazy ideas is. But I don't think this one works. Dark matter cannot condense into such an object for the very same reason that we are unable to see it -- that it does not radiate electromagnetically. A virialized cloud of particles must be able to radiate its kinetic energy away in order to collapse into a solid object. Unless they are proposing that the dark matter was initially produced with such sizes and densities directly out of the Big Bang, (edit: they are), which is an even crazier proposition that raises even more difficult questions.