If aliens have probed us, I DOUBT we would have actually noticed them. Because, likely the probe would be about the size of one of our satellites and maybe even a lot smaller to cut down on the amount of energy needed to get them here.
Sorry if I take "explosion makes rock go far" as being the more plausible explanation than "Aliens want to wait a million years for a brief glimpse at a distant solar system".
Of course, that is still less likely than some unusual rock doing the same thing.
Playing Devil's advocate, a probe that size would likely visit many star systems, the Solar being a random one in the bunch. The brief pass would be necessary to avoid the energy expenditure of braking and reaccelerating.
1) its shape may actually be more like a pancake than a cigar, a crumpled light sail would match this 2) it showed unexpected acceleration away from the Sun without outgassing. 3) its velocity is very close to the mean motion of our local stellar neighborhood, if you needed to drop a solar sail after deceleration so that it would be hard to work out what system you came from then this would be the velocity to do it at.
I've heard little to nothing in any media articles of anyone supporting alternatives.
Is it once a year these are thought to come through, or 100 times a year? Do we get things that are 100 times smaller at 100 times the rate?
If people won't make a public call, then lets run with aliens.
I was a fan of it's not interstellar, just more fake 'life on Venus' science, but reading some journal articles[1], it seems like it is expected. But it's been hard to work that out.
[1] Realistic Detectability of Close Interstellar Comets https://iopscience.iop.org/article/10.3847/0004-637X/825/1/5...
This is a good reason enough for some people to write a book for a general audience!
Extraordinary claims required extraordinary evidence. A massive rock being hurled to by a supernova to our solar system is far more likely than advanced aliens dumping a ton of future tech to get this huge thing into our solar system for a split second.
Why? Because, it would cost a lot of energy, something I doubt an advanced race would spend. Further, an advanced race that wants to probe us wouldn't need such a huge object, it's far easier to observe from a far (think, james webb telescope but better). Sure, hard to know what aliens are thinking, but it just seems incredibly unlikely they are thinking "Let's build this half mile long space probe for a glimpse of a distant solar system and send it off for a million year journey".
A star exploding and sending a bunch of mass our direction is far more likely. Why? because we know that happens relatively frequently.
While I agree with your overall conclusion, I don't see that we have any evidence that as a race progresses technologically, they spend less energy. The opposite seems to be true.
The problem with "can't disprove" being used as evidence is that you need to consider the full universe of statements that we "can't disprove", but humans tend to think as if "alien probe" is a privileged statement simply because it is cognitively appealing and drives our imagination. If you put it on a list of the things we can't disprove about this particular object, it wouldn't really be the most likely one you'd find.
On the flip side, you also ought to consider the question of all the objects for which we can't disprove they are alien probes. It isn't just this particular object; the solar system is filled with millions of objects we can't disprove are alien space probes, things we've labelled as "asteroids" based on a streak someone took a picture of once. Apply the same standard to all of them that is applied to this object; does it now claim that the solar system is just filled to the brim with alien space probes? Probably not good logic.
Personally, I can't wait until we improve our detection a bit and detect another several dozen things like this object so we can get over this and real science stories can be written about these objects again. Guess this is a taste of what reading about pulsars must have been in the first few years.
Thanks!
Will that do? I also have some whole wheat bread that my kids say taste like dirt.