Occupant of C/2019 Q4 to interstellar ticket agent:
"Waddaya mean 1I/2017 U1 has already left? They told me I had a connecting flight!"
ESA scientists are studying an object that has all the hallmarks of being another entity from outside our Solar System, making it the second to be spotted after 2017's cigar-shaped interstellar comet. The observation has, thus far, been a team effort. Gennady Borisov of the Crimean Astrophysical Observatory spotted the thing …
apparently the 'Gentry Lee' sequels DID come in threes (never read them, some people apparently consider them to NOT be a true 'sequel' to the original), but there was only one of the original.
I had nearly forgotten about the 3-ness of the Ramans. Did a 3rd Raman ship ever show up in any of the 'Rama II' series? Otherwise, just two.
Let your imagination take over for a moment, what if this is a precursor to some sort of galactic alignment, and our beloved star The Sun, and it's accompanying planetary partners are slowly drifting into some sort of denser galactic region where millions, nay billions of interplanetary objects are orbiting and this is just the beginning and over the next couple of hundred years, (or couple of thousand), we start to see more and more of these and thus increasing the chance of an impact by one of these objects happening to the world we all live on. What if this is the start of some sort of "Great Bombardment". That's very scary when you let your imagination run a bit wild.
Even at a rate of 2 Million in 2 years there would not be a goot chance of any direct hit with any solar system body, let alone tiny earth ...
However, the night sky view would become spectaclular : Imagine 10.000 active comets when you look up in the dark at night :)
"Even at a rate of 2 Million in 2 years there would not be a goot chance of any direct hit with any solar system body, let alone tiny earth ..."
My napkin suggests that, at a million/year, the earth would be hit within a millennia, although we're having a debate about whether that's an over- or underestimate.
The odds are only so high because they're isotropically distributed. If they were all aligned with the ecliptic, we'd be in trouble for sure.
And Venus looks to have the biggest cross section since it's almost earth sized but orbits at three quarters the earth's orbital radius.
"what if this is a precursor to some sort of galactic alignment"
I suggest stellar explosion zillions of years ago threw these too our way, and so some of the post-explosion bits condensed and had similar size, velocity, and trajectory (eventually heading our way).
sparing the physic calculations (momentum and energy conservation, for example) rocks of similar size and density might have similar trajectories and encounter the same stellar objects, which would slingshot them into similar OTHER trajectories. And so on. Now they're here, curving off to some other destination.
If two objects were chucked out in a stellar explosion "zillions" of years ago on a "similar" trajectory, how far apart would their paths take them in the ensuing time?
Methinks they probably wouldn't even be in the same spiral arm, and probably not even the same galaxy, much less the same solar system. Besides, they came from different directions.
But I'm waiting for the loud retort, the bright flash of light, and the rapid disassembly of adjacent parts when the one they don't see coming hits. I can see the headline now: "Boffins surprised ..."
If they're so expert, why are they always surprised by the unexpected?
Couple of things really, in the entire history of the human race, it's probably only in the last 15-20 years we've been able to look for and find these things. How many have zipped through unnoticed in the past 40 years let alone 4 million or 4 billion ( the time of the "Late Heavy Bombardment").?
The other thing is the Lucifer's Hammer (book) or Armageddon/Deep Impact (films) scenario, we are a very very small speck in the vastness of space, over geologic time something from outside the Solar System may hit us, but that scenario is very unlikely compared to something for the Oort Cloud or Kuiper belt falling in and 'nudging' the planet ( may wipe us out, but it was good while it lasted)
There's not really all that much to compare with as yet. Many Earth samples, a few Moon rocks, various meteorites where we've made best guesses as to their origins and a very few remote sampling/testing of Martian regolith. Everything else is supposition and theory based on distant observations and identification of gases through spectroscopy.
It's incredible what we puny humans have managed to learn, but it's still a tiny amount in terms of non-Earth rock samples.
So let's get this right. The debris floating around several billion years ago from an extinct star or three, that happened to be in the vicinity of Sol when it first ignited is granted local status, but debris from the same extinct stars that have only recently meandered in are classed as outsiders?
A bit xenophobic, don't you think?