Halley is the one who predicted its return mathematically. I'd say that's more significant than seeing it twice in one lifetime and supposing that it's the same comet.
It's enjoyable, but I've never been really engaged with it. There's no progression, I don't feel like my character, equipment, or ships are getting better even though I'm upgrading things. No planet is special, even though they're all unique.
I think it would be better if you started out in a "settled" region with interesting factions, hand-designed planets, optional quest lines, etc. The infinite procedurally generated stuff would come into play if you push beyond the edges of known space.
A .tar archive is basically only the files cat'ed together, with a header and index added, right?
Tar does not include an index. It's just the headers and data cat'ed together. You have to read from the beginning of the archive until you find the file you want. This is exacerbated if the archive is also gzipped, since you have to decompress all the files leading up to the one you want, as opposed to skipping over them as you could do in an uncompressed tar archive.
So why is there no archive format that just cat'es the compressed files together?
That's essentially what a zip archive does. Each file is compressed separately and cat'ed together with uncompressed headers in between. Also zip archives do have an index which is what allows for random access and easy changes. The downside is that the compression ratio of a zip archive can be worse than a tar.gz archive.
Halley is the one who predicted its return mathematically. I'd say that's more significant than seeing it twice in one lifetime and supposing that it's the same comet.