[jacquesm]

I think this may be because 'no one knows' is the media equivalent to 'nobody that will talk to us knows'. Effectively that in turn translates into 'nobody in the general public knows' and what with headline space being expensive (if you use shorter headlines you can use larger letters) that got shortened to 'no one knows'.

[frobozz]

It could have been shortened even further to just "". Then there would be nothing misleading in the headline at all.

As it is, the headline suggests that some plane accidentally crossed the Kármán Line, has been floating out there for nearly 2 years, and not even the pilot or ATC could work out how it happened.

[vidarh]

> what with headline space being expensive (if you use shorter headlines you can use larger letters)

At least one of the national newspapers in Norway found a way around the "need" for larger letters: "War type". Can't get larger letters in? Use a suitably aggressive looking font, and you'll make foreigners think you're writing about war when you're writing about a tax increase or the latest minor political scandal.