Couple of places ving. It could go in General Chat (though it's not really general chat because it's astronomy based), Astonomy Science (but that forum was initiated for serious astronomical discussions not for posting inews items from other internet sources) or into News Items Comments (though that was meant for commenting on news items Mike posted at the front of the website).
We (the mods) have been talking about this very issue and trying to work out a best fit solution, so keep your ear open and maybe petition the adminitration
in the Website Feedback forum for a specific forum for these news items.