Presumably Planet Nine is Planet X – without the nut job element (keeping academics safe in their leather chairs). At www.space.com/32478-is-mysterious-planet-nine-tugging-on-nasa-saturn-pro… … astronomers seem to be getting excited about the possible the possibility of Planet Nine and they have gone so far as to try and track its orbit – see also http://phys.org/print379237940.html
At http://phys.org/print379150354.html … supernovae showered Earth with radioactive debris is the headline – a series of massive supernova explosions between 3.2 and 1.7 million years ago, corresponding with the shift from the Pliocene to the Pleistocen (when the Ice Ages kicked in).
At http://phys.org/print379150740.html … supermassive black holes hurking everywhere in the universe. Not just black holes, these are super duper black holes – or stupendous black holes, big as super can imagine.
At http://phys.org/print379159241.html … a unattached Jupiter like exo-planet has been found in close proximity to our Sun, the story begins. It is between four and eight times the size of our Jupiter in the 'solar neighbourhood' – which only means it is not a distant reddened star (or brown dwarf). The paper is at http://arxiv.org/abs/1603.08529
At http://phys.org/print379160478.html … we are back to those ancient supernovae zapping the earth with cosmic rays …
… and at http://phys.org/print379144707.html … the asteroid hunting NEOWISE Mission has published a second year of survey data. A further 72 Near Earth Objects were spotted and logged.