Just a quick post: according to The Observer, tomorrow (July 11) will be one Neptunian year since the discovery of the planet Neptune. Except…
One year on Neptune is 60,190 Earth days. Neptune was discovered on 23 September 1846, so Neptune’s first birthday will be 60,190 days after this date.
Neptune’s birthday is today, not tomorrow! We’ll all be celebrating on the wrong day!
Never mind phone hacking, this is the real scandal.
Edit: The BBC is even more wrong, claiming Neptune’s birthday is July 12. The philistines!
Double edit: In fact, it looks like we’re all right! July 10 is one average Neptunian year after the date of discovery, July 11 is the day when Neptune will have made precisely one orbit around the solar system’s barycentre (i.e., its centre of mass when you take the Sun and all the planets into account), and July 12 is the day that Neptune will have made precisely one orbit around the Sun. (A figure of July 13 is floating around as well, most likely as a result of an Indian newspaper article which has taken timezones into account). Thanks to Up, Blogstronomy and the Wikipedia users on Talk:Neptune!