The Toughening Pluto Challenge

摘要

WE'RE WARNING YOU: if you haven't yet added Pluto to your life list of telescopicsightings, it's not getting any easier. Plutois edging a little farther into the distanceeach year and will continue doing sountil about 2113. More immediately, it'sheading into the rich Sagittarius MilkyWay — where it will be tricky to identifyamong swarms of other 14th-magnitudepinpoints for about the next 10 years.