NPR: An International Astronomical Union panel, which helps define the classification of planetary bodies in the solar system, has unanimously recommended that Pluto retain its title as a planet. Since the discovery of a large number of Kuiper-size objects such as Xena (which are smaller than planets but bigger than most asteroids), some of which are similar in size to Pluto, some astronomers have argued that Pluto should be reclassified as a Kuiper object and not be called a planet. The IAU panel, which deliberated over the summer in Paris, will make its findings known in Prague at the annual IAU meeting later this week. As part of the panels suggested reclassification, planets are going to be turned into three separate categories: terrestrial planets (Mercury, Venus, Earth, Mars), giant planets (Jupiter, Saturn, Uranus, Neptune) and a third class that would include Pluto, which may be called dwarf planets. Pluto may be joined by several more objects in this new category says NPR’s David Kestenbaum. NPR article2006 IAU meetingNews from the IAU meetingOfficial site for IAU planet definition newsThe discovery of Xena
The Week in Physics" is likely a reference to the regular updates or summaries of new physics research, such as those found in publications like Physics Today from AIP Publishing or on news aggregators like Phys.org.