If you thought it was safe to stop checking your astronomical reference books regarding just what is a planet…think again.

Back in 2006, the International Astronomical Union (IAU) passed a controversial resolution spelling out a new description for “planet” - with the upshot being that only eight of the original nine thought to be planets in our solar system truly earn the title of planet, according to the IAU.

Pluto and similar bodies, the IAU put forth, fall into a new category of “dwarf planets.”

That IAU resolution stirred up a sizeable stink. And now the controversy is headed for a major meeting in mid-August to grapple with a key question: Just what is a planet anyway?

The gathering of scientists, as well as educators, will dive into just how we understand what it means to be a planet versus brown dwarf on the larger end and other things on the smaller end, said Alan Stern, the principal investigator on the New Horizons spacecraft. That probe is now outbound to a Pluto-Charon encounter in July 2015.

“This meeting is addressing a serious and topical issue - how planetary scientists determine the central question of planet definition that the mind-bending variety of extra-solar planets and deep outer solar system worlds has forced on us,” Stern told me.

For more information on the August 14-16 conference and workshop to be held at The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, visit:

http://gpd.jhuapl.edu