What’s a planet?

Listen 00:06:12

As more and more planets are being discovered, it’s not a bad idea to come to a consensus on answering the question, “What’s a planet?” A new definition of ‘planet’ was suggested by a nationwide team of astronomers led by graduate student Kirby Runyon at Johns Hopkins University.
The new description allows for the inclusion of moons, asteroids, exoplanets and rogue planets by removing the official definition’s requirement that objects orbit the sun and clear their orbital path of all debris.
The current definition adopted by the International Astronomy Union in 2006 doesn’t cleanly cover exoplanets or all the other objects that shoot around the solar system and fall into orbits around the sun.
This suggested definition would be much more useful for everyone involved in solar system studies.

Just another day in the Universe: Discovery of White Dwarf Pulsars
Rotating neutron stars called pulsars were first identified in the 1960’s. They are stellar core remnants comprised entirely of neutrons.
Conservation of angular momentum makes them spin rapidly. They were the only class of pulsars known until now. This newly discovered one is about the size of earth and 200,000 times more massive (just the core of a sun-like star stripped of all the outer gas envelope) with a magnetic field 100 million times greater than Earth’s.

Want a digest of WHYY’s programs, events & stories? Sign up for our weekly newsletter.

Together we can reach 100% of WHYY’s fiscal year goal