Scientist says there are over 100 planets in our solar system

Haze around Pluto appears blue in this image captured by New Horizons and processed to replicate the color a human eye would see

The change was a subject of much scientific debate and made no sense said Kirby Runyon, a scientist at the Johns Hopkins University in the US.

If successful, the solar system would have more than 100 planets, including many bodies we now call moons.

If the International Astronomical Union (IAU) were to accept a new geophysical definition such as this to classify objects, then the number of planets in our Solar System would jump from eight to approximately 110!

Pluto is demoted to non-planet in 2006.

Still, Pluto "as everything going on on its surface that you associate with a planet".

There are now four recognized dwarf planets in the solar system other than Pluto, but NASA suspects there could be over 100 such objects that haven't yet been discovered. Pluto's diameter is under three-quarters that of the moon and almost a fifth of Earth.

In fact, astronomers want to redefine the planet's classification based on the geophysics of an orbiting body, not just whether or not it orbits the sun.

Well researchers have asked for a definition for Pluto that tells the intrinsic qualities of the body itself, other than the external factors like its orbit or objects around it. They defined a planet as a "a sub-stellar mass body that has never undergone nuclear fusion".

In 2006, members of the IAU met up in Prague to vote in new rules for defining planets and concluded that Pluto, after 76 years sitting proudly alongside the eight other proper planets, didn't make the cut.

The one point that led to Pluto's demotion was that the IAU standard required all planets and their satellites to move alone through their orbits - and Pluto is too tiny to completely accrete all the matter it passes by on its orbit. While it isn't extended to stars, black holes, asteroids, and meteorites, it does cover pretty much everything else in our solar system - the number of Solar planets would increase from eight to nearly 110. Majority are closely affiliated with geology and other geosciences, thus making the new geophysical definition more useful than the IAU's astronomical definition, they said.

The new definition, which willing researchers can adopt without approval from a central governing body, is also more useful to planetary scientists, Runyon says. The very word "planet" seems to carry a "psychological weight", he adds, so more planets could help pique public curiosity and instill a yearning for exploration in people.

Additional authors of the paper are from the Southwest Research Institute, the National Optical Astronomy Observatory, the Lowell Observatory, and George Mason University.



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