Astronomers Still Defining Our Planets

Given the huge uproar by the public after Pluto was downgraded to “dwarf planet” status, many people this morning, Thursday, June 4, are scratching their heads over recent news that scientists have started to debate changing its status again.

One of Pluto’s moons, Charon, has what astronomers refer to as “planetary mass.” The mass is higher than the mass of a moon and the center of mass of the system is outside of Pluto. As a result, some now want to refer to the two as a “double planet.” Currently, the Earth and the Moon are the only double planet and only at certain times of the year when the center of mass shifts.

Stephen Murray CCMP Capital says as astronomers are learning new things every day that redefine their understanding of our solar system, this debate could result in bigger changes than simply redefining Pluto as a double planet rather than one dwarf planet with several moons:

Some believe that, based on planetary mass and center of mass numbers, Jupiter would also have to be redefined. Jupiter, a gas giant, did not have enough mass to become a star. Yet, the center of mass between it and the Sun is located outside of the Sun. There’s a small chance that scientists could redefine the solar system as a binary solar system or give it a new description that somehow combines the Sun’s star status and Jupiter’s planetary status.

Leave a Reply