3 NEWS– Pluto lost its position as a planet in 2006, and now looks set for
further humiliation.
Currently considered a dwarf planet alongside four others – Eris, Ceres, Haumea and Makemake – new research suggests there could be at least 50 more in the club, which no longer seems so exclusive.
”It’s like being a member of the Qantas Club,” astronomer Charley Lineweaver told the Sydney Morning Herald. “You think you’re elite until you realise everyone else at the airport has a Qantas Club card too.”
To be considered a dwarf planet, a celestial body must have attained hydrostatic equilibrium – another way of saying there are no gravitational imbalances in its structure. Generally, bodies that have attained equilibrium are spherical – Haumea is the only currently-known exception.
Dr Lineweaver and Dr Marc Norman calculated that objects smaller than 400km in diameter are in some cases able to be in hydrostatic equilibrium, and observed small, icy moons in the outer reaches of the solar system that had done so.
Continue reading about Pluto Set for Further Humiliation.
© 3 News, 2010
Photo by flick user Lunar and Planetary Institute
