Pluto-like objects to be called 'plutoids'

From now on Pluto won't just be any dwarf planet, it will be a 'plutoid.'

The International Astronomical Union (IAU) announced the name today after two years of deliberation. The new classification will be used to refer to bright dwarf planets that spend the bulk of their time outside Neptune's orbit.

So far, Pluto and its larger neighbour, Eris, are the only named objects that qualify as plutoids, but more dwarf planets are expected to follow.

In 2006, IAU members voted to demote Pluto from planet to 'dwarf planet', defined as an object large enough for gravity to make round, but not big enough to clear out its orbit.

At the same time, they also voted to come up with an alternate name for similar, Pluto-like objects. The name 'plutoid' was chosen partly in deference to Pluto's fallen glory.

"In the end, we ended up with something Pluto-like, and I don't think we could have done better," IAU general secretary Karel A van der Hucht, told New Scientist.

But the name is not universally loved. "It sounds like 'hemorrhoid' and it sounds like 'asteroid', and of course these objects are planets and not asteroids," says planetary scientist Alan Stern of the University Space Research Association in Maryland, US.