Is Vesta the Smallest Terrestrial Planet?

What defines a planet, a decree by an "authority," or the data we learn about an object? The Dawn mission has revealed fascinating information about Vesta, all of which show it to be far more a planet than an asteroid. Here we have yet one more piece of evidence in support of a broad planet definition that encompasses the wide range of objects that both orbit stars and orbit planets, the satellites of stars.

New Horizons Becomes Closest Spacecraft to Approach Pluto

http://pluto.jhuapl.edu/news_center/news/20111202.php
Those with iphones and ipads can now follow New Horizons via a special New Horizons app. Find out more about it here:

http://pluto.jhuapl.edu/news_center/news/20111024.php

New NASA Dawn Visuals Show Vesta's 'Color Palette' - NASA Jet Propulsion Laboratory

New NASA Dawn Visuals Show Vesta's 'Color Palette' - NASA Jet Propulsion Laboratory

The Case for Pluto's Ocean

http://www.centauri-dreams.org/?p=20717

Pluto may very well be one of several planets (I include spherical moons here, which I consider satellite planets) that might harbor a subsurface ocean that could host microbial life. Maybe subsurface oceans will one day be a new defining characteristic for this specific type of planet!

Dawn Mission: Dawn Image of the Day Archive

Dawn Mission: Dawn Image of the Day Archive

Vesta is a complex world. Dawn is showing us that protoplanet are very different from tiny, shapeless asteroids.

ESA Portal - Asteroid Lutetia: postcard from the past

ESA Portal - Asteroid Lutetia: postcard from the past

It seems asteroid Lutetia tried to become a planet!

Occultation Data Show Pluto and Eris Are "Twins"

http://www.space.com/13403-dwarf-planet-eris-pluto-twin.html

In fact, Eris having a higher density than Pluto means Eris likely has a higher percentage of rock than does Pluto, which is estimated at 70 percent rock. This rocky nature is part of what makes these objects planets. We now know definitively that the 2006 IAU decision was based on erroneous information--that Eris is larger than Pluto, which turns out to be false--which only serves to reinforce the notion that that decision was premature.