In what wavelength? Even the earth glows in infrared, microwave and radio.
But that's the problem planetary scientists find themselves in. They have a lot more data now and there are objects that cover every size from a pimple to galactic superclusters.
I think they should make a contest out of what to call all these objects and give away scholarship money to kids for science degrees. ;)
Visible spectrum. There's bound to be some object that glows barely, so some definite measure of luminosity in the visible spectrum should be set.
"They have a lot more data now and there are objects that cover every size from a pimple to galactic superclusters."
yeah, which is why they really need to come up with some definitions. Even if they end up tweaking them later. Up till now, I think they've relied on obvious differences. Planets were clearly not stars, asteroids were clearly not planets. Comets were neither. And then there was pluto.
I like your idea of the contest.