I thought we were down to 8, now that Goofy or Pluto isn't worthy?
What about Uranus? I heard that was still popular!
Nobody knows for sure.
8 as far as I know. Pluto was demoted.
Not sure, about 8 or 10 years ago.
Funny to think that people say heat death is real when we don't even know for certain how many planets are exactly in our own solar system. Bah.
I fail to see how those are related. Heat death is an inevitable consequence of the way the universe functions. The amount of planets in a solar system varies depending on what kind of star it contains, how much matter was in the star's protoplanetary disc, our observational capacity, how "planet" is defined, and many other factors. You can change the definition of "planet" but you can't change the second law of thermodynamics.
Not really. Bigger telescopes can take pictures of farther away galaxies and objects, but no telescope will ever be able to see past the surface of last scattering, so we will never know how big the whole universe is. The size of observable universe can be inferred from other clues, for example, seeing how far the expansion of the universe has taken the farthest visible objects, or measuring the redshift of photons coming from the cosmic microwave background radiation. The observable universe has a radius of 46 billion light-years.