I've hear several theories stating that the universe is expanding faster than the speed of light, others claim that the universe expands faster the further away you measure it. Which of this is ...
I know Andromeda is our nearest galaxy. But how many known galaxies have been discovered and what are they?
How many of the luminous dots that we see naked are galaxies and not stars from our galaxy? I immagine that the majority of the luminous points that we see naked eye during the night, are actually ...