I’ve always wondered how astronomers can actually observe galaxies that are millions or even billions of light-years away. What exactly are we seeing when we look at them?

And when scientists say there are hundreds of billions, or possibly trillions, of galaxies in the observable universe, how do they know that if we obviously haven’t seen and counted every single one?

  • hokuspokus@piefed.socialOPEnglish
    6·
    2 days ago

    Thanks everyone for all the answers and explanations! I really appreciate you taking the time to break this down.

    It’s honestly mind-boggling to think about the distances involved, how long that light has been travelling before it reaches us, and just how unbelievably many galaxies are out there. The scale of the universe is very hard to wrap your head around.