Counting the grains of sand on a beach feels impossible. There are billions just along one stretch of shoreline. Now picture every beach, every desert, every dune on the entire planet. Add them all together and you get an unfathomable number - roughly 7.5 quintillion grains.
It still isn’t close. Astronomers have estimated the number of stars in the observable universe at around 200 billion trillion - that’s a 2 followed by 23 zeros. For every grain of sand on Earth, there are an estimated 10,000 stars out there.
How do they count? They can’t, exactly. Instead they estimate by counting the stars in a small patch of sky, scaling that across the whole sky, and then multiplying by the number of galaxies - which is itself an estimate of about 2 trillion. The numbers are guesses at the edges of what humans can comprehend. But every time the math gets refined, the universe just keeps getting more impossibly full.
