On a beautiful, clear night, the stars seem so
close you could almost reach out and touch them. How far away are
the stars? What lies beyond them? How large is the universe as
knowing distances, the sky is just a starry bowl over our heads
- like the dome of a planetarium. If we can figure out the distance
to the stars, we will begin to see what the universe looks like
in three dimensions, and we will begin to answer some of the greatest
of questions: How old is the universe? Is it infinitely large?
What is our place in the cosmos?
This website shows how generations of explorers
have taken us, step by step, ever further into the vast expanse
of the universe. It is a journey of discovery that has only just
Third century BC. Aristarchus
of Samos measures the distance to the Moon by looking at the
shadow of the Earth during a lunar eclipse.