eli5: How are we accurately able to study far off cosmic objects if our primary source of information is from light (that sometimes has traveled to us for 1000’s of years). Am I missing something?

Question

eli5: How are we accurately able to study far off cosmic objects if our primary source of information is from light (that sometimes has traveled to us for 1000’s of years). Am I missing something?

In: 8

Answer 1

Not quite accurate. Lots of estimates in astronomy, eg, “there are about 100 – 200 billion” stars in our galaxy.