Astronomy
Spectroscopy: Reading the Chemical Composition of Stars
Quick fact
The dark lines in a star's spectrum are like a barcode for elements – each chemical element produces its own unique pattern of lines, allowing astronomers to 'read' the star's composition from Earth.
Why this is interesting
Have you ever wondered how astronomers know a star is mostly hydrogen and helium when we can't visit a single one? The answer lies in the star's light itself, hidden in a rainbow.