As inhabitants of the
earth, we are very lucky to have an atmosphere that provides oxygen
in the air so we can breath, water vapor that rains on plants
allowing them to grow, and an ozone layer to shield life from
excessive ultra-violet light. The atmosphere also very effectively
stops particles that fly through space at high speeds and could
wreak havoc on life on earth. Astronomers, however, face another
perspective: in the same way the atmosphere blocks radiation and
particles traveling from space towards earth, it also blocks the
view (in many regions of the electromagnetic spectrum) from earth
into space.
Only in a certain few sections of the spectrum is it possible
to pierce through the atmosphere into space. Visible light makes
it through the atmosphere – which is very lucky for us since
otherwise we wouldn’t have anything to eat, as plants couldn’t
use the sunlight to produce the first sugar! Radio waves can also
travel through the atmosphere without getting absorbed.
