Observing objects that are far away, and knowing their distances is interesting! However, more importantly, type Ia supernovae have been used to study the expansion history of the universe. One of the cutting-edge type Ia supernovae surveys is The Dark Energy Survey. Visit The Dark Energy Surveys website for more details on mapping out the cosmic history using type Ia supernovae.

Type Ia supernovae surveys show the first strong evidence of an expanding Universe at an accelerating rate. Two teams – the High-Z Supernova Search Team and the Supernova Cosmology Project simultaneously announced the result in year 1998.
Different methods were used by other astronomers to confirm the results of these two teams. The result subsequently led to the Nobel Prize in Physics for 2011. Watch as Saul Perlmutter, one of the three winners of the Nobel Prize in 2011 explains the expanding universe.

Understanding the expansion history of the Universe is the cornerstone of modern day cosmology. The expansion history depends strongly on the composition of the Universe. By studying the expansion history of the universe, astronomers now believe that about 70% of the Universe is made up of dark energy. Dark matter contributes to 25% of the universe, and all the ordinary matter that we can see and sense only contributes to 5% of the universe. Read more about dark energy and dark matter from the NASA website.

Today, astronomers are still working hard on refining the measurement on the cosmic history. This study will carry on for the next few decades. It is important that younger generations will join us in the exploration of the cosmic history. Check out this site about what an astronomer does and see if you are interested.