'Let there be light!' Astronomers make an exciting discovery about the first light in the universe

Stars formed earlier than thought, and died, scattering dust across the universe.

Astronomers have discovered the earliest galaxy yet, born just 600 years after the creation of the universe. The discovery yields a surprise --dust.

LOS ANGELES, CA (California Network) -- Most people are not excited by dust, but astronomers are. Dust comes from stars, primarily stars that have exploded. For a star to explode, it must go through a cycle which involves formation, using up all their hydrogen fuel, and supernova. The supernova only lasts a few seconds, but in that time most of the elements we know are formed and scattered like dust.

Astronomers using the Atacama Large Millimeter Array in Chile discovered the galaxy by using a cluster of galaxies in the foreground to magnify the light from the edge of the universe. The effect is known as gravitational lensing and using special techniques astronomers can see farther back in space and time than ever before.

The galaxy is thought to be just 600 years old, a literal baby in cosmic terms. However, it is filled with dust meaning that some stars have already formed, then exploded between the short 600-million-year time between the creation of the universe and the formation of the galaxy.

This is an important discovery because it means the first stars, and therefore the first light in the universe, "switched on" earlier than believed. It will prompt astronomers and cosmologists to tweak their theories about how the universe formed.

Stardust is the fundamental building block of all matter that we can readily observe in the universe. Other stars, planets, comets, asteroids, as well as our very own bodies,  are made of atoms that were forged in the hearts of dying stars.

Stars are mostly massive balls of hydrogen gas that are so huge that hydrogen atoms in their core fuse together under pressure. That fusion turns two hydrogen atoms into helium and emits a photon, which is a particle of light, into space as well as many other forms of radiation. It's the same process used in a fusion (nuclear) bomb.

As the star uses up its hydrogen, a process that typically takes billions of years, helium builds up in the core and is fused to form oxygen and carbon. Eventually, iron is created and when this process begins a supernova occurs. During a supernova, the core of the star is compressed which caused very heavy elements to form such as gold, silver, and uranium. All of these materials are formed exclusively in this way. The heavier the element, the rarer it is.

The gold in your wedding ring was forged within seconds in the heart of a dying star that existed before the Sun.

Science understands this process very well, and it allows astronomers to calculate the lifespans of stars with high precision. By working backward from their observations, they will now be able to calculate approximately when the first starlight came to be in the universe.

Remember you are dust and to dust you shall return.