Shine Bright Like A Diamond: Stars

Stars:

A thousand years ago, humans first looked up into the dark sky and saw the stars; pinpoints of light that had seemed to slowly rotate around Earth. Over time observations have been made by astronomers and we now know more about the stars of our planet.

What are stars made of and how do they help us?

Stars are hot balls made of helium and hydrogen with nuclear fusion at the star's core. They can live billions, possibly even trillions of years, consuming their hydrogen fuel. Stars have played an important part in our universe; they have been a part of religious ceremonies, and helped navigators while they traveled at night in the early years.

Early on, the stars were grouped into constellations by astronomers and they used these to track the movement of the Sun and the planets. The motions of the stars over the course of a full year helped them build the first calendars and to know when to plant fields and when to harvest.

Technology today:

Technology has grown so much that today we are able to photograph images of stars and techniques have been developed to measure the spectra of light coming off of them. Theoretical advances in physics have helped us to understand the different colors of stars and how this matches their luminosity and temperature, and we know that there are so many stars, we know that our Milky Way galaxy contains between 200 and 400 billion stars and that there could be as many as 500 billion galaxies out there with just as many stars. Individual stars are mostly seen in our galaxy, but they have been imaged as far away as 100 million light-years.