Twinkle ,Twinkle , Little star : is today’s science lesson :

Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores. Aside from our sun, the dots of light we see in the sky are all light-years from Earth. They are the building blocks of galaxies, of which there are billions in the universe. It’s impossible to know how many stars exist, but astronomers estimate that in our Milky Way galaxy alone, there are about 300 billion.

Star facts :

The Milky Way Galaxy contains an estimated 100 -400 billion stars, but these numbers are constantly changing as new stars are born and old stars die out.

The average star is between 1 and 10 billion years old, although some stars are older than this. Large stars live shorter lives compared to smaller stars, because large stars burn through their fuel much faster. Giant stars explode into a bright supernova when they die.

When you look up at the night sky with your naked eye all of the stars appear to be the same color, but in actuality they are not. Stars have different colors depending on their temperature. The hottest stars are blue, followed by white, yellow, orange, red, and the coolest stars are brown. This can be confusing because we associate red with hot and blue with cold. Heated objects change colors as they get hotter, a glowing red object is hot but it represents the lowest heat seen under light. As something gets hotter it changes to white and then blue.Our Sun is a green star but white to the eye.

It takes millions of years for a star’s light to reach our eyes, meaning you are seeing stars from long ago. Looking at the night sky is like looking back in time 100,000 years.

“Twinkle, twinkle, little star…” is a real song, but stars don’t actually twinkle. As the light of a star travels into your realm of vision turbulences in Earth’s atmosphere cause disturbances in the light’s path, creating the illusion that a star is twinkling.