Space Space is really big. A pattern of stars is called a constellation. We know distances by parallax effect. The bigger the parallax, the closer something is. One light year is about 9.5 TRILLION kilometers. Polaris, also known as the North Star, has circumpolar constellations circle around it in the night sky.

The Sun The sun is average in size and temperature. A cooler, darker area on the sun is a sun spot. An eruption on the sun is a solar flare. The surface of the sun is the photosphere; it’s where we get light from. The outermost layer of the sun is the corona and it extends far into space.

Stars 90% of stars are on the main sequence, which means the hotter they are the brighter they are. Blue stars are the hottest, and red stars are the coolest. Most stars get energy by turning Hydrogen into Helium during fusion. The largest stars are called supergiants. If a star is big enough, some day it might become a black hole, from which nothing, not even light, can escape.

Galaxies Galaxies come in three shapes; spiral, elliptical, and irregular. Galaxies are made of dust, gas, and stars. We live in the Milky Way galaxy, which has about 1 trillion stars. (1,000,000,000,000). There is probably a super big black hole at the center of the Milky Way. The Big Bang which started our Universe occurred about 14 billion years ago. The Universe is currently expanding (getting bigger).