Online Astronomy Education

When you study the planets, stars, sun, moon, galaxies, and other bodies that exist in the universe, you are studying astronomy. Space has fascinated people for thousands of years, but it’s only been possible to study space in depth in the most recent decades thanks to modern technology. While you will study astronomy in school, it’s also possible to get an education in this science in other ways. You can learn a lot about what’s out in space online, and you can also study the stars by going outside at night to look at the sky.


The planets in our solar system move around the sun. Each planet has its own path that it travels along, which is known as its orbit. The closest planet to the sun is Mercury, and this planet travels very fast in its orbit. Venus is the next planet, and this planet has the highest temperature of all of the planets. You can often see Venus in the night sky. Earth is the third planet away from the sun. The next planet after Earth is Mars. After Mars, a lot of asteroids float in space, and then comes the first of the gas planets, Jupiter. Jupiter is the largest planet, and it has more than 60 moons. Saturn is the sixth planet from the sun, and it is known for its rings. Saturn’s rings are made out of rock and ice. Uranus is the next planet, and it also has some rings around it. Neptune is the next planet, and this gas planet also has some thin rings. After Neptune comes Pluto, which is called a dwarf planet instead of a regular planet.


Stars are made of hydrogen and helium, and these gases glow because they are very, very hot. Stars give off energy in a process called nuclear fusion, which produces light. Stars can be many different sizes and colors. The biggest and hottest stars are blue, and the smallest and coolest stars are red. Stars will eventually use up all of their hydrogen, and then, the star dies. When this happens, it collapses, then explodes.

Sun and Moon

The sun is a star and contains the same gases that other stars contain. Although it looks very big and hot to us on Earth, the sun is actually just an average-sized star. The sun’s color is yellow, which means that it gives off an average amount of heat and light. The sun seems so big because it’s the closest star to Earth. The sun is 864,400 miles wide, which is much larger than Earth. You could fit about 1,300,000 Earths inside the sun.

The moon does not give off light. Instead, the moon reflects light from the sun. The sun only lights up the part of the moon that is facing it. The moon moves around Earth, taking a little less than one month to make a full circle. As the moon orbits Earth, different amounts of the moon are visible from Earth. The new moon is the time of the month when the moon isn’t lit on the side that’s facing us, so we can’t see it. When half of the entire moon is visible, it looks completely round from Earth. This is what we call the full moon.

Meteoroids and Asteroids

Asteroids are objects made out of rock that fly through space. Asteroids can be hundreds of miles across or so small that we can’t even see them or know they are there. Many asteroids orbit the sun in an asteroid belt between Mars and Jupiter. Meteoroids are smaller than asteroids, but they are the same type of space rock. If a meteoroid makes it into Earth’s atmosphere, it is called a meteor. These meteors burn up. Sometimes, a piece of rock from a meteor actually falls to the Earth. If that happens, the rock is known as a meteorite.