We live on a planet that goes around a sun. Now, this sun can be seen from many light years away, while our planet won’t be even a speck in light generated by our sun.
Our sun has planets going around it, and this whole thing is called a solar system. When many solar systems are clustered together, generally following the same path of gravity, they get to be called a galaxy, and as many will tell you, there are many many galaxies, each with their billions of solar systems, making up the universe.
We like to term anything that shines in the night sky a star……… so, seen from far away, our sun would be a star. Yet this is not the whole picture, for there are bright objects in the night sky that are not suns.
Let’s return to our own solar system for an example, in fact, two. Venus and Jupiter are well known planets in our solar system. Venus is close to the sun and reflects light so we can see it at night. Likewise Jupiter is a much bigger planet and also reflects the light of the sun, back towards us. Seen from behind, Jupiter would not show any light because it’s actually a planet – a big lump of solid matter, so it is unable to generate power to send out a light big enough to be seen.
Now, I do not know what the people of Jupiter are up to, but their activities are not visible from Earth, so the chances are any energy or light they create is dispersed before it makes it too far into the solar system, never mind the galaxy.
Jupiter is also known as a gas giant which makes it look bigger, but its core is still sold, and cold.
Other light sources in the night sky include stars that have exploded – in other words, ex-stars. Then there are comets, which are lumps of rock and ice. As they get close to the sun they are circling around, their tail will light up and we can see them from Earth.
Meteorites glow as they enter the Earth’s atmosphere and burn up. As there are a lot of rocks in the vastness of space, we sometimes get to see many of these rocks burning up together, and that is known as a shower….. a meteorite shower. They rarely make it to the surface of our planet.
OK, so that’s a quick roundup of the lights we see in the night sky, and to come back to the original question:
The difference between stars and planets.
The most important thing I can tell you on this is, do not try to land, nor step on a star – you will be vaporized. On the other hand, most planets can be landed on, and walked on. Just check that they have an atmosphere you can survive in, and that it’s not too hot or too cold.
In our solar system, the Earth is the only planet we can safely walk on, so take care when visiting other night sky objects, and remember to land on planets only.
