2.  The Solar System consists of eight planets.  These planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.  Pluto used to be a planet but now it’s classified as a dwarf planet.  The Earth is centered in our galaxy.  But in some other ga

3.  The solar system contains asteroids which are small bodies that are to be left over from the beginning of the solar system 4.6 billion years ago.  They are rocky objects with round or irregular shapes up to several hundred km across, but most are much smaller.

4.  Meteors are a streak of light, usually only lasting for a few seconds.  People usually know them as “shooting stars” or “falling stars”, although they are not stars.  They are caused by the entry of small pieces of rock, dust, or metal from space into the atmosphere at extremely high speeds.

5. AA comet is an icy body that releases gas and dust. MMost comets seen from Earth travel around the sun in long, oval orbits. AAstronomers believe that comets are leftover debris from a collection of gas, ice, rocks, and dust that formed from other planets.

6.  The moon is the only place we’ve visited besides Earth. UUranus has 21 moons. I t is the planet with the most moons. SSome planets don’t even have moons like Mercury and Venus. JJupiter is the next planet with the most moons. It has 16.

7.  Stars are classified into six groups.  These groups are blue supergiants, red giants, main sequence, white dwarfs, red dwarfs, and black dwarfs.  Our sun is the biggest star and is classified as main sequence.  The two main characteristics of stars are luminosity and temperature.

8.  Mercury, Venus, Earth, and Mars are the terrestrial planets.  Jupiter, Saturn, Uranus, and Neptune are the Jovian planets.  The Jovian planets are less dense than the terrestrials and they have more moons.  Also, they are larger in size.  The terrestrials have a weaker magnetic field.