Planets are large celestial bodies that orbit around a star. In our solar system, there are eight recognized planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Planets come in different sizes and compositions and can have their own moons orbiting around them.
Mars.
The one with no moon
Gravity
yes aliens :)
Because they "wander" through the sky....
rocks, the other planents
the gas giants and the outer planents
Pluto, Ceres, Eris, Makemake. New ones are being added all the time.
orbits around planents or burn up as it gets close to the sun.
Because they emit energy themselves due to various chemical reactions on their surface or core. Planets, on other hand reflect the energy from the stars.
There are in fact many planents within our Solar System that encompass a ring system, however Saturn is the most well known of these.
Earth, Venus, Mars, Io (moon of Jupiter), and Triton (moon of Neptune) are known to have volcanoes. Volcanic activity on these planets and moons can vary in type and intensity.