|Names of Planets and other Moons|
Space MegaConverter #45
Introduction and Overview
Weight is a concept apart from mass in that it varies with the strength of the local gravitation field. Gravity is an unseen force that causes two things with mass to be attracted towards each other. This attraction changes with different masses and the distance between them. The equation that describes the force of gravity is
F = G x M1 x M2 / r / r
where G is a constant, M1 is the mass of
the first object, M2 is the mass of the second object, and r is the distance
between them. Thus, the force of attraction between smaller objects is
less than the force between larger objects, and the force is much less
for objects further away from each other.
Below are several topics of interest.
We would like to especially thank the grade school class of Hellen Tai
at Lynnbrook North Middle School for first suggesting this converter, and
to eighth grader Alexandra Perrotta for writing the section on the Moon.
The Sun is by far the largest object anywhere near us. It is what keeps the Earth and the other planets from hurtling off into space. It is so massive that if it were the same diameter of the Earth, an astronaut would be squashed flat by the gravity as soon as he got near. Even as large as it is, if you could stand on the surface of the Sun (which you can't because it's too hot), you would weigh over 27 times what you weigh on Earth. Even though the Sun is 98 million miles away from the Earth, it's gravity still affects us by causing tides to rise and fall in the ocean.
The Earth is the planet we stand on. When we say we weigh 100 pounds,
we mean that the force of gravity between our bodies and the Earth is 100
pounds. Your mass is always the same, but your weight is relative to where
By Alexandra Perrotta
Have you ever wondered what it would be like to spend a day on
the moon? This information will give you more of an idea of how it
would feel like plus other information on the phases, how the Earth is
effected by the moon and other general information. The moon is the
only natural satellite orbiting Earth. The moon's diameter is 3,480
km.(2,160mi.). The mass of the Earth is 81 times greater than the
moon. Since the moon has no water, atmosphere or weather the surface
will never change. It orbits Earth at a distance of 384,403 km.(238,857
mi.) and at a speed of 3,700 km. per hour(2,300 mph). The moon completes
one revolution in an elliptical orbit in 27 days. For the moon to
go from a new moon to the next new moon it takes 29.5 days. The same
side of the moon always faces towards Earth and it reflects into space
only 7% of the light that falls on it.
For more information go to:
The names of the visible planets were originally given by the greeks representing their gods. The romans then renamed them in their version of the same gods. Later, when moons and other planets were discovered, they were given greek names that somehow figured in with the original theme.
Mercury or Hermes - Messenger of the gods, god of commerce.
Venus or Aphrodite - Goddess of love.
Mars or Ares - God of war. Phobos and Deimos were his children.
Jupiter or Zeus - King of the gods. Son of Saturn or Cronus. The Galilean moons (those first discovered by Galileo) were named for mistresses or boys captured by Zeus and taken to Mount Olympus. The lesser moons, discovered later, were other gods and goddesses associated with Zeus.
Saturn or Cronus - A titan, father of the gods, and king of the universe until he was overthrown by his son Zeus. The largest moon is Titan who were the original inhabitants of the Earth, and the children of Uranus and Gaea or Heaven and Earth. The lesser moons are all Titans who figured in some way in greek mythology.
Uranus - Uranus was the original father of the world. He represented the sky. His mate was Gaea, the Earth, and he fathered the cyclopes and the titans. Of course, Uranus was not discovered until well after Roman times, and was considered by its discoverer a progression from son to father to grandfather, ie Zeus - Cronus - Uranus. The moons of Uranus are named for fairies in greek mythology. Their names are familiar to us because they were also characters in Shakepeare's play "The Tempest."
Neptune or Poseidon - Not discovered until the 19th century, Neptune was named for the god of the deep ocean. The moon Triton was named for Poseidon's son. Nereid was a sea nymph that was loved by Poseidon. Notice that in keeping with tradition, the planet was given the roman name, but the moons were given the greek names.
Pluto or Hades - The god of hell or the underworld. Pluto was
discovered in this century. Ironically, hell is renowned for being a very
hot place, but Pluto is one of the coldest places in our solar system.
The moons of Pluto are named for various servants in the underworld.