SOLAR SYSTEM COMPARISONS

The sun, moon and earth are different from each other. The earth and the moon are relatively small and mostly solid and rocky, while the sun is much larger than any objects in the solar system. Unlike the planets, the sun is a glowing ball of extremely hot gases, radiating immense amounts of heat and light into space, heating and shining on the planets.

The earth has one key and significant difference between the it and any other planet. Earth has the capacity to sustain life. This capacity depends on several other factors: distance from the sun, liquid water, molecules to sustain life activities--including oxygen and organic compounds. Mars, perhaps the moon of Jupiter, may also be able to sustain life, being neither too hot nor too cold, and having atmospheres that may support life. Many planets, but not all, have one or more moons revolving around them.

The sun is an "average" star in terms of size, temperature and age. Although, scientists have not dectected far-off planets revolving around other stars, it is predicted that they do exist.

Description of the sun and planets

sun
our nearest star
93 million miles from earth
produces heat and light by nuclear fusion (Hydrogen Atoms fuse to form Helium atoms; E = MC2
rotates once a month
gives the earth heat and light and is responsible for life on earth
causes tides in the ocean
can be used to tell time and direction

mercury
closest to the sun (36 million miles)
very hot (292 - 800 degrees F)
hard rocky surface--craters and cliffs
almost no atmosphere
rotates once every 59 earth days
revolves every 88 earth days
no moons
gravity 1/3 of earth's

venus
second planet from the sun (67 milliion miles)
very hot (848 - 908 degrees F)
hard rocks--flat areas and rolling hills
carbon dioxide atmosphere / thick clouds of sulfuric acid surround the planet
rotation 243 earth days
revolves 225 earth days
no moons
gravity 9/10 of earth

Earth
third rock from the sun 93 million miles
varies in temperature (-130 - 136 degrees F)
rocky surface (3/4 covered by water)
nitrogen / oxygen atmosphere
rotation 24 hours
revolves 365 days
one moon
gravity 1

Mars
fourth planet from the sun 142 million miles
varies in temperature -190 - 80 degrees F
reddish rocks, canyons, craters, mountains, polar caps of frozen carbon dioxide and water
carbon dioxide atmosphere
rotation 24.5 earth days
revolves 687 earth days
two moons
gravity 1/3 of the earth

Jupiter
fifth planet from the sun 483 million miles
very cold (-238 - -148 degrees F)
small rocky core, surrounded by gaseous surface
largest planet
moslty hydrogen atmosphere
rotation 10 earth hours
sixteen moons (one with an active volcanoe)
red spot on surface (300-year old storm)
gravity 2.5 times greater than earth's

Saturn
sixth planet from sun 886 million miles
very cold -292 to -249 degrees F
small rocky core, surrounded by gaseous surface
hydrogen atmosphere moslty
rotation 10 earth hours
twenty-three moons
winds up to 1100 miles per hour (wanna go sailing?)
can see rings around it (small rocks an dice orbiting the planet)
gravity 1

Uranus
seventh planet from the sun 2 billion miles
very cold (-330 degrees F
rock and ice core, surrounded by gaseous surface
hyrdogen/helium atmosphere
rotation 16-38 earth hours
revolves 84 earth years
fifteen moons
greenish color
rolls like a ball in space around the sun instead of spins, its axis is more perpendicular to the sun than the axis of other planets
has rings around it (9)
gravity 9/10's of the earth

neptune
eighth planet from the sun 3 billion miles
very cold -306 degrees F
rocky and ice core, surrounded by liquid and gas hydrogen
hydrogen, helium, methane gas atmosphere
rotation 16 earth hours
revolves 165 earth years
eight moons
bluish color
has rings around it
gravity 1

Pluto
ninth planet from the sun 3.5 billion miles
very cold -315 degrees F
core unknown, methane ice surface
thin methane atmosphere
rotation 6 earth days
revolves 248 earth years
one moon
gravity ?